Electrical Problem

I recently purchased a '92 Deville. I knew it had problems with the battery dying. I tested the alternator and it was bad so I replaced it with a good one. There were small wisps of smoke coming from the crack between the steering wheel and column. I took everything off and discovered a faulty turn-signal switch. I replaced that, problem solved. The trunk pull down wasn't working correctly so I took some wire and made the motor operate down so I could close the trunk lid down all the way manually. I'll wait until later to fix this problem. The last thing, and the one I'm working on now, is the digital display for the speedometer. It does not come on. There have been two instances when it has come on, but it immediately goes back off. I have taken the dash off and did some testing. I am getting the correct voltages at the wiring harness that plugs into the display. So I'm guessing that the board is bad. Is there anyway to test the board so that I can say that it is definitely the problem? Am I missing anything? According to the wiring diagram the display for the fuel center, climate control center and speedometer are supplied power through the same wire in circuit. Is that correct? I bought this car for $75.00, so I'm not afraid to spend some money to get it fixed. Aside from the problems I have mentioned, this car is in great shape cosmetically as well as mechanicaly. So if I can get this last problem solved I will have a great car for my wife to lug the kids around in. Any help or advice would be greatly appreciated. TIA

Hi, I had the same problem with my 93 Deville (the turn signal smoking slighly). The cornering light on mine would stay on when I had to use my turn signal and I had to shake the lever to make it go out untill one day it started smoking. I dont know how to remove the turn signal.This car of mine is my second car and has been out of service for a while untill I can get this resolved......When you removed your turn siganl lever did you have to remove the air bag on the steering wheel?......As far as your speedomiter it could be a bunch of things wrong the best case is it is just a loose connector or maybe a dirty or corroded connector on the back of the dash....... Is it just the MPH that does it or does everything including the fuel data center come on and go out?

How many pins (wires in the connector) were there that plugged into the dash( I have never seen it before).........I know where I work we somtimes have problems with individual wires pushing there way out of the connectors(they just snap back in)............Hope this helps

All the connections seem fine. I'm getting power up to the board. So I'm guesing that is the problem.

Yes I would agree, I saw you question about replacing the digital display with an analog one. I dont think it is to hard to do even tho I have never done it. I have a question about your turn siganl lever..... When you replaced yours how did you do it? Did you have to remove the steering wheel and the airbag or did it just come out from the side of the colum? Thanks

Sorry......I did not notice your responce in my private messages untill now....Thanks again for the advice.

Just to let you all know what is happening. I took the instrument cluster apart. There are two circuit boards. I thought one was to hold all the memory and functionality, and the other was for the actual display. I went to my local pull-a-part and found another display circuit board that matched up. When I got home I swapped the boards and hooked it up. Hooray! It works. I now have a fully functional speedometer display with the correct mileage. The display circuit board cost $7.00. So I got off real cheap here. Total amount of money in this car:
$75 - Car
$31 - Alternator & Turn Signal Switch
$7 - Speedometer Circuit board.

Total = $113.00

This has been a real blessing for my family. We really needed a break like this.