Wiring dimmer

[vacuum 6]

My dash lights will not turn on. It looks like the dimmer is bad and/or the wiring. Within the dash the dimmer switch plug has a fours wires...green, black, brown, and white. What should I see at each terminal with the headlight switch on then off?

 

[vacuum 6]

INST LPS (5 amp) & GAUGES (20 amp) fuses are fine.

 

[salvageV6]

BLK is ground for the courtesy lamp switch feed.

White is output of the courtesy lamp switch feature grounded when the switch is rolled up and ON.

Dark Green is the +12 feed from the 5A INST/LPS fuse.

Brown is the variable voltage output to feed the lamps, should vary but go to +12 when the dimmer is set to the bright dash light position.

 

[vacuum 6]

BLK is ground for the courtesy lamp switch feed.

White is output of the courtesy lamp switch feature grounded when the switch is rolled up and ON.

Dark Green is the +12 feed from the 5A INST/LPS fuse.

Brown is the variable voltage output to feed the lamps, should vary but go to +12 when the dimmer is set to the bright dash light position.

BLK and white are ground.

With a multimeter I should get +12 at the dark green. Run +12 to the brown to verify the dash lights. Right?

 

[salvageV6]

White should be the dome lamps ground side lead which will read +12 through the elements to the power feed if the switch isn't on. It will go to ground with the switch in the on position and light up the dome light.

I had the feed backwards on the dimmer, read it wrong sorry.

The Brown is +12 out of the headlamp parking light circuit.

Should read +12 with the parking lights on, or headlights on.

Dark Green will vary in voltage but be +12 with the dimmer on HIGH, this in turn feeds the 5A INST/LPS fuse.

Sorry about the confusion.

Dark green is the output to the fuse then the lamps, gray wires in the dash for all the lamp circuits or you can take a voltage reading on the LPS socket terminals there which is the output also of the 5A fuse.

 

[vacuum 6]

White should be the dome lamps ground side lead which will read +12 through the elements to the power feed if the switch isn't on. It will go to ground with the switch in the on position and light up the dome light.

I had the feed backwards on the dimmer, read it wrong sorry.

The Brown is +12 out of the headlamp parking light circuit.

Should read +12 with the parking lights on, or headlights on.

Dark Green will vary in voltage but be +12 with the dimmer on HIGH, this in turn feeds the 5A INST/LPS fuse.

Sorry about the confusion.

Dark green is the output to the fuse then the lamps, gray wires in the dash for all the lamp circuits or you can take a voltage reading on the LPS socket terminals there which is the output also of the 5A fuse.

Making sure I understand...

White is the dome ground and black is the dash light ground. Right?

Brown is +12 with the headlight or parking lights on. Right?

Green is the output from the 5A fuse and should read +12 at the terminal (assuming the fuse is good)?

If I run +12 to the gray wire (dash lamp circuit) then the lights should illuminate. Where's the gray wire?

 

[salvageV6]

The black wire goes directly to ground, attached to nothing else with the switch OFF.

When you click the roller switch to turn ON the dome lamps, it puts the ground connection out to the white wire which goes to the dome lamp circuit.

That circuitry and wiring has absolutely nothing to do with dash lamps however it is a separate switch part of the roller.

The brown will be at +12 with the headlights and parking lights ON.

Green is only the output of the dimmer control and goes down to the fuse panel and feeds the 5A INST/LPS fuse there.

There are two fuses for the dome lamps, the parking lamps 20A fuse and then through the headlamp switch then through the dimmer, then through the 5A fuse out to the lamps on the gray wires in the dash.

If you get +12 on the brown wire the 20A parking lamps fuse is good if not check that one.

If the dark green wire has +12 with the dimmer on HIGH then check the LPS terminal in the fuse panel and check the 5A fuse there.

If you wish to check the lamps in the dash I would use a 5A fused wire to the battery and pull the 5A fuse in the fuse panel.

Try putting the 5A fused external wire to the LPS terminal in the fuse panel to check the lighting.

PULL THAT 5A FUSE FIRST so you don't backfeed any other circuits if there is a short somewhere or problem with that wiring.

Gray wires are out of the fuse panel after the 5A fuse, and run throughout the dash area to illuminate various bulbs such as shifter, dash lamps, ashtry lights, radio day/night lighting etc.

 

[vacuum 6]

The black wire goes directly to ground, attached to nothing else with the switch OFF.

When you click the roller switch to turn ON the dome lamps, it puts the ground connection out to the white wire which goes to the dome lamp circuit.

That circuitry and wiring has absolutely nothing to do with dash lamps however it is a separate switch part of the roller.

The brown will be at +12 with the headlights and parking lights ON.

Green is only the output of the dimmer control and goes down to the fuse panel and feeds the 5A INST/LPS fuse there.

There are two fuses for the dome lamps, the parking lamps 20A fuse and then through the headlamp switch then through the dimmer, then through the 5A fuse out to the lamps on the gray wires in the dash.

If you get +12 on the brown wire the 20A parking lamps fuse is good if not check that one.

If the dark green wire has +12 with the dimmer on HIGH then check the LPS terminal in the fuse panel and check the 5A fuse there.

If you wish to check the lamps in the dash I would use a 5A fused wire to the battery and pull the 5A fuse in the fuse panel.

Try putting the 5A fused external wire to the LPS terminal in the fuse panel to check the lighting.

PULL THAT 5A FUSE FIRST so you don't backfeed any other circuits if there is a short somewhere or problem with that wiring.

Gray wires are out of the fuse panel after the 5A fuse, and run throughout the dash area to illuminate various bulbs such as shifter, dash lamps, ashtry lights, radio day/night lighting etc.

I think its easier in a drawing...see below. Correct?

Both fuses are good. I'm not seeing +12 at the brown. My headlight switch works less the parking lights.

 

[salvageV6]

If none of the parking lamps work then the headlight switch is probably bad, the brown wires out of the headlamp switch runs a lot of parking lamps.

The feed for those lamps is off the same fusible link as the headlamps, so if they work that isn't melted.

However the feed goes through the 20A taillamps fuse first and then out on the orange wire to the headlamp switch.

Make sure you have power on the orange wire to the headlamps switch and power out on the brown wire when it's ON at at that switch for the parking lamps.

Problem appears to be way "upstream" from the dash lamps dimmer and fuse.

You should have mentioned you had no parking lamps in the first post.

 

[salvageV6]

Make sure you check that 20A Tail Lamps fuse it's next to the radio fuse in the middle of the fuse panel.

Gauges fuse has nothing to do with this wiring.

TAIL LAMPS fuse 20A feeds the tail lamps out of the headlamp switch, and then the dash lamps, via the dimmer, and the 5A INST/LPS fuse.

 

[vacuum 6]

Yeah, I wish I would have posted the parking lights dont work from the start but just found out. Thanks for the 411, I'll post something tomorrow.

 

[vacuum 6]

Make sure you check that 20A Tail Lamps fuse it's next to the radio fuse in the middle of the fuse panel.

That what it was...tail lamp fuse. Thanks!

For future use, do you have the wiring schematic you can email me?