dash lights not coming on

[danielsan]

ok i searched all the posts start the same but no one give a clear answer or the post just dies.

i have checked:fuses= oktcu= ok (everything looks fine inside, even the glove box light works)wiring= i looked at the diagrams, checked voltage and it was fine also the grounds are fine. used a digital multi meter

few questions. i read the if the tcu is bad then also the glove box light would not work.. is this correct??

also if the cluster has a bad ground then the hvac lights will not work either???

how do you test the dimmer switch?? im getting power to the switch, twelve volts across all wires.

i also tried to ground the red with yellow stripe wire but still no lights.

hvac no work, cluster lights no work. i have power going where it should from ign. batt. and illumination wires. grounds seem to check out. so i am lost.

[danielsan]

also noticed since i fixed the fuse being loose (audio 10amp) the light for clock comes on when i turn the key to acc or on but shuts off when i turn the lights on. now the lights for the fan control and temp dont light on the hvac do not light up.

[low91240sx]

Sounds like you have a loose connection somewhere but have you made sure that the bulbs arn't just simply blown? seems idiotic but seriously I'd check em just to be able to check it off of the list

[modulation]

If you have a copy of the FSM then do the test for the TCU in there.

How many volts are you measuring with your volt-ohm-meter at the connection to the instrument cluster?Measure between the power wire and frame, then power wire and black wire it should be using as ground.

Do your tail lights work?

Your problems sound similar to mine. I had a burned out TCU. Thought I fixed it by resoldering a trace but when I check I was only getting 6v to the insturment cluster. I followed the diag procedures in the FSM for the TCU. You really don't troubleshoot the tcu you just prove it isn't anything else and then replace the TCU.

I replaced my TCU and it worked, I guess I burned out a trace or something on the actual microchip that control the dimming.

[danielsan]

tail lights work fine so its not a fuse. also followed the test procedure for testing the tcu. though i noticed that my plug has one less wire then pictured in the FSM so i couldnt test the tcu on the last step.

now that i think about it i think there is a red/blue wire that is making a ground at the stereo harness (last owner cut it up). i think the red/blue are supposed to have + voltage. i cant believe i didnt think about that. but i have to double check if it was that wire.

im thinking it might be a ground. also if one bulb goes out does that interrupt the current flow??? i checked a few bulbs on the cluster and they seemed fine.

[modulation]

tail lights work fine so its not a fuse. also followed the test procedure for testing the tcu. though i noticed that my plug has one less wire then pictured in the FSM so i couldnt test the tcu on the last step.

Make sure you are looking at the harness the right way. When they show the harness plugged in the TCU in the manual you are looking at the back of the connector not the front.

Quote »now that i think about it i think there is a red/blue wire that is making a ground at the stereo harness (last owner cut it up). i think the red/blue are supposed to have + voltage. i cant believe i didnt think about that. but i have to double check if it was that wire.[/quote]That shouldn't matter. I didn't have any of my radio wires connected and I still had working dash lights.

Quote »im thinking it might be a ground. also if one bulb goes out does that interrupt the current flow??? i checked a few bulbs on the cluster and they seemed fine.[/quote]No one bulb doesn't matter. I had a few out when I got my cluster from a junk yard but the cluster still lit up.

Did you check to see how many volts you are getting at the harness you plug into the cluster on the pin for the lights?

[danielsan]

well i got it to work. i was getting continuity through all the grounds which are the black wires using my multimeter. i grounded the cluster directly to the chassis via the screw that grounds the digi speedo. unless there is another wire of different color that is also a ground? but you know whats strange? if i check continuity between the harness ground and the circuit board while the harness is connected to the cluster i get a signal from the multimeter. hell i was even getting 12 volts to the bulbs yet no lights.

if anyone knows any other grounds other the black wires let me know.

thanks.

[89TN240]

i also have the same problem and i cant figure this out i have tried 4 almost a year now off and on. i have tried everything anyone has said and nothing

[xxmexx]

Just replace the TCU (the little white box next to the drivers side fuse panel.) Its as simple as unplugging it and removing 1 screw. My dash lights went out sometime back and this fixed the problem. I got my TCU and 2 spare ones from a junk yard for $20 becuase they have no clue what it is.