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914World.com _ 914World Garage _ Starter Relays
Posted by: McMark Nov 10 2013, 03:16 PM
I've been meaning to post this for awhile and Andyrew's recent starter thread inspired me. I used to recommend against a relay at the starter because it was always known as a 'hot start' relay, and hot start issues can be a sign of a wearing starter. So I considered the relay to be a baind-aid to avoid have to really fix the problem - a bad starter.
Jamie (JRust) was having some ignition switch issues and I started to rethink my position on the starter relay. I realized that the crappy reproduction ignition switches that are available now are prone to failure from having too much current pushed through them. They simply aren't built with enough focus on quality to stand up to the way Porsche/VW designed the starting system.
So now I recommend a starter relay on all cars in order to avoid undue stress on either old, tired factory ignition switches or crappy reproduction switches. This can be any 30A or larger relay and Bosch sells a starer relay kit, but I didn't like some of the choices they made, especially because it's sold as a universal kit, which means it doesn't fit nicely on anything. So I put together my own kit designed specifically for our cars. I also found a relay that has a fuse built in, rather than a separate unit.
A starter relay can be made with pieces available from your FLAPS, but for those of you who don't feel like going that route, I've made a few of http://www.originalcustoms.com/store/product.php?productid=14&cat=1&page=1. This thread is more about sharing information though, so I'll exclude the details here.
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Posted by: Spoke Nov 10 2013, 03:39 PM
I like your re-fit. I want one. Looks very clean.
It is '70s technology to run the solenoid of the starter through the ignition switch. Powering an inductor like the solenoid is just bad for the switch. When turning off the solenoid, there is likely an arc across the ignition switch which can lead to premature failure. This isn't done at all today. Most motors, contactors, lighting, solenoids are likely controlled by relays or MOSFET or NPN solid state switches.
Would you please explain what is in your kit and show a schematic of the circuit? I'm curious of the fuse shown in the pic.
Posted by: jvmarino Nov 10 2013, 04:16 PM
I added one to my car a few years back. I still have issues every now and then, but I believe it is due to poor electrical contact of the blade fuse, as fiddling with the fuse holder usually solves the problem when it does happen. It beats crawling under rear tire to jump the started solenoid with a screwdriver (especially if you are on a date 
.
Your design looks nicely packaged, but one concern I would have with the installation location is the relay/fuse will be exposed to the elements (as well as the heat from the exhaust system). Mine is mounted on the rear wall of the engine compartment, and the fuse holder is a rubber capped unit. I am sure mounting it inside the trunk would be even better, I used my location for ease of wiring the retrofit, as well as easy fuse access.
Jim
Posted by: Mike Bellis Nov 10 2013, 04:31 PM
100%
All new cars have a starter relay. The ignition switch should never transfer that much current. Carbon builds up over time and will render the switch useless...
Posted by: jimkelly Nov 10 2013, 04:41 PM
after getting my v8 engine connected to fuel and what not, and running it a little bit in my garage, several times the starter and ring gear did not fully engage. I do not know if my switch is faulty or not. BUT I've been thinking full power (consistently) may not be making it thru and have been thinking about this very thing. thanks to mark for always giving full thought to 914 issues. jim
I stumbled upon these pics I saved to my computer
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Posted by: shuie Nov 10 2013, 05:04 PM
Awesome. I have one in my cart to order. Why is it charging me CA sales tax in the shopping cart?
Posted by: Mark Henry Nov 10 2013, 05:06 PM
Been doing this for 25 years.
Posted by: ConeDodger Nov 10 2013, 05:10 PM
Yes please. 
Posted by: Mike Bellis Nov 10 2013, 05:27 PM
Awesome. I have one in my cart to order. Why is it charging me CA sales tax in the shopping cart?
California charges tax on all online purchases now.
Posted by: r_towle Nov 10 2013, 05:38 PM
Why a fuse?
Posted by: Spoke Nov 10 2013, 06:17 PM
Why a fuse?
I was wondering this too. The only thing I could think of is the red wire comes directly from the heavy starter wire from the battery. When active, the relay connects the yellow wire to the red wire (12V) with no fusing. The fuse must be to protect the relay and wiring from shorts.
