Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> Question for the electrical gurus Wierd stuff happening, when I turned the key for the first time
rick 918-S
post Aug 4 2011, 10:21 PM
Post #1


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
I connected a booster charger to the cables on Sandy's Ravenna car tonight for the first time just to see how this would pan out. When I got the car there were no keys, the fuse panel was hanging down and the gauges were hanging out of the dash. The engine was out so there was no way to check to see what was working and what was fudged.

The engine is now installed, Jeff Bowlsby went through the engine harness and it checked out. I pulled the column and replaced the switch and wiper switch.

Everything on the relay board looked fine and is plugged in. Here's what happened when I turned the key on:

MPS is buzzing loudly

The Generator light on the combo gauge is flashing

the tach in bouncing around 3000 rpm's.

Now there is no battery in the car just a booster charger but I don't understand the wierdness with the dash and specially the MPS. (IMG:style_emoticons/default/WTF.gif)


All wild suggestions welcome.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mike Bellis
post Aug 4 2011, 10:26 PM
Post #2


Resident Electrician
*****

Group: Members
Posts: 8,345
Joined: 22-June 09
From: Midlothian TX
Member No.: 10,496
Region Association: None
I would check and clean every ground in the car first. Wierd things happen with bad grounds. Then I would double check the gauge cluster and relay board wiring.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
larss
post Aug 4 2011, 10:43 PM
Post #3


Member
**

Group: Members
Posts: 428
Joined: 10-September 09
From: Sweden
Member No.: 10,787
Region Association: Scandinavia
I suspect that the booster chargers output is not perfectly DC there is possibly some AC in i making things jump around. Check with a battery instead.


/Lars S
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Aug 4 2011, 10:54 PM
Post #4


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
QUOTE(larss @ Aug 4 2011, 11:43 PM) *

I suspect that the booster chargers output is not perfectly DC there is possibly some AC in i making things jump around. Check with a battery instead.


/Lars S


That's why I mentioned I only had a charger on the cables. I'll toss in a battery and try it again.

The flashing generator light may have been crossed up with the flasher somehow.

Maybe the tach is plugged in to the incorrect terminal on the coil. (IMG:style_emoticons/default/confused24.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Aug 4 2011, 10:56 PM
Post #5


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
QUOTE(kg6dxn @ Aug 4 2011, 11:26 PM) *

I would check and clean every ground in the car first. Wierd things happen with bad grounds. Then I would double check the gauge cluster and relay board wiring.


Brand new ground strap on the transaxle. cleaned combo ground next to the relay board, wire wheeled the ground cable both ends.

Relay board could be an issue.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mike Bellis
post Aug 4 2011, 11:01 PM
Post #6


Resident Electrician
*****

Group: Members
Posts: 8,345
Joined: 22-June 09
From: Midlothian TX
Member No.: 10,496
Region Association: None
Check the ground above the fuse panel too. Electricity takes the path of least resistance. Even if that is through another circuit. Current will look for a "more negative" source even if that is not a true ground.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Aug 4 2011, 11:13 PM
Post #7


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
QUOTE(kg6dxn @ Aug 5 2011, 12:01 AM) *

Check the ground above the fuse panel too. Electricity takes the path of least resistance. Even if that is through another circuit. Current will look for a "more negative" source even if that is not a true ground.


Ya, I need to look there.

I installed a battery and the tach and MPS issue is cured.

The generator light is still flashing but much cleaner just like it's wired through a flasher. I'll have to check that section. I think someone may have been fuching with the dash stuff.

Also no crank of the starter. That shouldn't be too hard to figure out.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Aug 5 2011, 02:28 PM
Post #8


Custom Member
***************

Group: Members
Posts: 24,574
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States
check that your relay board ground (underneath it on the inner fender) is good.
Check that you have power at the starter when the key is in the start position...
Ed uses a little trick.
Put it in neutral and use a quarter to jump from the large positive lead on the starter to the little spade bit on the starter (where the yellow wire plugs in).
A quarter fits nicely.

There are three (I think) little red wires on the positive batter terminal along with the large starter wire.
Red feeds the ignition switch....yellow comes back down to the starter from the ignition switch.
You can see then on top of the tunnel near the shifter.
Put a pin through the yellow on and put a volt meter on the pin and ground...turn key to start position...should light up (or use a test light)

Voltage regulator looks like a pack of cigs on the relay board...
Pull it out (its got a screw) and clean up all the crap, then put it back in....shake it around gently while you have it out (ask Ed)

Check all your fuses, you may have blown one or two without the battery in place.

RIch
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Aug 5 2011, 04:56 PM
Post #9


914 Idiot
**********

Group: Members
Posts: 14,986
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California
You probably have the battery and brake warning light wires switched around. Easy to do, results in a battery light that flashes when the handbrake handle is pulled up.

I've never heard an MPS buzzing! That's very weird indeed!!

--DD
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Aug 5 2011, 05:05 PM
Post #10


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
QUOTE(Dave_Darling @ Aug 5 2011, 05:56 PM) *

You probably have the battery and brake warning light wires switched around. Easy to do, results in a battery light that flashes when the handbrake handle is pulled up.

I've never heard an MPS buzzing! That's very weird indeed!!

--DD



Cool! I was just heading out to the garage to look at the wiring stuff. I'll check that. The gauges were hanging out of the dash when I got the car. It's very likely things got switched.

Ya, the MPS buzzing was really wierd! (IMG:style_emoticons/default/unsure.gif) Once I put a battery in the car and got rid of the booster charger it stopped. (IMG:style_emoticons/default/confused24.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Aug 5 2011, 05:10 PM
Post #11


Custom Member
***************

Group: Members
Posts: 24,574
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States
ac, dc, different things.
Need a battery to run a car, it smooths out the wavelength.

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
EdwardBlume
post Aug 6 2011, 05:48 AM
Post #12


914 Wizard
**********

Group: Members
Posts: 12,338
Joined: 2-January 03
From: SLO
Member No.: 81
Region Association: Central California
Doesn't electric things go wacky when the alien ship is nearby? (IMG:style_emoticons/default/huh.gif)

Sorry, couldn't pass that up...
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Aug 6 2011, 06:44 AM
Post #13


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,460
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
QUOTE(RobW @ Aug 6 2011, 06:48 AM) *

Doesn't electric things go wacky when the alien ship is nearby? (IMG:style_emoticons/default/huh.gif)

Sorry, couldn't pass that up...


(IMG:style_emoticons/default/unsure.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 17th May 2024 - 11:34 AM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
All rights reserved 914World.com © since 2002
914World.com is the fastest growing online 914 community!
We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ...