Antilock Brake Light / Airbag Light / EATC

[Phido]

I did some searching on the boards for my symptoms and think I might have found the solution, but the thread wasn't too specific. So looking for some clarification / advice.

1994 SHO

• My EATC stopped working while on my way home from work the other day. Completely stopped working, as in no lights, buttons do nothing, etc.
• As I was driving (and freezing) I also notice my Antilock Brake light was illuminated on the dash.

My thought was that there was a fuse that controlled both and that maybe it had blown. I checked fuse 17 which is what I beleive is for the EATC and it's fine.

That's when I found this site, and someone mentioned something about these symptoms and how it is an indication that your Alternator needs replacing. The car has about 130,000 miles on it, and I'm pretty sure the alternator is still the original one. The battery looks pretty shabby as well, and is kinda bulging at the top (almost looks like it's going to burst). The other symptom mentioned in that other thread also talked about the Airbag light, so just went out and checked and my airbag light is on as well.

When I first start to turn the key, without actually starting the car, the EATC does work, and the Airbag and Antilock brake lights on the dash are off. Then when I start the car up, the EATC stops working, and the Antilock & Airbag lights come on, tried revving the car some and when I do that the Antilock & Airbag lights go off or flicker, when back to idle they both come back on. Which does sound to me like at idle the Alternator can't keep up, but when I rev the car up some, it can keep up a little.

So, does this sound like what my problem is? Could it be my alternator that needs replacing, or should I maybe try getting a new battery first (note condition of battery mentioned above). Would a bad battery generate the same types of symptoms I've described? I'd hate to go get a new alternator and have it end up being the battery after all. I'm pretty cheap, and don't want to spend any more than I have to, to get this fixed.

Thanks in advance for any advice you can share, and thank you also for everything I've learned today from reading this site. You guys do good work, and really know your SHO's.

 

[Ishodu]

It sure does sound like your charging system needs help. I would not hesitate in installing a new alt. Also if your battery is in real bad shape it's not going to help the new alt much. Also make sure to charge your battery fully when you swap in the new alt.
BTW do you have a volt meter?

 

[Phido]

Yep, have a Volt meter.

What should I check, just the battery, or is there way to test the alternator?

 

[Phido]

Not sure what happened to my last reply, maybe it didn't get approved or something. Did some more work on the ride today.

Removed both battery terminals and cleaned them and replaced. Tested, same symptoms.

Then got out my voltmeter. Tested batter with the car turned off and found right about 14V. Then started the car and tested voltage at battery again and was very suprised to find almost 20V!!! Talked to a few people and they said that it definitely sounds like alternator at this point, and that the regulator has likely gone bad, which is causing the alternator to provide too much voltage, which is likely causing all of the really weird symptoms I'm seeing. Heading to go price a new alternator now, and will head out this afternoon to pick one up. Will let you all know if it fixed my problem.

 

[Phido]

Symptoms gone after replacing Alternator. Wanted to follow up on forums though to close it out, and maybe help someone else out down the road.

Called around and found a place that had a new one in stock.

Removed current alternator from car to bring with me, so I would have to mess with core charges etc. My bolt pattern didn't really match some of the accounts posted on the site, but I was still able to get it removed. I had two bolts on side facing battery plate, one of which was accessible and the other that I could only get to after removing the idler pully. The third bolt was on the top of the alternator, and the fourth was on the side opposite the batter plate. I didn't have to remove any brackets, those four bolts and it slid right out.

The place where I bought the new Alternator had a test unit, and the guy behind the counter asked me if I wanted to have my old one tested first before I bought the new one. Said yes please, and also asked him to test the new one for me before I left the store with it. The old alternator failed the test with "DC VOLT" failure - bad alternator as suspected. New alternator was tested before heading home, and it tested just fine.

Installation of new alternator was a little easier than removing the old one, becuase I new right where all the bolts went. After it was in place and secured, cables connected, re-installed the battery onto the plate and connected it. Started up the car and all the symptoms described were gone. Car is once again running like it should, and probably most importantly I have HEAT in my car again (Michigan winters can get pretty chilly).

Thanks to those of you replied to help me out, and the other posts on this site that I used for reference and research. Will by stopping by again soon to do some research on struts. All four struts need replacing, and all four coils are busted.... next months project.

Thanks again. :thankyou:

 

[93rev2sev]

Phido,
Hopefully, you will check this thread out again and not just run off into the distance. Don't be too surprised if you need a new battery in the near future. I would replace it just because. If it's been getting overcharged by a bad alternator, it might explode all over your engine compartment...even now...with the new alternator.

I can't say it's ever happened to me, but then again...it won't...ever...cause I'd change the battery if it had bulges on top...

Don't forget to check your ***. You should have one there from me now regarding your struts and whatnot.

 

[Ishodu]

Good to hear you got it sorted out

 

[Phido]

Phido,
Hopefully, you will check this thread out again and not just run off into the distance. Don't be too surprised if you need a new battery in the near future. I would replace it just because. If it's been getting overcharged by a bad alternator, it might explode all over your engine compartment...even now...with the new alternator.

I can't say it's ever happened to me, but then again...it won't...ever...cause I'd change the battery if it had bulges on top...

Don't forget to check your ***. You should have one there from me now regarding your struts and whatnot.

Nope, not running off into the distance. And yes, completely agree with you on the battery. Will do next cpl weeks for sure. It was buldging at the top like that when I got the car about year ago. Hasn't gotten any worse at this point, but just like you said... when I was putting the battery back in place, I was imagining it blowing up while driving down the road and spraying acid all over my engine compartment.

And okey dokey, off to check PM's now.