944 no rpm indication

[P.Viby]

Hi.

Today I cranked up my old 944 for the first time in 2 years. It has been parked for over 10 years and my plan is to get it back in shape and then enjoy driving this now old fine car.

Believe it or not, after installing a new battery it fired up after 3 seconds. Simply amazing if you ask me.

Problem is now that I don't get any RPM indication on the instrument cluster. Rest of the gauges work fine, but the RPM needle seems dead.

Any help on where to start ?

Edited December 18, 2014 by P.Viby

[P.Viby]

Any help here guys ?

 

Would be really nice to put back into mint condition.  

Edited December 28, 2014 by P.Viby

[wvicary]

It's probably a fault in the cluster, the simple act of disconnecting and connecting the electrical cables for the cluster might solve the issue or a simple  thud on the dash might bring it to life. 

[P.Viby]

Tried with disconnecting the cluster / battery with no luck. Also a few thud on the dash did not bring it back to life.

 

But 2 absolutly very good suggestions :thumbup:

[P.Viby]

Anybody know if i would be able to connect a reader to the car in order to see if the RPM sensors are working ?

[wvicary]

The RPM signal is sent from the motronic unit and you'd need to check the wiring diagram for details. I've sent 911 tachs out for repair and can recommend Palo Alto Speedometer, give them a ring and perhaps they can shed some light on the issue and might know of a common fault with the 944 cluster. Sorry I couldn't be of more help.

[P.Viby]

The RPM signal is sent from the motronic unit and you'd need to check the wiring diagram for details. I've sent 911 tachs out for repair and can recommend Palo Alto Speedometer, give them a ring and perhaps they can shed some light on the issue and might know of a common fault with the 944 cluster. Sorry I couldn't be of more help.

In that case I guess it should be able to read the RPM out of the Motronic unit and check if this is a sensor or cluster problem.

[wvicary]

If it's running it won't be a sensor as the speed sensors are inputs to the Motronic so you'll need to find the output signal from the Motronic to the cluster and monitor that for signal.

[P.Viby]

If it's running it won't be a sensor as the speed sensors are inputs to the Motronic so you'll need to find the output signal from the Motronic to the cluster and monitor that for signal.

Okay - in that case I am quite sure it is in the cluster the problem is.

Anybody knows how to take the cluster out ?

[EleCTriCT]

Remove bezel

red dots in photo show screw locations

 

there may be 2 or so hard to see screws underneath to the left of my hand.

 

cluster has 2 screws on each side afterwards

 

i think there is 3 connectors on the back, brittle fragile connectors be careful

 

 

 

cheers

Edited December 31, 2014 by EleCTriCT