1993 SSEI inst cluster doesn't work / works then goes crazy

[Frank Friter]

Hello all,
I'm having a issue with my instrument cluster. Fuel, oil pressure, temperature, boost, compass, and info screen done work. (Speedo and RPM gauge works) For most of the time they don't work, and sometimes they go crazy (bouncing all over the place) and the odd time they work. Also when the gauges don't work my steering wheel controls don't work. When the gauges work the steering wheel controls work. I've cleaned the grounds underneath my kick panels, changed the battery and cleaned the battery connection. Does any one have any other ideas on how to fix it?

[94SCSSE]

I had the same issue on my 94 SSE about 15 years ago. After giving up and taking it to the stealership they said it was the ECM and replaced it but it did not fix the issue. Somewhere I had heard that if the alt dropped below 14.1 volts the ECM would do crazy stuff??? I check my alt and was only getting around 10 voltz due to badly slipping belt. Replaced the belt and the problem was resolved. Hope this gives you somethings to check into.

[J Wikoff]

I'd try pulling the gauge cluster out and reseating the connectors on back, and maybe some buried further in cluster itself. The corresponence with the wheel controls might and probably to say something... but I don't know what. I'm sure someone does here.

[willwren]

Checking your ground busses under the front door sill plates (behind the carpet) for corrosion would also be strongly advised. The cluster grounds through there.

[harofreak00]

I've cleaned the grounds underneath my kick panels, changed the battery and cleaned the battery connection.

[willwren]

I've had to go back into one side 3 times until I got all the corrosion on the ground busses on my 95. And cleaning the battery connection (as we all well know) may only be half the problem. Remove the boot, and peel back the insulation. There may be corrosion working it's way up inside the cable.

[steveg]

I've had this problem on several of the 1992's sse's I've owned. By far the most
common problem is the conformal coating used on the pcb used on the instrument
panels pc board. The conformal coating is too thick and it doesn't match the thermal expansion coefficient
of the instrument panels pcb material. This results in the microseparation of the solder joints from the chips, leads plated thru holes from or to the various devices. Over time the coating also will crack all over the circuit board causing those irritating intermittents that drive one nuts. Now how to fix it. You'll have to get a conformal coating removal solvent solution and remove the coating. Miller Stephenson makes several conformal coating strippers i.e., 114 and 115. I've found that most of the problems are around the Motorola controller chip and surrounding chips. The underside or underneath the chips is key to releaving the stress on the solder joints. You have to get as much of that conformal coating off as you can. I took the boards down to the lab and inspected it under a microscope before I stripped the coating and I could see various solder joints fractured and separated. After stripping the coating I used a solder pencil with a .010 inch tip and resoldered all the controller and surrounding chips devices and plated thru holes. All of the sse instrument panels that had intermittents worked perfectly after resoldering with no problems. I didn't bother to reseal the pcb with new conformal coating in case I missed a solder joint that I would have to revisit in the future. This has worked on 4 sse instrument panels so far. They all previously had wandering or crazy gauges, some had intermittent instrument dic displays, some reset the trip meter. You have to remember that those older National Semiconductor cmos chips were sensitive to changes in to resistivity of the interconnections. Regarding electrical grounds- the ones I've found that were most problematic are : below the ignition module, the frame grounds at right and left side of the front driver and passenger fuse and relay panels. One of the worst grounds is the main interconnect behind the passenger side glove compartment behind the air bag assembly. It comes in right next to the main electrical harness and provides the branch grounds all over the ip, the ground next to the battery on the frame and dc on the opposite side by the widow washer tank. Hope this helps.

[SSEBonne4evr]

You realize this thread is over 6 yrs old?

Please start a new thread for you problem.