Instrument Cluster Failure

[Lolvolol]

I have a 1993 940 that had a wonky fuel gauge that was intermittent, and things went downhill from there. I pulled the instrument cluster and resoldered (heated and added a bit of new electronics solder) all of the connections. Everything started working again. The heat/cool cycle and hidden corrosion (tarnish, really) eventually cause cracks and make solder joints that look good actually non-conductive. For anyone with electronics experience, this whole job takes about 15 minutes.

The caramel color might be electrolytic capacitors that have leaked and failed. These capacitors look like little cylinders. Generally speaking (all applications) they often fail simply due to age.

Your problem may be due to something completely different.

I’m honestly not sure what this stuff is, but am I wrong in thinking that the best idea may be to just find another cluster? Lol

[BEJinFbk]

That looks a factory applied conformal coating.
If you take a closer look, it’s been used around
surface mounted capacitors and resistors.
It’s used as protective layer.

[Lolvolol]

That looks a factory applied conformal coating.
If you take a closer look, it’s been used around
of the surface mounted capacitors and resistors
It’s used as protective layer.

That’s odd, I’ve looked at pictures of other 850 clusters and didn’t see the same coating. But if it’s intentional, then that’s good I suppose.

[MRScott]

It is definitely applied during manufacturing. Seen it plenty of times over the years. Not seeing it on others might be due to the rolling changes often made during production. Such as, it's been discovered these sections need corrosion protection.

[Lolvolol]

It is definitely applied during manufacturing. Seen it plenty of times over the years. Not seeing it on others might be due to the rolling changes often made during production. Such as, it's been discovered these sections need corrosion protection.

Okay I gotcha. Thanks for clearing that up. Not too sure if I should still try buying another cluster or not though, I don’t believe it to be the wiring harnesses, and I don’t believe it to be the ABS because usually it’s just the speedo and tach that die if that’s the case from what I’ve read, and Ive tried jiggling the key in all sorts of ways, so I don’t believe it to be the ignition switch either

[xanthefin]

It might be a good idea to check the connector at the ABS control module and the connectors going into the back of the instrument cluster. If they're loose, corroded or damaged they could cause the gauges to stop working.

Something else I just noticed is that my clock is staying on constantly now, and the clock is the only thing that works other than the boost gauge. It’s odd to me that the clock will appear, but the info screens will not.

That info screen wont appear is most likely your info switch and that computer has broken connection between them.

[Lolvolol]

It might be a good idea to check the connector at the ABS control module and the connectors going into the back of the instrument cluster. If they're loose, corroded or damaged they could cause the gauges to stop working.

Something else I just noticed is that my clock is staying on constantly now, and the clock is the only thing that works other than the boost gauge. It’s odd to me that the clock will appear, but the info screens will not.

That info screen wont appear is most likely your info switch and that computer has broken connection between them.

I don’t think it’s the switch because the info screens went out at the same time as all of the gauges

[misha]

The only way to fix the issue or at least to find out if it' just a bad cluster....is to replace it with a used unit.

[Lolvolol]

The only way to fix the issue or at least to find out if it' just a bad cluster....is to replace it with a used unit.

And that’s what I’ll try. Any recommendations as far as finding a reliable source on one?

[misha]

Allready pointed you into a right direction...few posts earlier.