Posted by: 76-914 Nov 10 2013, 07:14 PM
Exactly. Nice install. I went the Ford route. +1
Posted by: Tom Nov 10 2013, 07:52 PM
Mark, you are right on with this modification! The contacts in the ignition switch are not designed to handle the arc from the initial closing contact or the arc produced by the break of contact in ignition switches. Relay contacts , however, are engineered to suppress the damage by the arcing so they last longer. The engineers at VM/Porsche did a good job with what they had at the time, but there are much better solutions available now. I already modified my electrical system years ago to take advantage of newer technology or I would be following your advise.
Tom
Posted by: jimkelly Nov 10 2013, 07:53 PM
I assume the high current circuit is grounded thru the starter.
how is the low current circuit grounded? is the another wire I am not seeing?
jim
Posted by: Spoke Nov 10 2013, 08:10 PM
I assume the high current circuit is grounded thru the starter.
how is the low current circuit grounded? is the another wiring I am not seeing?
jim
Good catch. There should be 4 connections: 2 for coil and 2 for contacts. Maybe the case is grounded?
Posted by: jimkelly Nov 10 2013, 08:25 PM
I do see a small wire loop underneath but can't see where it comes from or goes, but this must be it?
Posted by: Elliot Cannon Nov 10 2013, 08:58 PM
So, where to I hook up the big assed wire that comes from my battery? I want one of these but it better come with instructions. 
Posted by: jimkelly Nov 10 2013, 09:38 PM
I think the big assed wire from battery goes to same stud on starter as the red wire pictured above, thus it is where the red wire pictured above gets its power from.
Posted by: Mark Henry Nov 10 2013, 09:47 PM
I think the big assed wire from battery goes to same stub on starter as the red wire pictured above, thus it is where the red wire pictured above gets its power from.
Yep
Posted by: jim_hoyland Nov 10 2013, 09:58 PM
Is that a 3 PIN relay ? Is the clamp The ground ?
Posted by: Elliot Cannon Nov 10 2013, 10:13 PM
I have the Ford relay on my car and have had it there for about 10 years. Where are the people who said it wasn't necessary and even suggested it was rather dumb to install one?? WHO DARES oppose this man??? Who questions the word of the man who my Wife refers to as "the guy in Sonoma with the nice hair"? 
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Posted by: McMark Nov 11 2013, 01:30 AM
Ground is the grey wire in the picture. It goes to the ground lug with the transmission ground strap.
Posted by: rhodyguy Nov 11 2013, 06:40 AM
much more slim line than the BIG ford unit.
Posted by: jimkelly Nov 11 2013, 07:32 AM
this looped wire must the the 4th wire.
it must connect then to switched power from ignition?
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Posted by: type47 Nov 11 2013, 07:57 AM
?? If the grey wire is the ground, then the unconnected spade 
is the signal from the starter switch (not connected 'cause the engine is out of the car?) 
Posted by: jimkelly Nov 11 2013, 08:14 AM
makes sense.
that spade, I didn't even notice it.
jim
Posted by: URY914 Nov 11 2013, 10:22 AM
Posted by: JStroud Nov 11 2013, 11:20 AM
Sounds like a good idea, put one with my oil pump cover, I'll pick them up next time I'm there. 
Jeff
Posted by: shuie Nov 11 2013, 11:26 AM
California charges tax on all online purchases now.
Very well. Paypal sent.
Posted by: Cupomeat Nov 11 2013, 11:34 AM
with the decision and engineering to use a relay for this application and have had one in my car for years (with complete success) however, given that this location (Strapped to the solenoid) will result in high heat loads, have you considered mounting it in the engine bay to reduce its thermal abuse? I agree this is cleaner, but I was concerned about the heat when I put one in on my 914, so my wires are just a little longer.
Posted by: McMark Nov 11 2013, 11:42 AM
Heat may be an issue, but then I know relays of this fashion have been ridging in this location on 914s for years. Something like a Tangerine Header would be my only heat concern because it's so close. But that setup really should have a heat blanket on the starter anyway.
Posted by: Cupomeat Nov 11 2013, 11:52 AM
Heat may be an issue, but then I know relays of this fashion have been ridging in this location on 914s for years. Something like a Tangerine Header would be my only heat concern because it's so close. But that setup really should have a heat blanket on the starter anyway.
