Tachometer doesn't work in 92 300ZX

Aug 29th, 2002, 10:50 PM

I bought this car and the tach wasn't working. I took the dash apart and it's all electric....no cables. I have the huge manual for the 92 300ZX. I've looked through the schematics and I don't really want to go through and troubleshoot the system.

I still can't seem to find a fuse for the tach. I'm hoping it's something simple like a fuse or a relay.

Anyone have any quick ideas on what it could be or anything I should check out?

I could take it to the dealership but I have a feeling they're gonna want to charge me $60+/hr labor to troubleshoot and fix the system. And I know they probably can't quote me the time it will take since they don't know exactly what is wrong with it.

What do you think?

I was going to autox the car this weekend....but I'd prefer to have the tach working.

Aspen_2.5RS
Cam

Middy · Aug 30th, 2002, 04:09 PM

Check the tach needle pin. The pin could be positioned wrong and preventing the needle from swinging properly. I don't know how this could happen if the gauges were never tampered with, though. Here's a link to a procedure for checking/fixing the pin position.
http://www.twinturbo.net/cgi-bin/ttn...&msg_id=725955

If it's anything else.... you got me.

Aug 30th, 2002, 10:20 PM

Middy,

Thanks. I don't think the actual plastic has ever been removed from the front of the gauges. So I don't know.

I talked to a local repair shop guy today. He said he wouldn't charge me an hourly fee. He also said that he wouldn't charge me anything if he couldn't fix it.

I just don't wanna pay a ton of money.

I leave it with them Wednesday morning. I'll post the result.

Thanks.

Aspen_2.5RS
Cam

Sep 7th, 2002, 01:02 AM

I decided not to take it to that particular mechanic.....he's kind of a shiester (they almost all are around here). But I'm going to take it to another guy that is farther away Monday morning.

I'll post the result.

Cam

Sep 11th, 2002, 09:44 PM

I took it to the trusted mechanic and he said I'd be better off taking it to the nissan place. He really didn't want to work on it and didn't have the knowledge. If it was a distributor equipped car he would have worked on it.

Anyone have any other ideas of what I should look for? Is this a common problem on 300zx's?

Cam

terry dibler · Oct 3rd, 2002, 08:06 PM

i have the same problem with my 95 maxima with the same engine still cant find any help on that problem

Oct 3rd, 2002, 09:02 PM

I ended up talking to a Nissan tech at the dealership and he circled for me which wires I need to check using something that will measure r'spm (like a fluke meter). He also was about 90% sure that it was the tachometer unit itself that was bad.

So out of curiousity we checked on how much just a new tach unit would be....$270!!! Um, screw that. So, I guess I'm going to try to look in the junkyards and try swapping in another tach unit. If it doesn't work then I'll just take it back.

Please post here if you figure out what is wrong with yours first. Thanks.

Cam

Oct 21st, 2002, 10:20 AM

can you be a little more discriptive of your problem. is the needle jumping around? or is it dead as can be and not moving? if the needls is jumping around all over the place it most likely is the connection. but i have a 1991 so it may be different. but there are a few connectors that plug into the dials, use some di-electric greese after you clean the connectors really good. that worked for me. not very fun pulling them out though.

Oct 21st, 2002, 01:27 PM

I'll probably pull it back out again and make sure those 3 screws on the back are tight. And also recheck to make sure there are no burn marks on the printed circuit.

The needle just sits there at 0. One time, and only time, I've seen it move with the revs. That was right after we put a new clutch in it. We stopped to trade drivers and and my friend said ..."look!". Then it went back to zero again and hasn't moved since.

Cam