I have an '84 automatic....I was going to change my instrument cluster to all LED lighting, and when I took it out I realized that some of the bulbs that appear to be burned out might just not be getting any electricity....the plastic circuit board is trash. There's also a scratch in the front plexiglass (deep) so I'm probably just going to buy another. I'm wondering if anyone can tell me which years would be interchangeable with an 84? I've seen pics of a cluster with "MPG" gauge and I believe the s4 automatics have a gear indicator light in the cluster. Other than that, I have no clue of differences. Help?

 

If I'm not mistaken, I think that when I was looking I found that 84 was only compatible with 84. 85 has too many pins in the connectors and 83 wasn't wired the same.

Roger has new and improved circuit boards with built in LEDs. Talk to him about it at the next breakfast.

 

78
79-81
82-84
85-88
89-95
Those are the groupings of the years for interchangeability.

 

Pretty sure Roger has the circuit boards.

For the front 'glass', you can swap that out. Or maybe polish it (depends on how bad the scratch is).

I took my plexi off and polished it out. No big scratches and it cleaned up nicely.

It's glued to the rest of the cluster housing. But it's not a continuous bead of glue, and after 30+ years, the glue is old and brittle.

I used a putty knife. I found an area that wasn't glued down and slid the knife in. Wiggled it around a bit and could hear the glue cracking loose. Worked it around the outside of the plexi, wiggling and working it to get the glue loose.

Patience and a bit of nerve (the difference between the sound of the glue letting go and the plexi cracking is not a lot) and it came off fine. I used standard 2 part epoxy to glue it back in place after polishing. It has stayed on just fine (5+ years now).

 

Correct on the groupings - however some of the clusters can be different face plate wise (German v USA for example).
I have all the circuit foils except the 89 to 95 which are currently not available.

 

Roger-
When I get some free time I'll track you down to chat about it....maybe you have exactly what I need!

 

Does anyone know if all 85.5 instrument clusters are interchangeable? Have a ‘86 turbo with an LS and want to put a ‘88 N/A overhauled cluster in it? Will all harnesses hook up normally? Any issues with gauge operation that anyone knows of?

Thanks

 

I thought the foil for the 1983 was not available. My euro has the economy gauge also.

 

Are you referring to a 944? The 85.5 is a 944 thing (86.5 for 928's), and there aren't any factory 928 turbos. If you are referring to a 928, you literally have to drift your eyes up 4 threads! Not trying to be a d!ck, but....

 

85-86 have a different tach with lower redline (6250 vs 6600) and lower top speed on the speedometer (170 vs 180)

 

That's good to know, but I wonder what the parts numbers are for the different years? If I were to find one of these on eBay, I would like to know if is the one I actually need, by part number.

 

There must also be some different versions for some of the early years since many of the clusters with 85 mph max speedos have been changed out for some with, I think, 170 mph max.

 

Jerry, I think in the situations you are referring to are people who just swapped the speedos and not the entire cluster. Back when I had my '84 for instance I swapped in a speedo from an 87 which had a completely different top speed on its face but still worked perfectly. The speedo itself is switchable between most if not all of the analog speedometers but the clusters as a whole are only interchangeable in the groupings described above.

 

OK, That makes sense. I still have the 85 mph speedo in my 82. It is funky, but I kine of iike it. Above 85 that I have to roughly determine my speed from the tach. If I ever get stopped I can tell the cop that I wasn't going over 85 - look! My car can only go to 85. Your radar must be needing some maintenance.