Okay a friend of mine, really a friend not me. He has a 96 lt1 with 6 speed. About two months ago he tried to install a euro light kit to have the lights on all the time even in the day.
In the process of trying to install this himself he was trying to follow the instructions and tap into a black wire on a main wireing harness he shorted something.
After that a number of things stopped working. the milage does not show up on the dash, the abs does not work, the traction control does not work and his climate control (the digital unit) does not work. the mechanic tried first swapping the ECM, no go, then they had the BCM rebuilt and reflashed, there were problems in it but it still did not cure it, they traced all hots and grounds and all were fine. also the stereo does work.
Any ideas where to proceed next?

 

There are reasons why you disconnect the battery when working on car electronics

Where would you start?
Get the FSM and fault find through every affected circuit until you found a common cause?
A elec spike could have torched any of the electronic components

 

A simple step often overlooked would be to check ALL fuses with a test light including the ones in the engine compartment behind the battery. Visual inspection many times fails to identify a blown fuse.

With the key in the "ON" position ground a 12 volt test light lead to the battery negative or frame of the car then probe BOTH sides of EVERY fuse. The test light should illuminate on both sides of each fuse, if it only lights on one side the fuse is blown.

If the test light fails to illuminate on BOTH sides of any fuse try again with the headlight switch turned on. Good luck.

 

The mechanic might be trying his best but the way the post is worded, I wonder if anybody knows what is going on. There is no ECM in a 96. The is a PCM not a BCM. With the items stated as what is not working, I don’t know why that would be item to focus in on. I did not hear anything about the car not running well so why mess with the PCM and its programming. Now that is just another unknown factor in the mix of things.

It's hard to say the wire he was connecting got shorted to ground, or if it got connected to another point putting voltage to areas where there shouldn't be.
There might be a common element causing these problems of a combination of separate ones. One would need to hear all the items not working. Some items are logistically easier the troubleshoot than others. The mileage display is a function of the dash and the CCM. That is fairly complex area and hard to get in and to and work on.

You take one problem at a time and start with the simplest item to work on. For a problem like this you would need the FSM and a basic knowledge of what each system entails in order to have a good place to start.

When you say the climate control does not work, is this the C68 automatic system. And what function does not work. This might be an area to get started in if I knew what the exact symptoms were. The radio is also a simple system to troubleshoot but I don’t know the exact symptoms so no real direction can be offered.

In my off the shoulder opinion you might have a real mess here with lots of separate things not working. I think it needs a person with a high skill level in electronics, and knowledgeable in corvettes. What you don’t need is just a run of the mill mechanic because this problem did not occur naturally but was self induced and anything anywhere could be a cause of a problems. It would be real nice to find a blown maxi-fuse causing all these problem, but one would need lots of good luck for that.

 

If he wanted his lights on 24/7, why did he not just turn the headlights on?

Another example of "If it ain't broke, don't fix it."

And of-"Stock is more reliable."

Like remote starters a lot of these "modifications." Only cause more harm then good. I've seen them fry more than one BCM in a Nissan.

I'd start simple, check EVERY fuse in the car, as suggested.
IF there is not a FSM available get one!!
If you/your friend are NOT proficient in auto electrical find someone who is. Like Gordon Killebrew, the man doesn't need the manual he wrote it.

https://corvettetroubleshooting.com/...eshooting.aspx

FYI, regardless of what you do, even for an experienced electrical diagnostician, this is going to be a crap shoot. Unless, you get extremely lucky.

Good Luck.

 

As I wish I could be of more help with the minimum of details available, it's just really hard to find a place to begin without actually being there and see it for myself.

But I had the same thoughts and feelings that 93Rubie stated in his post. It almost makes you mad that someone took a properly working car and might have done some real expensive damage for no good reason even though it was a mistake. I don’t know what kind of Euro trash light system it is, or what it does, but as 93 said " just turn you lights on".

But as unnecessary that piece of hardware is for the car, lets at least be positive and helpful and not shoot the messenger. Cavi is just trying to help, he did not do the damage and is just looking for any good suggestions trying to help a friend. The owner of the car should actually be on the Forum himself so the actual details are given more accurately rather than thru another person.

 

Trust me i am just trying to help the guy. After all it is his fault i own my 94. I had to buyit after riding in his 95, Before he scre### it up