ref: bentley repair manual

new good price on ebay about $30, good used about $15-20.

some prices as high as about $40. the $30 recycles on ebay. if you don't see it now, you will later.

regards,
byron golden
86 245, 1 owner, 240k+ mi
92 245, owner 2, 136k+ mi

First of all, get a Bentley manual because it has the test for the voltage stablizer that controls the gas & temp gauges. I don't have one with me at the moment, but it's a simple test to do. Or you can just replace the part, it's pretty cheap and easy. Once you get the cluster out and are looking at the back of it, it's that little transistor-like thing all the way to the left. Swap that out for a new one, and while you're at it you should jumper your temperature compensating board, which can give you funky readings on the temp gauge. Do a search for temperature compensating board to find out how and to see the pics. This is also an easy thing to do. I'll bet between the two repairs your problems with the cluster will go away.