jaxsondog

the left side dash lights do not work, occasionally they come on, when I turn the truck off and turn it back on the lights do not come back on. only the left side is acting up, the right side works fine.
Another issue that my be related, the temp gauge is acting up. When I turn the key to the on position the gauge will rise to the middle of the gauge after a few moments the gauge falls to the correct position. when the truck is turned on the gauges rises with the motor temp. I just installed a new factory sending unit thinking the sending unit was failing.
HELP

wyoming9

iTrader: (1)

Just what lights are you talking about??

It sounds like you have a loose connection bulbs might be loose .

Could be some wiring has rubbed together .

Loose ground ??

What have you already checked ??

muddpigg

iTrader: (1)

Intermittent electrical issues are fun to track down. Be patient.

jaxsondog

wyoming9 thanks for the reply. i have checked the entire circuit board on the back of the gauge cluster. every circuit tones out from the plug socket to it's ending point.
The 2 lights are the 2 small 2v ? lights that light up the left side of the gauge cluster, directly to the left of the oil and temp gauge.
The lights on the right side work fine, however they are powered by a rear plug on the right side of the gauge cluster and the lights on the left are powered by a rear plug on the right side.
Im sensing that I have lost the hot somewhere in the wiring loom after it splits off and goes in each direction. Im assuming the hot comes out of the reastat and somewhere up that line I've lost the hot. I don't think the ground is an issue as everything else works fine off the same ground circuit.
Any input would be greatly appreciated.

RAD4Runner

A multi-meter will eliminate the guesswork. If no multi-meter, Harbor Freight is your friend.

wyoming9

iTrader: (1)

The Rheostat completes the circuit by allowing it to go to ground .

So we are both on the same page the 2 lights in question provide the back light for the gauge cluster.

You have tried just replacing the bulbs with new ones.


Know that corroded connections do tend to ring out with the meter probes but not when things are put back together. It can drive you nuts .

Did you see and damage to the traces

These vehicles are getting older .

I would guess your problem is in the blub socket connection or one of the other connections as the truck moves and shifts it causes the connection to open and close at random.

Have these lights ever worked ??

Did you add some electrical device where you were cutting and splicing a light circuit??

jaxsondog

Wyoming You and i think alike. to answer your questions.
the bulbs are good. they tested and Im able to get them to light up.
all traces are good. no corrosion no excessive dust/dirt
yes these lights work occasionally.
Bulb sockets. some time the trace can rip and tear directly under the bulb contacts. I checked for that The bulb sockets are good and the bulb contacts are firmly seated into the trace.
No new circuits or taps into any light or hot circuit.
I feel pretty confident that the gauge cluster is all OK.
I think im getting some sort of short or cross over between the temp sending wire and these lights. any chance of that?
The temp gauge occasionally works perfect however most of the time the temp needle rides right in the middle of the gauge even when the truck is cold. Occasionally when the key is in the on position, motor not runnig the needle will rise to the middle of the gauge and after a short period the needle will fall to the bottom of the gauge.?
The common issue here is that the temp sending wire and the hot wires for these lights are in the same gauge plug. ??? I've now chaced these wires back to the main wiring loom, all is OK

wyoming9

iTrader: (1)

Looking at the plug do you see any signs that the two wires could possibly be touching each other .

Only if the temp sending unit wire is grounding through the light circuit will it cause the needle to move.

As all these sending units allow the circuit to ground changing resistance as the temperature changes .

Back to my question has there been a time when these lights worked with no issues??

jaxsondog

wyoming
all contacts in both the male and female sockets are good. no indications that hey crossed.
I'm thinking there is a short in the wiring loom as the plugs and contacts are all good. Is there a chance the temp gauge itself is bad? I think I'll run a new wire from the sending unit to the gauge and see if the sending wire is bad.
Regardng the lights. would it be safe to jumper from the light circuit on the right side over to the left. This would allow the lights to operate with the switch and rheostat? I would eliminate the hot from the plug on the left so the power can not go backwards and possibly short out?
Im thinking this would bay pass any short down line whether it be in the wiring loom or ???

Yes, both the dash lights and temp gauge worked fine for many years. However I don't drive the truck often or at night, so I can't determine when the issues started.
I have not added any new electrical of any kind in over 7yrs

jaxsondog

woyming9
Got it.
The temp gauge sending wire has a short somewhere. replaced the wire and all is good.
The gauge lights. in the end it was the bulbs. The filament was not burned it was cleanly broken. So there were times the broken filament coil would catch the opposite broken side and it would light that's why it would test.
I found the broken filament using a jewelers loop that magnifies 20X.
Thanks for the input.