Ok here's the story... i put in a radio a while back and my gauge and hvac lights didnt' work after that. tried to figure out what was wrong and found that if i grounded the orange ill. wire they would work but the dimmer didnt' work. well i got rid of that radio and put the stock back in and figured they would work but they don't still. i've cheked every fuse in the car and they're all good. anybody got any ideas on what else it might be? maybe a relay or something???

Did you check the fuses underneath the hood?

Any of the interior lights that can be dimmed share a common feature that confuses many people. These light do not change brightness due to the positive voltage feeding them being adjusted up and down.

Instead, these lights have the full voltage going to them anytime the marker lights are turned on. Then the lights are then dimmed by the controller varying the amount of "ground" they are getting.

This is why when you grounded the "illum" wire the lights came on at full brighness but would not adjust up or down. You were accidentally bypassing the dimming circuit and supplying a full ground and thus full brighness. You must have an interuption in the circuit somewhere between the lights and the dimming circuit to be causing that problem.

Are there any lights in the illumination circuit working normal right now or is everything dark, including the cig. outlet and the ash tray light?

the light in the compartment next to the cup holder works. cig. lighter light doesn't work and glove box light works. it's just the gauges and the hvac lights. any ideas?

and yes i cheked the fuses underneath the hood

As I said, it can't be a fuse if some of the lights are on or if the lights worked when you grounded the "illum" wire. You also would not have any marker lights, license plate lights, etc. if the 15A (#5)fuse were out since one fuse feeds all of those circuits.

I did make one error. The ash tray lamp is fed by the same circuit as the gauge lights BUT it is not a dimming lamp so if it is working that doesn't help narrow the search much.

Please be more specific on what is working. I also have no idea what model you have RS? GS? etc. so some of these may not apply

Do any lights work and dim properly using the dimmer knob?
--A/C switch "snowflake" lamp?
--Power mirror switch lamp?
--Fog light switch lamp?
--Defogger switch lamp?
--Rear wiper switch lamp?
--Cruise control switch lamp?
--Hazard switch lamp?

If all of these are out then it looks suspicious that the rheostat (dimmer circuit) is unplugged or malfunctioning.

I have a 97 GSX the hazard button light works when turned on and the green light on the Defog button works when turned on. the only lights that don't come on are the actuall gauge light that illuminate the gauges and the lights or LED that illuminate the HVAC controls. All the door ajar, check engine, SRS, etc. work fine. Also when i turn on my lights the backlight on the radio dims as it should. i hope that helps i really have no clue when it comes to electrical. Thanks for the help.

You descriptions aren't helping much since you don't specifically tell me if there are any illumination lamps in the car that actually change brightness when you turn the dimmer knob. If you say a lamp works I am not sure if you mean it is "on" or "on and dimming properly". It makes a big difference to know this.

So let me ask this since I'm still not sure. Other than the radio backlight you mentioned, is there at least one other illumination lamp in the car that will slowly change brightness up and down when you turn the dimmer knob?

I can have you check a few specific wires once I know if the dimmer circuit is functioning proberly for at least one bulb out of the 20 or so bulbs in that circuit.

None of the lights dim except for the raido backlight all the others don't do anything when you turn the dim knob

Okay. Let's test the dimmer circuit. You'll need to remove the driver's knee panel and reach up under the dash to unplug the connector on the back of the dimmer knob. It is a small 3-wire white plug. The lock tab you'll need to press is on the top side of the connector. Remove the connector and let the socket dangle so you can do the following checks.

Assuming you have a VOM or a test light, check the following by probing with a wire into the connector. If you are looking at the connector end with the lock tab on top, the sockets are numbered 1-4 left-to-right(Note: Position #4 is empty on the right).

#1 position on the connector is a green/white wire and it should show full battery voltage (12-13V) when the marker lights are turned on.

#2 position is all black wire and should show ground at all times.

#3 position is black/yellow and since the connector is unplugged for this test, it should show about a volt or two less than the #1 wire when the marker lights are turned on.

Assuming these all check out, the easiest test to do after this is to take a piece of wire or paperclip and connect across the #2 and #3 positions on the connector. This will supply a ground the black/yellow wire and should light up all the dimmable interior gauges and controls at full brightness.

If everything lights up when you jumper across wires #2 and #3 then I would suspect a problem in the dimmer control. If the test does not light anything up then we have more wires to test.

Try these items and let me know what you find.

alright i'll do these test soon and get back with you. i don't have a computer right now so it's sort of hard for me to check this. but yeah i'll let you know soon. thanks again for the help

Sorry to resurrect this post, but where were you trying to go with this Dave? I was playing around with the dimmer switch today and I seem to have damaged something in the wiring. I had the board out of the housing because I assumed that it was a rheostat on the positive side and not the ground. While probing, the rheostat came out of the wiring harness. Whenever I went to plug it back in i was not paying attention and had the harness backwards. I heard a light pop like a fuse blowing, but have not been able to find anything blown.

I tried a 95 dash rheostat that I had laying around and neither works. I'm about to go see if I have power coming to the switch now. I will also try jumping the two pins off you recommended. Thanks.

Nevermind I got it. I'm an idiot. I somehow missed seeing a fuse was blown after pulling it twice. Shiny things distract me too easily.