Hi as a new owner of a 90 red convertible that i finally found only 4 miles away from were I live and 2ND owner of this car, which I call the nicest 2 seat-er convertible I have sat in and drove, the large man's car with lots of room. I just love this car and probably will be asking many questions here. One question I have is my dash when we drove on a long trip the dash would go blank and a light would come on and say electrical problem. Then it would come on again and off again for hours. So I noticed under the hood alot of the black wire covers were so brittle to the touch they would fall apart I replaced them and check the conections and wires. The next time we went out for over a 2 hour drive to the lake the dash worked fine. Then I went to pick up some food and on the way there it went out two times. But the next day all the way home it worked fine again. Any suggestions on were to look? what to do or if any one has had this problem before. Thanks and happy motoring!

Hi and welcome to the forum! You are at the right place for information on your Reatta. I don't have a 90 so I will let someone better answer your question but it is normally caused by a bad connection where the unit plugs into the dash.

You may benefit from visiting my website. (see my signature line below) There is a lot of information there for new owners.

The problem is usually in either A. The connection to the instrument panel cluster, B. The instument panel cluster itself.
Try taking it out and cleaning the connection, if it still does the problem thn look for a replacement. I am looking for one myself.

Thanks for the information i purchased a 90 repair manual and still waiting for it to arrive you have to take the dash apart for that. Have you ever done this hope the manual shows me how. Thanks again any information is greatly appreciated. Mark

Removal of the dash panel is pretty easy. There are 4 torx screws, 2 above the Instrument Control Panel [IPC] and 1 in the top edge of each heat/ac vent. After you remove them carefully grasp the trim panel working your fingertips under the panel. The trim piece is made up of 2 elements, metal top piece and plastic backing piece. The trim panel is held in place by a number of self grasping clips. After you get that panel off you will see that the IPC is held in place by 4 more torx screws. Remove those and gently grab the IPC on either end and with a slight rocking motion pull off. The plugs are held in place by the back of the dash. Do not attempt to remove then unless you want to spend about 30 minutes trying to get them back in place.
Spray both the male portion of the plug on the IPC as well as the female plug in the harness with electric contact cleaner and reinstall.
Replacement is the reversal of the removal.
It took longer to write this then it did to do this. I have removed several from cars out in the local u-pick yard for others. I presently do not have any for sale

Good instructions Dave. I added it to my website.

I found a IPC on ebay if anyone wants to scoop it up.

http://cgi.ebay.com/ebaymotors/90-93-BUICK-RIVIERA-REATTA-DIGITAL-CLUSTER_W0QQitemZ370081657729QQcmdZViewItem?hash=item370081657729&_trkparms=39%3A1%7C65%3A1%7C240%3A1318&_trksid=p4506.c0.m245

Don't pay more then $100.00. I will get more.

When ya do let me know also!
Thanks

I pulled 2 IPC's from a couple of '90 Rivvy's, this morning. I'm going to check them out to see if they are any good. Since they were in cars that were crashed, I'm hopeful they will be okay.

The only way I have of checking is using my Reatta...anyone have any better way to check? I have one of these for a friends Reatta that has the 00 problem. The other one if good will be available for sale, if anyone is interested.

The local U-pull sometimes has Riv's that I get the IPC's from and put on ebay. The thing is while I give them a not-DOA warranty, I have no way to really test them (my brother wouldn't appreciate me tearing his dash apart all the time).

I believe there are IPC testers which sometimes are seen on ebay

Thanks, Philip...I'll keep an eye out for one on E-Bay.

In the meanwhile, ...the only way I have is my car.

If the yard leaves the key in the ignition, just take out a portable power station and just power up the car...

That would work but obviously an issue if the car is pretty well parted already and who wants to sit in a nasty dead car in a yard staring at the IPC for a few hours to make sure it won't cut out?

I stick with my method for the moment. I'm about to install one in my car. I'll run with it for a few days to check for anamolies...stay tuned for an update.

One Good(I think, it least it fires up) - One Bad!

Back to the yard for a replacement. Thank goodness I bought it with a warranty!