If it works, it works... and it is much cleaner this way.
Agree about the header system getting close to it and the need for a blanket.
Posted by: Tom Nov 11 2013, 12:49 PM
I ended up putting mine on the relay panel. Used about 3 feet of 12 ga GLX wire. Also added a push bump start feature for when working in the engine bay and a bump is needed. A weather resistant fuse was also used. Here is a link to my thread.
http://www.914world.com/bbs2/index.php?showtopic=150398&hl=
Tom
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Posted by: rhodyguy Nov 11 2013, 02:32 PM
very clever tom. does the board cover still fit? you should be selling these.
Posted by: Harpo Nov 11 2013, 03:02 PM
however I believe that he was advised against selling them due to the liability of the bump start feature
Posted by: Tom Nov 11 2013, 07:17 PM
Kevin,
Yes the cover fits just fine. See pic. One would not know from the look with the cover installed that there was any starter relay installed unless you look for the extra wire bundle exiting the relay panel.
The liability issue stopped me from offering these as a kit. 
Tom
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Posted by: 76-914 Nov 11 2013, 08:06 PM
Well, I got one before you stopped 
I love it. I would never sue you Tom. I would have to hang a round a bunch of atty's if I sued someone. 
Sadly enough, I had to sell a plane less the prop because I built the prop. Liability 
Posted by: 02loftsmoor Nov 11 2013, 08:32 PM
Mark is there anything moving forward making your relay set up more weather resistant?
Wes
Posted by: larryM Nov 11 2013, 09:10 PM
old timers like me have been doing this on lots of cars besides VW-Porsche using big & tough Ford starter relays - they can carry BIG current!
if you own any older GM V8 you know that the starters get cooked by the manifold heat - and this is the ONLY effective solution!
(i have one on my 1600 VW Manx, and on my 454 Chevy)
Posted by: McMark Nov 11 2013, 09:36 PM
Mark is there anything moving forward making your relay set up more weather resistant?
Wes
Not really. Unless I run across a weatherproof relay somewhere. But I'm not looking. Should this relay fail, it's a 10second swap in a parking lot. Not preferred, of course, but I don't think it would come to that anyway.
Posted by: John Nov 12 2013, 03:29 PM
This thread is real interesting. I have never had an issue other than with a bad starter or starter solenoid. Once we went through several ignition switches with the DE car until we got a good one, but that was it. Never put a relay on the starter solenoid.
I have always been under the impression that the starter solenoid WAS a giant relay that took all the major current of the starter. I have replaced starter solenoids, but the last one I replaced was years ago.
The solenoid throws the sprag out into the flywheel teeth and once fully out, the primary contact closes which powers the starter directly fed from the battery. How many amps does the starter solenoid draw? I wouldn't imagine it is too much for a switch.
Not trying to start anything (no pun intended), and I have read about this "fix" in the past, but never resorted to it. I do know that Porsche in it's infinite wisdom has taxed electrical switches in several instances (headlight switch comes to mind), so I wouldn't put it past them to have a large draw on a set of switch contacts being the root cause of switch failure (ever seen the high beam switch contacts in a 911?). Porsche certainly wasn't fond of over design of their electrical systems.
They did at least follow a common color scheme that has proven beneficial on these old air cooled cars, and in many instances, they did run ground wires in a lot of places where other manufacturers simply scrape paint off with a screw in order to ground a circuit.
I suppose the starter solenoid relay fix is a lot more common than I ever had thought. I still say clean your connections and grounds, but I suppose as a last course of action, I do like the clean look of the small relay either tucked into the eng. comp. relay board or directly attached to the solenoid.
Posted by: Tom Nov 12 2013, 07:15 PM
Initial current thru the ignition switch is 35 amps, goes down as the holding relay takes over most of the current for the starter solenoid. This is per the Haynes manual.
Tom
Posted by: rhodyguy Nov 13 2013, 07:57 AM
tom, if its a liability issue don't bother with the remote start feature.
Posted by: Mark Henry Nov 13 2013, 09:07 AM
This thread is real interesting. I have never had an issue other than with a bad starter or starter solenoid. Once we went through several ignition switches with the DE car until we got a good one, but that was it. Never put a relay on the starter solenoid.
