84'-86' instrument cluster swap

Have 84' 528e speedometer and odometer not working, bought complete instument cluster from 86' 528e. Installed in car and speedo and odo worked fine but nothing else! No tach, no fuel, no mpg, no temp and lights above fuel ga were on regaurdless of switch position. Being the ingenious sort I decided to install the 86' speedo in 84' cluster. well this didn't fare any better as speedo and odo didn't work. I spent 40$ and i'm back at square one, should I buy odo gears for my old speedo, will this fix my problems?

Yes, your old speedometer has the broken gears. Just replace those and you should be fine. Your new cluster probably has bad SI batteries that have leaked and destroyed the board with the acid. When I bought my car only the speedometer worked (or was it the tachometer?) and nothing else. Bought a good condition SI board, replaced it and everything works since then.

I had same issue with nothing but the speedometer working, and gears didn't fix the problem.
My issue was the SI board to get the tach and gauges going, and the little motor to turn the gears on the odometer. I used a "parts cluster" to repair mine. Took a little while but it all worked out.

just soldered wires onto 86' SI board (to mount batteries in remote location)going to install in car and see if it works. Volt meter showed dead battery but no leaks, looked new.

Originally Posted by jimoreno

Yes, your old speedometer has the broken gears. Just replace those and you should be fine. Your new cluster probably has bad SI batteries that have leaked and destroyed the board with the acid. When I bought my car only the speedometer worked (or was it the tachometer?) and nothing else. Bought a good condition SI board, replaced it and everything works since then.

Thanks Jim, installed 86' cluster in car with remote batteries and all works well.

That's great!