Alternator, ECM, or Dash failure?
Thread Starter
Intermediate
Joined: Oct 2004
Posts: 47
Likes: 1
From: Clearwater Florida
Alternator, ECM, or Dash failure?
9 days ago, I the alt. failed on my '86. I had my mechanic put a new one on. Picked up vette on Monday and dash starts freaking out 
, all lights come and go. You can make out the volt gauge occasionally and watch the volts go down to 11.7 or so. Car starts sputtering and tries to stall. Then out of the blue, dash is normal, volt gauge returns to 13.7, car runs like a champ. I've tried various senarios, driving down bumpy road, cold temp, operating temp, totally random. I've had mechanic double check alternator, check grounds, next is to try to pull codes again (tried Tuesday, but either scanner wouldn't work with OBD 1, or ECM is dead, no reading at all). No check engine light either. Any help or ideas would be appreciated.
, all lights come and go. You can make out the volt gauge occasionally and watch the volts go down to 11.7 or so. Car starts sputtering and tries to stall. Then out of the blue, dash is normal, volt gauge returns to 13.7, car runs like a champ. I've tried various senarios, driving down bumpy road, cold temp, operating temp, totally random. I've had mechanic double check alternator, check grounds, next is to try to pull codes again (tried Tuesday, but either scanner wouldn't work with OBD 1, or ECM is dead, no reading at all). No check engine light either. Any help or ideas would be appreciated.
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Originally Posted by Tvnewsengineer
next is to try to pull codes again (tried Tuesday, but either scanner wouldn't work with OBD 1, or ECM is dead, no reading at all). No check engine light either. Any help or ideas would be appreciated.
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
I agree with jfb, double check the battery cables. My brother's 89 was worked on by a reputable shop and started having similar problems after the job. Being a good shop they disconnected the battery per FSM instructions and when they reconnected the negative battery cable they didn't get it connected right. Turns out a previous repair at a not so good shop had screwed up the cable and if you didn't get it seated just right, the cable wouldn't conduct properly. New cable solved the problem. These cars are actually electrical devices with an auxillary fossil fuel powerplant. Without proper electrical current NOTHING works right.