I have always been under the impression that the starter solenoid WAS a giant relay that took all the major current of the starter. I have replaced starter solenoids, but the last one I replaced was years ago.
The solenoid throws the sprag out into the flywheel teeth and once fully out, the primary contact closes which powers the starter directly fed from the battery. How many amps does the starter solenoid draw? I wouldn't imagine it is too much for a switch.
Not trying to start anything (no pun intended), and I have read about this "fix" in the past, but never resorted to it. I do know that Porsche in it's infinite wisdom has taxed electrical switches in several instances (headlight switch comes to mind), so I wouldn't put it past them to have a large draw on a set of switch contacts being the root cause of switch failure (ever seen the high beam switch contacts in a 911?). Porsche certainly wasn't fond of over design of their electrical systems.
They did at least follow a common color scheme that has proven beneficial on these old air cooled cars, and in many instances, they did run ground wires in a lot of places where other manufacturers simply scrape paint off with a screw in order to ground a circuit.
I suppose the starter solenoid relay fix is a lot more common than I ever had thought. I still say clean your connections and grounds, but I suppose as a last course of action, I do like the clean look of the small relay either tucked into the eng. comp. relay board or directly attached to the solenoid.
Since I started doing the Ford relay fix back in the late 80's it been common knowledge that the Bosch solenoid takes a minimum 9 volts to kick it, where as a Ford solenoid only take 3 volts.
I did not "invent" this, I first heard of the fix from Gene Berg although he didn't "invent" this fix either.
Sorry I've always chuckled at the blowhards that tell you to replace (hack) wiring and switches, spends hours chasing grounds, etc. I have never once cut into a factory wiring harness (other than repair other PO's hacks) or replaced an ignition switch (and now these switches are burning out). The solenoid works every time if it's just a resistance issue and never took more than a 1/2 hour to install.
Posted by: Tom Nov 13 2013, 12:46 PM
Mark henry,
I think you have AMPS and VOLTS mixed up. The Bosch solenoid takes a minimum of 9 volts to operate at initial pull-in of 35 amps. After the internal contacts close the hold-in circuit, the amps fall off to about 11 amps.
Tom
Posted by: Marty Yeoman Nov 13 2013, 01:50 PM
I've had one installed in a similar location for about 10 years now.
Hasn't failed yet.
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Posted by: andys Nov 13 2013, 01:51 PM
To rig up a non-Ford relay, it should be rated in the 40 amp range, correct?
Andys
Posted by: ClayPerrine Nov 13 2013, 05:17 PM
I just use a high torque, gear drive starter. They don't pull the draw in amps that the stock bosch starter does, they turn faster, and they never suffer the hot start issue.
Posted by: Drums66 Nov 13 2013, 09:19 PM
I just use a high torque, gear drive starter. They don't pull the draw in amps that the stock bosch starter does, they turn faster, and they never suffer the hot start issue.
...."Thankyou"(and the beat goes on!)
Posted by: dfelz Nov 14 2013, 12:21 AM
Mark, or anyone else please tell me which numbers go where!!
Thanks!
http://s1293.photobucket.com/user/dfelz914/media/Mobile%20Uploads/photo_zps1adee85a.jpg.html
Posted by: type47 Nov 14 2013, 05:53 AM
30 and 87 is the circuit that you want to supply power to. One terminal (30 or 87) will be connected to the starter solenoid and the other to +12 V (starter terminal from battery). 85 and 86 is the control of the relay circuit. When not energized, circuit is open. Connect either 85 or 86 to the wire from the ignition switch (likely to be yellow with female spade connector), the other terminal to ground. When the key is turned to start, the control circuit closes the relay and that circuit provides power to the starter solenoid.
Here's a "Ford" relay with terminals/connectors:
the spade connector to solenoid is a female connector and the spade connector to ignition switch is a male connector. All the ring terminals in the above diagram (connections on the relay terminals) will be replaced with female spade for your relay.
Would you detail manufacturer and PN of your relay?
Posted by: Mark Henry Nov 14 2013, 08:31 AM
Mark henry,
I think you have AMPS and VOLTS mixed up. The Bosch solenoid takes a minimum of 9 volts to operate at initial pull-in of 35 amps. After the internal contacts close the hold-in circuit, the amps fall off to about 11 amps.
Tom
Yep sorry, I was in a rush out the door yesterday and never proofread my post.
