No rpms

[atownturbo]

Hi I have read my service manual a dozen times trying to find the anwser to my question so hopefull you guys can help. the other day my car died(left my lights on) and when I got my buddy to help me jump the car he put the jumper wires to the wrong leads (pos to neg) (neg to pos) now my rpm gauge does not work?

 

[BurrowZ]

Does the rest of your cluster work? If not you might have just blown a fuse if you are lucky

 

[atownturbo]

I checked all my fuses and there fine, and yes the rest of the cluster is working, I swaped it as well.

 

[2GFWDbeast]

i was told there is something called a noise filter i believe its on the firewall.

 

[9!'clipseDOHC]

You fried something, most likely a fuse or relay. I know '90's have a separate tach output but you have a '91. It could be the "transistor" discussed in this thread: http://www.dsmtuners.com/forums/newbie-forum/37213-rpm-gauge.html#post322276.

 

[19Eclipse90]

The noise filter referenced in that thread is a 1990 only item as far as I know. OP, you swapped clusters and the tachometer didn't work on either of them? Just to rule out possibilities, were they both '91+ clusters?

 

[atownturbo]

No one it is a 90 cluster

 

[19Eclipse90]

A '90 tachometer doesn't work in a '91+ car without the tachometer gate (see post #9 in second link for visual) that is originally wired into the 1990 coil pack. The problem may be as simple as the tachometer going bad.
http://www.dsmtuners.com/forums/appearance-interior-exterior/385540-tach-problems.html#post152372759
http://www.dsmtuners.com/forums/newbie-forum/386851-help-tach.html#post152392380

The tachometer signal runs from the white wire on the power transistor unit to the ECU (pin 109) and to the tachometer. First thing is first, is there a check engine light on? If so, read the code. It is possible that the ECU is not receiving a signal at that pin, meaning the tachometer is also not receiving a signal: http://www.dsmtuners.com/forums/newbie-forum/249943-rpm-tach-problems.html#post151100488

You've probably noticed wiseman steve knows a bit about these issues, so I would look into doing what he suggests in this post using an automotive meter that reads RPM and trace the signal back to the ECU if necessary: http://www.dsmtuners.com/forums/bolt-tech/388781-90-tach-problems-getting-angry.html#post152419806.

 

[atownturbo]

Thanks ill check this stuff out