Hey all

I have a strange electrical issue. Hopefully someone can help. Here is the story, I am in the process of bringing a 88s4 back to life. Did a TB, WP and intake refresh last fall. Started the car after that job, all seems well, but had to get a starter button since I discovered the starter wire in the front harness was toast. I also decided to redo the interior over the winter.

Ok I rebuild the front harness, and put most of the interior back together. Started the car yesterday, and it was awesome, ran great. Celebrated last night. I ran the car for a good 10-15 mins yesterday.

I get in the car today, turn the key, hear a small click, then everything has no power. The electrical system goes completely dead. Ok think dead battery, check it, 12.5 Volts. I disconnect the battery from the car, and hook it up to a charger, wait a few hours, go back still all dead.

Check my terminals, All seem good, but pos term is somewhat loose, I remove it, clean it while it is off, put it back on, car comes to life. I think great, easy fix, get in the car, turn the key, Click all dead again. I discover that if I disconnect the neg, no effect, but if I disconnect the positive term, the car will come back to like.

I checked voltage at the jump term and CE, and I am getting 12 volts.
Any ideas. I am thinking one of my relays might be bad, but which one, I swapped all of the top 53 relays, and no improvement.

 

Could the solenoid on the starter have died? Happened to me in a 944. One hour before it happened the starter worked fine, then CLICK.

 

would the solenoid kill the entrie electrical system???

 

Bad groundstrap. Not the connections. Strap itself.

 

After the strap you posted a while back, I would not be surprised.

 

Sorry to act so certain, but its becoming a classic symptom.
Especially out east here when a car gets bannished outdoors. Lots of moisture.


Had to rescue CPayne & his S4 one day from parking lot where he works.
Same exact thing.

Seen a bunch of them now. If body-side, its due to water collecting and strap sitting in it. Can happen on the battery side as well.

 

I thought this thread was about home protection, but I'll chime in anyway.

+1 on the ground strap.

Has anyone tried to refurbish one yet? Maybe some kind of etchant and agitation to get rid of the corrosion? It's pretty easy to clean up tarnished silver, there's got to be something for copper.

 

Forgot to mention, I went to advance auto, and got a new cable... Thought about that as well. One thing I did not like when I install my front harness, was how the battey cable connected to the selonid. I remember thinking this could short out. I will chaeck as soon as I can, but I have to wait until next weekend.

The other wierd thing is that low power consumption, raido etc run fine, but high amp stuff will give me the death. I tried to tunr on my lights, and same thing happened. They came up first, then all went dead.

 

Wow. I'll assume you polished the brass body contact for the negative.
Red little one that powers the CE panel, then.

But you're talkin about a major power disconnect.

Possibly ignition switch.

(Am also assuming you already pulled the CE panel, replaced all fuses, polished relay pins. Then went through all the ground points and cleaned them. Kinda Porsche rescue, electrical chapter 1 )

 

My vote.

 

yea did the grounds all around in the fall, also did the ce panel then as well. got the dremel tool out and cleaned up the contacts. i am worried about the switch as well. also a battery short since this shows up under load. also reading some other forums, i will need to make sure the connections on the starter are good as well.

since turning on my lights caused the issue as well, i think the issue happens when load is placed on the battery, and i bet it has a short. going to get it tested.

 

sorry but, you might have picked a different title for your thread in light of one of the stickys above? i know you're not being insensitive but perhaps you might change the title?

 

With the electrics dead (that is, after failure), use a test light (not a meter) to check the following by having one terminal on the first location, the other terminal on the second location.

Positive post (not terminal) - Negative post (not terminal)
Positive post (not terminal) - bolt on chassis where the ground strap is attached
Positive post (not terminal) - clean metal on chassis
Positive terminal (not post) - clean metal on chassis

If every one of these, tested exactly as specified, gives exactly the same brightness of the test light, it is time to get under the car and continue the testing.

Terminal (not bolt) on the main battery cable attached to the starter solenoid - clean metal on the engine
The bolt where the cable is attached - clean metal on the engine.
The jump start terminal - clean metal on the engine
The main power connections on the top of the Central Electrical Panel - clean metal on the body
The main power connections on the top of the Central Electrical Panel - terminal on the ground connections above the Central Electric Panel.

Let us know if every one of the tests, done exactly as specified, give exactly the same brightness of the test light.

 

hey wally thanks for the input. looks like what you are advising me to do will actually search for my short. i will do this, but unfortunately it is going to have to wait until saturday. i have to travel this week.

i have a powerprobe tool that i like, but i will use a lamp since it is not the fact that i have pos volts or ground, but how bright the lamp is.

chuck z sorry about the title. i thought it described the situation. might be too literal, and i will keep that in mind for the future.

 

Ok First I changed the title.

I was able to get back to this last night. I am going to have to get a test lamp. I use a tool called a power probe that will tell me if I have a positive or a ground at a certian spot. here is what I found out.

I disconnected the Battery wire at the starter, and the battery side showed a pos as expected, the engine harness showed a ground.

I then reconnected the two at the starter, and disconnected the engine harness at the jump point. I got a pos on the harness, and a ground at the jump terminal.

I then reconnected, and moved toward the top of the CE, and again I got a pos on the two wires going into the CE, and a ground on the copper plate on the top of the CE.

That is as far as I have gotten, and then I went to the study the wiring diagrams.

So I think my power distribution to the CE is good, and my short lies in either the ignition switch itself or somwhere in the CE. I pulled the CE last night and tested it with a volt meter, and it seems to be good. Fuse 24 was blown, so I will track that circut down for a short. it is the rear hatch release, the glovebox light and the diagnostic connector. It also supplies power the ignition switch, although I have not quite figured that one out yet.

I plan to remove the top row of relays and see if I can get power to return. I will also check for continuity on the ignition switch at the different positions at the A and B plugs on the CE.

Just going to see if I can trace the short reading the wiring diagram....

I will also do the test light procedure after I get a test light as Wally P suggested, but I think the power probe accomplished the same thing. At least I got power back to the top of the CE. It is just when I connect it there, things are sorted out.

I am hoping it is just my starter relay... But I doubt it.