Tach jumping

Mudd · Mudd's Garage

1987 944. Driving to the shop to get the brakes worked on, I noticed that the tach would go to zero and then back to where it was supposed to be. This happened several times on the 5 mile drive. Any ideas.

Gawernator · Gawernator's Garage

Could it be a ground problem?

mytrplseven · mytrplseven's Garage

Possible issue with bad cable connection on back of tach in gauge cluster. Also check grounds for bad connection.

Mudd · Mudd's Garage

Where would the ground associated with the tach be.

John_AZ · 09-19-2012, 04:39 AM

Information might be found in the Pelican "Tech Info Center" found on the top of the page ^^

Pelican Technical Article: Solving Strange 944 Gauge Problems...

Or in the WSM Electrical Volume IV

GL
John

Guest765 · 09-19-2012, 11:32 AM

Sometimes the gauges just get old too. My rpm gauge sticks at zero every time i start the car until and unless i give it a thwack with my knuckle. Never drops to zero after that though, so it does sound lke a loose connection as mentioned above.

ditch68 · ditch68's Garage

Thanks for that link, John. My fuel gauge always says "3/4" even when full, and when it reads empty, I still have like 7 gallons left. Maybe it is that and not the sender like I thought.

I need to pull the cluster anyway to do something about my extremely dim dash lights as per usual.

My last 951 did the same thing with the fuel gauge.

Will report back, I may try it all this weekend if I have time.

Jeff

Gawernator · Gawernator's Garage

My fuel gauge starts a little above 3/4 when full, goes up to almost full and then gradually works down. I have gotten it down to the "R" mark once, but a low fuel light never came on. i don't know if that means I wasn't low enough on gas or if the light just doesn't work :S

rmcdonnell · 09-20-2012, 10:13 AM

It was some time ago, but I found that if you tap the gauge and it starts working again, then there is probably a dry joint on the tach pcb. I made some suggestions on how to find it and fix it.

Fixed; Intermittent tach

cheers
Rissole.

Tom944 · Tom944's Garage

I had the same problem with the fuel gauge and temp gauge reading low. I pulled the gauges out and cleaned the "football" shaped ground connectors. Whole job took less than an hour. Gauges read correctly now.

Mudd · Mudd's Garage

how hard is it pull the gauges out.