Hi everyone I have been working on friends and family'* cars for at least 25 years. Nothing major like rebuilding transmissions or differentials. Mainly Brake work, tune ups and diagnosing check engine lights. I just replaced the W/P on my 1998 Buick Park Ave and discovered several interior features don't work anymore. I had the battery disconnected for about 5 and a half hours, that was the only thing electrical that I touched. Upon starting the engine to check for any leaks and burp the cooling system. I noticed an illuminated air bag light. I later discovered that my interior courtesy lights, rear defogger trunk release button and the digital battery state of charge don't work. I have checked all 3 fuse boxes I found 1 bad fuse under the rear seat but it was for a cig lighter. I pulled each fuse and visually checked them on top of using a test light to see power on both sides. I did remove the lower front splash guard to drain the rad but don't remember any electrical harness or wires involved. Would any body have advice on what direction to go on resolving this issue???

Welcome to the forums Ted, nice to see another Park Ave owner join the forums.

I renamed, and moved your thread to help you get the help you need quicker.

Right off I can only think of one ground wire that I disconnected when I changed my water pump, on my 96' PA there is a ground wire that goes up under the ICM/coil packs, it goes where the bolt on the right side of the alternator bracket.
I am sure somebody will respond with a good pic of where I am talking about, I think Mike may have posted one before, I'll see if I can find it.

Do you have a supercharged L67, or a naturally aspirated L36?

Thanks William I will look at it this weekend and see if that is the culprit. My Park Ave is the L36 and I am very pleased with it. Thanks in advance either way Ted

Very welcome Ted, hopefully that is the culprit, I have the L36 also, it is a solid motor once things like lower intake manifold gaskets are replaced, if you still have the old original lower intake manifold gaskets that are nylon, then I highly recommend replacing them, and swapping out the EGR stovepipe with the one that come with the LIM Gasket kit.

It just dawned on me that you really do not need to remove the ICM/Coil Packs, and brackets above the water pump to remove the pump, mine were removed because I was doing the LIM Gaskets at the time.
I'll post a pic of the bracket I was referring to, if you did not remove it for any reason, then the ground I am thinking of would not be the cause of your troubles.

I seen your second reply & picture. I did replace my lower intake gasket and Plenum assembly @ 50K about 4 years ago. I looked for that wire which as you said is not related to replacing the W/P but it is peace of mind knowing that it is not the cause. I will take an extended look at this situation today and post any result??? Thanks again for your input

William I took my car into a local repair shop that I know the owner of. They were able to look at the body codes and it indicated the wrong module was installed. I told them that was not possible and the module was more than likely bad. So for what I think is a fair price of $560 they replaced the Body control module and everything is back to normal. I guess the money I saved doing the W/P was a wash this time. The car has been trouble free for almost 6 years so I have no regrets worth every penny.

How very strange the body control module failed when you changed the water pump. When you change the WP did you dicsonnect the battery?

That is odd that failed at that time, I am glad you got it fixed, sorry that your WP savings went towards it.
Thanks for updating us on your issue, I'd have never guessed it was that causing those issues.

Roy I did disconnect the battery during the W/P install. When I was connecting the Neg cable it was in a tight spot. for about 30 seconds I struggled to not cross thread the terminal and the cable was making and breaking contact. So The only thing that I can figure is that some how I spiked the BCM. The repair shop couldn't say either way. All they remarked was sometimes these things happen.