knussear

Hi List

I have a 1982 928 Coupe

I'm trying to diagnose a dead tachometer, and cant for the life of me translate the wiring diagram in the manual to the one I should check going to the connectors in the pod. I read elsewhere that on one model it was pin 3 of the center connection to the edge connectors. I can see two connectors on mine though, and wondered if earlier models only had two, or if I'm just not looking hard enough.

Checked all fuses already etc, and no problems there.

Thanks

Ken

knussear

Update - I did figure out that the signal is supposed to come from a green wire on the G7 plug in the main panel. Checking that wire gives me ~ 6 V when the car is running and switching my volt meter to AC I get an increasing AC voltage reading with current. I'm assuming this means I have a good tach signal there. The two connectors that I can see are on the bottom left and right of the pod. I can access both of them, attach and detach and they are snug. I can see an additional five or six wires including a green one that appear to attach somewhere higher up in the pod. Not sure where to look for the middle connector. My diagram definitely indicates 2M as a green wire. I also see some L's and R's along with other M's so I guess this connector must be the one I need.

robot808

Ken, I don't have the diagram where I am at, but I do know there is a third connector on the 82's (and all MY's I believe). It connects to the back, near the middle. I don't think you can get to it without pulling the whole cluster out. The problem may very well be on the foil on the back of the instrument cluster.
If you have never pulled the pod off before, it's not that bad a job. The WSM covers it well. There alot of good threads on how to clean the connections on the back.
Good luck with this.

stolarzj

I just fixed a tach in a 82, the issue was in one of the circuit traces on the pod. Trace each circuit for the tach, it should be all the nuts on the backside of the tach, check for continuity from the nut to starting point on the pod connections.

knussear

OK, Found a 15 minute pod removal thread. I'll run it down this weekend. Thanks for the help.

Ken

Z

The connector contacts are numbered starting with #1 at the top in the picture.
Contact #1 - Ground
Contact #2 - RPM signal
Contact #3 - +12v

stolarzj

The one I fixed had a break in the signal trace right after the nut.

Maleficio

I got lucky. Around eight or nine screws were completely backed out. I ran them all in, tach works great now. I'm not sure how anything in the cluster was working with so many screws backed out.

PO paid a shop (European Autoworks, Va Beach, VA) a grand to go in and replace the light bulbs. It looks like they saw him coming and tried to set themselves up for more business by unscrewing all the terminal screws.

Didn't cost me a dime to fix their bull****.

Looks like they over-filled the auto-tranny, too. Wow, talk about sabotage. ???