Malfunctioning gauges after battery terminal replacement

[hasrice@gmail.com]

Yo, got a question for all of you. Recently, I had to replace the positive battery terminal. Turns out the battery didn't have a clamp/hold down. After replacing the connector, the car seems to have hesitate when i come off throttle and idle, then mpg gauge maxes out to the left and fuel gauge drops to empty and temperature gauge goes to cold and all them start jumping around.

When I'm on the throttle all the gauges work fine.

Any ideas?

[Blackout]

Your cluster PCB is most likely F'd.

[dnguyen1963]

Did you disconnect the neg cable while doing this work? If not, then I think your cluster board is shot.

[jlevie]

It is possible that the SI board batteries in the cluster may have reached the end of their life while the battery was disconnected.

[hasrice@gmail.com]

When I first noticed that the terminal broke, I just reconnected it so I could move the car.

While I was working on the car to replace the terminal, the battery was completely disconnected.

If if the cluster board is potentially shot, would the gauges work fine on the throttle?

I'm more worried about the hesitation when coming off throttle, almost feels like its going to stall. I wouldn't think a bad cluster pcb could cause the hesistation. It seems like an electrical issue.

Curious, does the idle auto adjust on m20's?

[Gregs///M]

The cluster PCB being shot is the last thing I would assume. As Jlevie said, your SI board batteries most likely died and need replacing. SI board battery thread


I would also check the condition of the ground cable from the battery. Make sure it is secure to both the battery and the chassis mounting point.

Other reasons, your cluster gauges will jump around is a dirty or loose grounds. They are located on the upper 10mm bolt above the brake pedal. You will see a bracket with a bunch of brown wires with ring lugs. You can wire brush all the ring lugs and tighten the 10mm nut good.

Also, the 7mm nuts behind the gas and temp gauge should be tight. They tend to loosen and cause intermittent operation.

If your cluster board was damaged, the gauges would rarely work, only under heavy bumps or smacking the dash. Or not at all.