Posted by: dfelz Nov 14 2013, 09:08 AM
30 and 87 is the circuit that you want to supply power to. One terminal (30 or 87) will be connected to the starter solenoid and the other to +12 V (starter terminal from battery). 85 and 86 is the control of the relay circuit. When not energized, circuit is open. Connect either 85 or 86 to the wire from the ignition switch (likely to be yellow with female spade connector), the other terminal to ground. When the key is turned to start, the control circuit closes the relay and that circuit provides power to the starter solenoid.
Here's a "Ford" relay with terminals/connectors:
the spade connector to solenoid is a female connector and the spade connector to ignition switch is a male connector. All the ring terminals in the above diagram (connections on the relay terminals) will be replaced with female spade for your relay.
Would you detail manufacturer and PN of your relay?
Awesome, thanks for the run down.
I guess i should have asked this earlier, but, if i have an IMI-101 hi-torque starter, is a 30A relay big enough?
Posted by: ripper911 Nov 14 2013, 09:30 AM
I've had one of these on my car for years. Definitely cheap insurance to make sure the car starts, but you have to buy blade type fuses 
.
http://www.autoatlanta.com/Porsche-Starter-Relay-Relay-Hot-Start-Kit-Parts-PN-RWR1.html
Posted by: Mark Henry Nov 14 2013, 09:40 AM
IMHO the Ghia horn relay is a POS for this app.
I replaced 2 horn relays with ford units this summer. I think I still have a brand new Ghia horn relay sitting on my scrap pile.
Posted by: worn Aug 22 2015, 12:15 PM
I've been meaning to post this for awhile and Andyrew's recent starter thread inspired me. I used to recommend against a relay at the starter because it was always known as a 'hot start' relay, and hot start issues can be a sign of a wearing starter. So I considered the relay to be a baind-aid to avoid have to really fix the problem - a bad starter.
Jamie (JRust) was having some ignition switch issues and I started to rethink my position on the starter relay. I realized that the crappy reproduction ignition switches that are available now are prone to failure from having too much current pushed through them. They simply aren't built with enough focus on quality to stand up to the way Porsche/VW designed the starting system.
So now I recommend a starter relay on all cars in order to avoid undue stress on either old, tired factory ignition switches or crappy reproduction switches. This can be any 30A or larger relay and Bosch sells a starer relay kit, but I didn't like some of the choices they made, especially because it's sold as a universal kit, which means it doesn't fit nicely on anything. So I put together my own kit designed specifically for our cars. I also found a relay that has a fuse built in, rather than a separate unit.
A starter relay can be made with pieces available from your FLAPS, but for those of you who don't feel like going that route, I've made a few of http://www.originalcustoms.com/store/product.php?productid=14&cat=1&page=1. This thread is more about sharing information though, so I'll exclude the details here.
That is a nice setup Mark. BTW, we will be traveling the same route. Me Seattle to Wisconsin and you to Michigan. Offer of help still stands.
I bought one of the Ford tractor relays and it seemed really beefy. So I checked the resistance - about an ohm. So the poor switch would be running 12 amps to run it, supposedly reducing the current?!
I checked a relay similar to yours. Just a 30 amp relay I had lying around. 70 ohms. So that would be a far better solution. Just thought I would add this because I bought the tractor relay based on some of the posts in the forum, and then came to the conclusion that it isn't a good match.
Posted by: Geezer914 Aug 22 2015, 12:55 PM
You don't need a ground unless the relay is isolated from the body.
Posted by: jimkelly Aug 22 2015, 04:56 PM
so the ford solenoid has a much bigger load than a mcmark style relay? good to know as I was leaning ford too. thanks : )
--below/above --
"That is a nice setup Mark. BTW, we will be traveling the same route. Me Seattle to Wisconsin and you to Michigan. Offer of help still stands.
I bought one of the Ford tractor relays and it seemed really beefy. So I checked the resistance - about an ohm. So the poor switch would be running 12 amps to run it, supposedly reducing the current?!
I checked a relay similar to yours. Just a 30 amp relay I had lying around. 70 ohms. So that would be a far better solution. Just thought I would add this because I bought the tractor relay based on some of the posts in the forum, and then came to the conclusion that it isn't a good match."
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