Help, Alternator Hook up for the /6, I thought I had it right! - ZAP, ZAP.. Options

[DougC]

I have a problem where I get a major spark when attaching the battery cables to the battery. Clay Perrine pointed out to me that it's the heavy RED wire that's attached to the Starter (same place as the battery cable) and runs up to the back of the alternator. Clay suggested that this red wire was hooked to the wrong post on the altenator. OK, I removed the complete CIS injection unit and peeled back the engine shoud. The wires were hooked up to the alternator like in Wayne Dempsy's book, the pictures I took upon disassembly were lost so I had to use the book for this. I'm using a newly rebuilt Marchall alt. with external regulator. Here's a breakdown of how I have it wired:

(posts are clockwise from the top)
"+G1" or "+61" = blue wire
"B+" = Red wires [one thick, one thinner]
"another B+" = short ground strap from engine case
"DF" = black wire with spade end
"D-" = 3 small brown wires
"D." = un-used

Where have I gone wrong?

Doug C

[DougC]

Jim, you are probably right about that, I guess I was hoping I wouldn't have to take the wiring harness apart, especially since it was used for the same engine that was in another 914.. I just had to replace the alt, terminals are exactly like the one I replace.

Blogs ? what the *%$# is that? (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

Doug C

[Root_Werks]

QUOTE (DougC @ Oct 3 2005, 11:01 AM)

Doug, are you running your wires to the factory 914-4 relay board? If you are, be careful! They are backwards of what you would think when you hook them up. Dan, can you explain what you mean here? I am using a stock relay board (914/4).. Doug C

On a 914-4 relay board your volt reg plugs into three prongs like this:


| A
........| B
| C

I won't say that A=DF or B=D- ect because I cannot remember that, BUT when you look at the little plug that plugs in just a couple of inches away (The other 3 blade terminal on the relay board), it is this:

| C
.......|B
| A

The terms are flipped on the back blades.

[DougC]

Oh, I see...so just make sure that the wires in the plug (coming to the relay board from the alternator) correspond with the arrangement of the tabs in the bottom of the regulator box, right?

Doug C

[Porsche Rescue]

Doug, are you plugging to the 3 male blades on the relay board? Or are you plugging to the 3 male blades on the bottom of the regulator (visible when you remove the regulator from the board). If you plug direct to the regulator, you then must switch D+ and DF as Dan says.
Dan's diagram of the 3 connector plug from the alternator on a 914-4 is correct, except "B" (which is D-) is offset to the other side when viewed from above.

[DougC]

OK guys, I had the ground strap connected wrong. I corrected that and now no sparks when the battery cables are attached (to the battery) (IMG:http://www.914world.com/bbs2/html/emoticons/clap.gif) . I feel like such an idiot though (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif) . Now, I've reinstalled everthing (CIS unit, etc) and tried starting the engine for the first time last night. It cranked a few times and then.....nothing (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) . I hear the fuel pump and maybe a clicking sound back towards the starter but that's it. When I turn the key to start it I notice that the battery light comes on and the oil pressure light but NOT the "G" alternator light. What should I check first?

Doug C

[Ferg]

Doug,
Great to hear that you are this far, you must be excited...!
If it was cranking, then nothing, start with the starter, make sure it has power, and that it's getting enough volts. Also, that CIS when dry can be difficult. I ran the car out of gas once and drained the battery trying to restart after I added gas. Good Luck and I look forward to hearing that it's up and running! Not long now (IMG:http://www.914world.com/bbs2/html/emoticons/clap.gif) .

Ferg

[sixnotfour]

QUOTE

Also, that CIS when dry can be difficult. I ran the car out of gas once and drained the battery trying to restart after I added gas. Good Luck

Take the air cleaner off lift the sensor plate slowly,with the fuel pump running, it will bleed the air and spray fuel out the injectors . only needs a little ,or you will flood it. You will here a screachinng noise thats fuel flowing thru the system. and you should feel a slight resistance in the plate means its ready,
Now if you get the wiring sorted. Goods Luck

Oh ya check the bulb first

[Porsche Rescue]

Doug,
First, are you sure the battery is fully charged. Battery cables clean and tight? Do you have a good ground at the transmission ground strap? If the starter is trying, but not spinning the motor, it is likely one of the above issues (unless the starter is bad).

Next, the "G" light should come on when you turn the ignition on. It should be off when ignition is off. If the opposite occurs, you have a bad alternator.
If bulb does not light at all, pull the gauge and check the bulb. It must function for the charging circuit to work.

[DougC]

Jim - I'm plugging the VR wires (3 prong plug) into the relay board, the VR (box) sits next to it.

Jeff - thanks for that great tip! I will definately use it. After I hear the thing start cranking again...

Ferg - This thing seems to be on the threshold of running but the electrical part has me a bit stumped. I am excited and ready for this project to be over (by that I mean the car is drivable).

Questions for anyone -

1) Will the car even start without the Alternator light coming on or is it not coming on just because the wire from the alt isn't hooked up to it (somehow).

2) If the main power relay was bad would the battery light and oil pressure light still be coming on (they are when I turn the key).

3) How to check that the MSD unit is not shot? I have it's (small) red wire hooked to a black (powered) wire that originally connected to the +coil and the it's white wire to the blk/purple from the harness. Nothing is connected to the distributor (is that right?)

Doug C

[Porsche Rescue]

Doug,
The alternator and its wiring is not an issue for starting the car, only for keeping the battery charged and running the car off the alternator and not the battery.

I know nothing about main power relays (must be a CIS/911 thing). But if your oil and gen. light come on when you turn on the key, things are OK there.

The MSD wiring is a problem for sure. The white wire goes to the distributor (spade terminal on the outside of the dist. body), red to 12 volt switched power. If you have nothing to the dist. , you have no spark.

