Imp558 Posted July 18, 2017 Report Share Posted July 18, 2017 The Monte Carlo started this on the way back from our trip to New York over the weekend. I immediately thought it was the ignition switch so I put a new one in yesterday to no avail. Everything goes haywire and then it will stall after a bit, any suggestions? Anybody seen this before? Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 18, 2017 Report Share Posted July 18, 2017 Does the car have any odd add-on accessories like a chime module for an aftermarket radio? I had similar things happen to the Regal when one of the Rendezvous HUDs I had in it went bad. It was polluting the data stream with garbage, nothing would connect and the gauges and HVAC were both totally dead. Imp558 1 Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 18, 2017 Report Share Posted July 18, 2017 I'd start by checking your terminal leads and your ground. I have a top post battery in my 94 Cavalier with the adapters and one of them is messed up so when there's a bad contact it will do funny things like make the gauges jump around. Imp558 1 Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 18, 2017 Author Report Share Posted July 18, 2017 Yes! I found a chime module last night, took me a little while to figure out what the hell it was. Today I'm going to check all the grounds under the hood and then I'll unplug that thing and see if it changes. I didn't realize that thing was run off of Serial data Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 18, 2017 Report Share Posted July 18, 2017 Yep, it is. Serial data connection to the radio to make the car ding because somehow that's easier than a chime box in the car somewhere. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 18, 2017 Author Report Share Posted July 18, 2017 The ground on the front left was a little loose, also unplugged the chime module and same shit. This is looking maybe like a BCM. I'm going to run back to work and grab another PCM for it and try that but after that I'm closing the hood on this thing for a while. We have yet another road trip this weekend and if this car isn't going to cooperate then the Regal will. I'll spend the next couple nights checking and repairing my RELIABLE first Gen. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 19, 2017 Author Report Share Posted July 19, 2017 Tried another PCM, same thing but I did find a ground at the Bellhousing I never put back on and fixed it. That didn't help either so I guess my only reasonable theory is bad BCM? Perhaps running with a bad ground popped it but at any rate this car is parked until at least Sunday. I may make it run and drive it to work until I have time for it. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 24, 2017 Author Report Share Posted July 24, 2017 YAY!!!! Ran to Canton Ohio (Pull-A-Part) and bought a new BCM, stopped at PAP in Akron too. Anyway I put the BCM in and BAM! Everything was exactly as screwed up as before, the BAM wasn't necessary but I did it for effect. The I started looking at grounds in AllData and decided to run out in the dark and check the ground from frame to battery on the right front and the bolt was loose. As it turns out the nut thingy is stripped but applying pressure to it makes it a normal car again so that ground is the problem. At least now I know what I'm fixing, and I learned where some things are on this car so no big deal. Thanks for the input guys, I guess I should have been more meticulous checking the grounds in the first place but I only looked at the stuff I removed when I did the engine swap. I'd start by checking your terminal leads and your ground. I have a top post battery in my 94 Cavalier with the adapters and one of them is messed up so when there's a bad contact it will do funny things like make the gauges jump around. Nas FTW digitaloutsider and primergray 2 Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 24, 2017 Report Share Posted July 24, 2017 Glad you figured it out! Quote Link to comment Share on other sites More sharing options...
98gpgt Posted July 24, 2017 Report Share Posted July 24, 2017 and I was just about to google what a BAM was. At least give me credit for knowing what a BCM was! So that bad ground made your BCM crap the bed? Man I better look my bombs electrics over real careful. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 30, 2017 Author Report Share Posted July 30, 2017 back to no starting. I verified the grounds under the hood. I replaced the computer, jumped it off of the Regal, hot-wired the start relay and I get it to start and run for a few seconds. this is driving me bonkers, I turn the key and there's no gauges for about 3 seconds and then everything comes to life and I hear the fuel pump cycle and there's gas at the rail. Next time going to physically remove and clean every ground under the hood and I have the trickle charger on it right now so I can get it up to a full 12 volts. after that I'm replacing the body control module with the original one and I'm going to do a 30 minute relearn in case this is some kind of vats fluke, I wish I could prove that this car knows it's in neutral but there's no neutral safety switch on the tranny, I guess I can go to the PRNDL input on the computer and see if it's grounded Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 30, 2017 Author Report Share Posted July 30, 2017 I disconnected all the grounds wiped them down and tightened them, put the Grand Prix computer back in it, put the factory body control module back in it, trickle charged the battery, took all the crap off from under the dash and made sure the plugs were ceded to the ignition switch that I put in last week, and it started like nothing was ever wrong. Quote Link to comment Share on other sites More sharing options...
95GS Posted July 30, 2017 Report Share Posted July 30, 2017 Attention to detail. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 30, 2017 Author Report Share Posted July 30, 2017 Had tge marker lights on for like 2 minutes and dead battery. now I know which of the things it was that fixed it. I guess I'm getting a battery in the morning Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.