1984 944 Coolant temp gauge is maxed when connected to tachometer.

[Danylok]

My coolant temp gauge is grounding off my tachometer. This wire goes to connector D pin 8 and then to tachometer pin 4 and then only to coolant temp gauge pin 1. when disconnecting the tach pin 4 the coolant temp gauge works like normal but the tach doesn't work. Pin 4 in the tachometer has a trace that connects to ground. So I was wondering if anyone else is getting ground on pin 4 of the tachometer connector?

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[Tom]

My coolant temp gauge is grounding off my tachometer. This wire goes to connector D pin 8 and then to tachometer pin 4 and then only to coolant temp gauge pin 1. when disconnecting the tach pin 4 the coolant temp gauge works like normal but the tach doesn't work. Pin 4 in the tachometer has a trace that connects to ground. So I was wondering if anyone else is getting ground on pin 4 of the tachometer connector? 8ca76e20-5e66-4020-8146-4a7e86380dc6[1].jpg

Welcome to Carpokes! I've done a lot of work sorting out the gauges, at least on the later dashes, so hopefully can help. I'm not entirely following the connector and Pin numbers you are listing? Can you take pics or otherwise clarify? And are you saying someone added that brown wire to the gauges?? There were no separate wires coming off any of the gauges on the oval-dash cars, but I'm less familiar with the early cars.

[Danylok]

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Here is the wiring diagram i found on pelican parts
I found that the wire doesnt affect the tach something else is faulty

[StaceyQ944]

I have a similar problem on my 85.1
I recently replaced the tach and my replacement unit was missing a blade connector, as in it wasn’t built with one, for a single (double brown wire) blade connector. When testing, the tach worked by the MPG gauge didn’t. I was fine with that as the tach is more important.

I later discovered when I would turn the headlights on, the temp gauge would peg off like power was turned off to the car. Turn the lights off and the needle goes back to temp.

I’ve checked grounds and wires with no luck. Hoping someone has ideas for us!

Old Guage with Blade connector circled

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[Danylok]

I have a similar problem on my 85.1
I recently replaced the tach and my replacement unit was missing a blade connector, as in it wasn’t built with one, for a single (double brown wire) blade connector. When testing, the tach worked by the MPG gauge didn’t. I was fine with that as the tach is more important.

I later discovered when I would turn the headlights on, the temp gauge would peg off like power was turned off to the car. Turn the lights off and the needle goes back to temp.

I’ve checked grounds and wires with no luck. Hoping someone has ideas for us!

969BCD4F-CE1B-42DB-A695-941403C7752B.jpeg

Disconnecting the blue and yellow wire on pin 4 on the tach cluster is my temporary fix.