wickyc

My gauge lights in my 83 have stopped functioning. They work mechanicly but just no lights. Every other light in my car works, even the idiot lights. Ive taken out the cluster and checked every connection with my multimeter, and am gettin a power reading of around 12v. I even checked the dimmer, and every bulb and fuse in the car also. All in all about 3 hours of work and still nothing.

I would greatly appreciate any opionions on what could be the problem.

Bob Holton

Ground?????

lovintha7

Got the same problem man. I think it's got something to do with the wires that run from the dimmer switch to the back of the radio somewhere.

BUMBLEBEE7

iTrader: (1)

check dimmer, been there.

Rx-7Doctor

iTrader: (13)

Check the fusable link in the engine compartment, believe it is the center one that
may control power. Also did you try bypassing the dimmer switch? If no power goes thru the dimmer the instrument lights will not work. rx7doctor

Misthael

My dimmer has never worked, but all my lights still work. I did hook a cd player wrong once and fry teh wire that lit up my guages. Had to take the dash apart and replace the melted part of the wire. That was a crap job. I'd like to just tear out all the electrical and do it right since the engineers back then didn't seem to do such a wonderful job of building our cars for servicing.

Kamy

I just got done yanking my dash tracking down the same issue. The wiring harness behind the radio could be a suspect for bad ground if someone has done a poor aftermarket radio install (like I am dealing with). I think my problem is somewhere behind the dash cluster due to the amount of corrosion I found there, so tomorrow I'll start pulling out the harnesses there looking for issues (if it's not raining).

This car sat under a tree for seven years, had some pest investations, ants, wasps... but I recently found some evidence of mice too, sure hope they didn't chew through anything important.

RX7Doctor, where exactly is this fusible link you mentioned firewall/right side/leftside?

trochoid

iTrader: (6)

Non working dash lights are most likely a fubared dimmer switch. If the roller **** rolls more than 180*, it is toast. Over rotating the **** breaks the wires in the switch.

I have 4 of them, 1 works, and I still need 2 more for the other cars.

Kamy

That sure would be a poor design characteristic wouldn't it? Doesn't the switch have some sort of stops in it to prevent over rotation?

What about having a switch rebuilt at an electronics shop? Shouldn't cost too much, I would think, it's a pretty simple circuit.

trochoid

iTrader: (6)

I took one apart once, bought it on eBay, got hosed. The stops seem to be easily over ran and when that happens, the fine wires inside shear. Didn't look that easy to repair, but electrical is not my forte.

My Chevy van has a similiar switch, much stouter though.

Kamy

hmmm, I've got two, one is really suspect, maybe I'll pull it apart and have a look. I know some eletronics types who could probably take a look at it. I'll let you know what it takes to rebuild it if possible.

Rx-7Doctor

iTrader: (13)

Trochoid, the switch you are refeering to is the 84-85. This one is located on the left portion of the underdash and rolls top to bottom. The one Kamy has is for 81-83 which is located on the right side of the under dash and turns clockwise/counter clockwise.
Kamy, the fuseable link i am referring to is located on the left fenderwell area and is the center of the 3 that are there, just swap with one of the others and see if the lights work. If not then it's probably the dimmer switch or wiring. To check the dimmer switch just bypass it.
Unplug the switch from the harness and insert a jumper to the 2 multicolored wires
this applies direct power to the instrument lights. Do not try to splice the terminals to the switch and then bypass or you will fry wires. It takes about 2 minutes to bypass. rx7doctor

Kamy

RX7Doctor, already tried jumping from the RL to the RG lines, all that does for me is blow a fuse, apparently the PO thought putting a 15 amp fuse in place would fix it because that's what I first found burned out there. I'll give the fusible link a look in the morning.

It's a real mess behind the dash, lot's of surface rust, some verticle surfaces are covered, and it looks even worse all the way to the left side where the harnesses all come together before passing through the firewall. I'm gonna start pulling it out carefully and inspecting it tomorrow.

No big loss though, the old dash had a couple of cracks in it, maybe I can find a replacement before it's time to go back together (if I can get it all back together that is )

All in all, I'm having a great time with it though and this is going to be my son's driver, as soon as it's road worthy I'm getting another for myself to get my manual transmission yah yah's out. I was forced into buying a Mazda6 with an A/T cause the wife can't/won't drive a stick.

AND, I guess I got bit by the bug while deciding over this one for my son!

wickyc

Will try some of this stuff today. Thanks for all the help guys.