Compatible Instrument Clusters

idriveabimmer · Post by **idriveabimmer** » 31 Mar 2005, 09:24

We have a '91 740 (non-turbo) and I'm trying to find a replacement instrument cluster. I have found some on ebay that say they are for the 1988-90 740, but are unsure whether the '91 model is different. Does anyone know if these are compatible?

Also, I have found a 1991 740 turbo cluster. Aside from the turbo guage obviously not being useful for our non-turbo model, does everything else plug in and work properly?

I'm looking for a cluster because the speedometer had been acting up, and then everything on the guage (except the clock) just finally quit working. This weekend I'll pull it out and check all wires for cracks, and check the capacitors, but I just wanted to get started searching for new clusters as well.

Thanks.

LaRy · Post by **LaRy** » 01 Apr 2005, 09:09

Generally I would say that the turbo cluster will work good. At least the impression I got is that Volvo put in what the car will need, but the origin cluster is equal. So most probably the turbo cluster will fit and you can easily take out the turbo gauge meter and use the cover plate from your origin cluster.
If all gauge meters are dead i would look at the voltage stabilisator unit assembled at the back of the instrument cluster. The only unit not using voltage from the unit is the clock, and that is working.
When taking out the cluster, make some notes about connections. It is easy to take out and hard to remember where some connections were placed, especially some flat connectors (AMP).

Guest · Post by **Guest** » 01 Apr 2005, 11:55

Thanks for the advice. I planned on pulling the old cluster out this weekend, but was just curious about possible replacements if I decided to go that way. But it sounds like a used cluster would eventually fail the same way, so I am better off just repairing this one.

I've read some info. about some capacitors mechanical cracking due to thermal stress, so I'll check for those. Also something about one of the ICs breaking as well. Are both of these related to the voltage stabilization circuit, or are they separate issues?

idriveabimmer · Post by **idriveabimmer** » 01 Apr 2005, 11:56

That was me in the previous post. I wasn't logged in. Weird how this forum lets you post as a guest.

LaRy · Post by **LaRy** » 01 Apr 2005, 13:03

As far as I know, and have also my own experience, it is just the speedometer having problems with cracks in IC-circuit. This problem is usually shown like the speedometer does not work some times. Then you give the dashboard a hard hit just above the instrument cluster and it works again (for some time). I don't think it is possible to see those cracks in the IC-circuit. It could always be a good idea to check the electrolyte capacitors, they could change values rather rapidly.
It is definitely a good idea to take out the cluster. I would start to check the different connections on the back and clean them from oxidation. You will find some sort of film distributing the electrical signals and the connections to different units are made by some sort of clamp. It is the same principle as used in the tail light consoles, giving problems.