Tach & MPG gauges dead, and it's not the battery

[ddavidv]

Have to admit I'm stumped.
When I got the car the tach worked. I pulled the cluster out and removed the 'CHECK' bulb and the service light little circuit board for the LED's. Moved some bulbs around so the right stuff worked and the unneeded ones didn't. Since it's been back together, the tach hasn't operated, nor does the MPG/vacuum gauge. Temp gauge works. I replaced the battery with another good one, and no change. Tested the existing battery and it is fully charged. Re-installed the LED board and no change. Wiggled, cajoled, and creatively cursed everything I could reach and not a jump of the needle.
Does the wide, lower circuit board have a function for the tach? Mine has a rather odd blue-ish area on it that I wonder if it may be contaminated with something.
Anyone have a spare 325i cluster I could try? I don't want to buy anything until I know where the problem lies.

[Nyne]

hmm, didnt drop a soda on the dme?

[Joey Link]

Mine are dead too, but I just bought the car. I should probably see if others can recommend something else before purchasing the batteries.

[e30kappasig]

Same situation here. Guy that owned it before me had stupid "indiglo" gauge faces on the cluster... once i removed them tach and mpg gauges were dead and a new batt didnt fix it. I havent messed with it too much since then...

[mitch500]

yes yes this happend to me when i bought my car. all the guages were intermittent they would work one day then they wouldnt work for months but anyways i read some were once sometimes they just crap out the circutry gets old and stops working. i would say u need a new si board. but who know the guages them self could be bad. remember to always dissconnect the battery when workingon anything electrical.

another thing is you know how there is the three plugs on the back of the cluster the yellow,white,blue. and then there is 2 little wire that you slide onto the posts between the blue connector and the yellow.? yes did u remember to reconnect those two little wires one is green and the other is like grey with a red stripe on it IIRC. but if you forgot those connect them and see what happens.

[BrandonG]

my gas and tach and temp all geek out wen car is started and gas doesnt even work .. i looked up my car on alldata at my dealer adn it says there is a tsb for late model and ealry model e30's 1987-89 for gauge cluster faults so best bet is replace the cluster :) im rebuilding one now for mine out of a 87 is fingers crossed

[JrCamacho]

this maybe a little silly.. but have you checked your fuses? fuse #21 should control those functions. More than likely its blown!

EDIT: way to resurrect an old thread!

[lbreevesii]

I had exactly the same issue when I put the cluster back in my car(they were working prior to pulling it for cleaning).

I asked one of our cluster gurus and he told me to put the green plug into the bottom of it(just the socket, I don't have wiring for it). I was completely skeptical, as I thought that my cluster didn't have one, and that the one I had was from my spare E cluster... popped it in and bam...f'n works.