[DougC]

Jim you are a big help.. I've obviously been typing as you were submitting. The wording from MSD's instructions had me confused about the white wire. I'll make that change. Also, come to think of it I don't even mave a ground strap for the tranny. I'll stop at FLAPS tonight and pick one up. Any particular place to install it?

two more questions:

1) What terminals connect the alt light to the wiring harness (in and out)? I have a mysterious red wire that comes out of the wiring harness but isn't installed into the plug itself..I'm thinking this is the reason my alt light isn't coming on.

2) (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif) ....I forget the second question.

Doug C

[Ferg]

Went through my old pics (this was my old motor) and found a pic of the harness and the big red wire with taped end and the brown and black wire I think Doug is having trouble with. Can anyone tell from this pic what those two wires are too?

TIA

Ferg

[Porsche Rescue]

You definitely need a ground from the tranny to the body. Get a strap or cable with a hole on each end, about a foot long. There is a small stud welded to the trunk floor near the rear of the tranny. Use some sandpaper to make sure the surface at the base of the stud is clean and "raw". Attach the cable to the body stud and to one of the studs with the 13mm nut at the rear of the tranny case. The stud will need a 13mm nut (wrench size) and washer as well. An alternative is to run a cable from one of the studs mounting the starter to the body. I have one from the starter mount stud to my bulkhead engine mount.

I am confused about an alternator light vs. generator light. I don't think you should have two. I have only one (using a 911 combo gauge). The electrical one is red with a "G" symbol below and is the warning light for the charging circuit, comes on with the key and goes off if engine is running and alternator is charging. The other lights I have are oil pressure (green) and brake warning/e-brake, also red, at the top.

[DougC]

Jim - I meant to say "Generator Light" mines not coming on when I turn the key. I'm talking about the spot on the gauge that's labled "G" . I'm thinking that the Red wire in Ferg's Picture is the reason my Generator light isn't coming on. This wire is presently not hooked up to anything, it's just taped off. If this is the case where should it attach at the relay board?...maybe I could run a wire directly from it up to the back of the gauge or fuse panel? Which fuse?

Doug C

[Porsche Rescue]

Just so we don't muddy the water too much: What I am describing is for a '74 914-4 (my car) which is converted to a six using the 911 alternator and the 914-4 relay board and voltage regulator. I have factory wiring diagrams. If your car is another year (probably the same anyway), let me know.

The wire to the gen. light (red) on your dash should be blue. It is directly connected to the D+ wire from your alternator through the relay board/voltage regulator. The blue wire originates at the relay board (terminal 2 of the 14-pin connector). It connects to the D+ somehow in the relay board/voltage regulator. When you turn on the key it lights and goes out when alternator starts to work. The light bulb in the gauge has the blue wire and a red with white stripe connected to it (same circuit that powers other instruments). The red/white is powered with the ignition switch.
In order for the light to operate, you must have the three wire plug from the alternator correctly connected to the relay board. The plug should have the D+ wire from the alternator in the forward position.

Here is a pic of my relay board and connector. The red in the connector is D+, brown is D- and green is DF. The large connector on the front is the 14 pin to the chassis. You can unplug it and read the terminal numbers on the underside of the plug. Term. 2 should show continuity to the bulb in the "G" hole on the gauge(blue wire).

[DougC]

OK, Jim I've taken several notes and will try to address everything this evening. Thanks for the explanations. One thing though, I believe that that loose red wire I have (pictured) connects to the B+ on the alternator along with the bigger red wire that heads off to the starter. Remember earlier in the post I mentioned that there were 2 red wires on one ring connector to the B+ to the alternator? I wonder what it could possibly be for? Anyway, thanks again..I'll report back.

Doug C

[Porsche Rescue]

We know the large red wire from B+ goes to the starter. I agree that the second red also attaches to B+ (different from mine because I have a Bosch alt.) since they are on the same ring. It will be a hot wire when the alt. is running. I am guessing it fed something other than the regulator in its original 911 life. If so, you wouldn't need it and I would tape it off.
Do you also have a D+ terminal on the alternator? That is the red wire in my pic which goes to the relay board, then through the regulator to the blue wire, and then to the "G" lite on the dash.

[DougC]

The color of the wires that I have for that VR plug are different, I have Blue,Black,Brown..I know the connections to the alt were: blue one was connected to "+61", the black one was connected to "DF", can't remember on the brown. There was definately 3 brown wires connected to "D-" so I'm assuming it's one of those. I will look at their orientation in the plug (at the relay board) to see that they are as you and Dan Root say they should be. I'll be tapin up that loose red hot wire too.

Doug C

[Porsche Rescue]

I would try the blue to D+ on the 3-pin plug (forward, where my red one is). That should light your "G" light when you turn on the key, if it is the right hook up. Kinda makes sense since the wire leaving the board and going to the "G" light is blue also. The offset terminal (brown wire in my pic) would be the D- (your brown) and your black DF would go where my green wire is.

[DougC]

OK I added a ground strap to the tranny, connected the white MSD wire to the electrical prong on the distributor and tried to crank it. The engine cranked like 3 seperate times and really sounded like it wanted to start. After the third crank....nothing! and nothing again, etc..I put the charger on the battery because I'm thinking that my new Optima battery was drained down - left the key in the ignition in position 1 the other night and that may have done it. We'll try again tonight. I haven't messed with removing air from the CIS injection as was suggested 'cause I can actually smell fuel and may even have the thing flooded..The fuel pump runs everytime I turn the key to position 1. Other things I've noticed is that my reverse lights stay on when the key is on and the blinkers tuen on but don't flash. Oh, how can you test a starter?

Doug C