Dashboard Light Dimmer Switch Smoking

NOLAHusker

Member
Joined
Jul 16, 2014
Location
New Orleans, LA
TDI
2003 Jetta Wagon TDI
2003 Jetta Wagon

Well, I had a bit of a scare on my drive home this morning. The dashboard light dimmer switch started smoking as I was driving down the highway. I figured out to turn off the headlights, and that killed the smoking, but I obviously can't drive this thing at night any more.

My question, of course, is what should I do about this? It seems as if the obvious solution for this is to change out the switch. I just want to make sure I don't need to check anything else.

Thanks!
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
Change the switch for an immediate fix.

Look for a headlight relay kit if you want a permanent fix. They are fairly inexpensive. What the relay setup does is route the high current power for the headlights through the relay rather than through the headlight switch. The result is brighter headlights since the power no longer needs to go on a circular route through all the connectors and cabin wiring back to the engine bay, plus the headlight switch will never wear out again since it doesn't have to work very hard.
 

NOLAHusker

Member
Joined
Jul 16, 2014
Location
New Orleans, LA
TDI
2003 Jetta Wagon TDI
Thanks. Changed out the switch this morning and there seem to be no issues. Given that it had 201,000 miles on it, I don't know if I want to invest the time and energy in installing the relay.

Appreciate the advice, though. I'll see just how much work it might be.
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
If you can find a kit it is literally as simple as plugging one of the headlight connectors in to the relay harness, plugging the harness in to the headlights and connecting the harness positive to the battery positive. Took me all of 10 minutes on my car.
 

Dimitri16V

Top Post Dawg
Joined
Jan 30, 2005
Location
DE
TDI
01 Golf, 04 Golf
the switch won't smoke , wires will. you have high resistance somewhere
 

mrGutWrench

Top Post Dawg
Joined
Aug 29, 2002
Location
Carrboro, NC
TDI
'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
It was definitely the switch smoking. The body of the switch was warped from the heat, and there are no wires adjacent to the side of the switch that could cause that.
Let's be specific here. Are you talking about the little instrument light dimmer switch (a little wheel-type dimmer), the lighting/headlight master switch (round, about 2" in diameter, with 2 little headlight icons on the top edge of it), or the headlight dimmer/turnsignal switch on the steering column?
It was my instrument light dimmer that fried (you can see burnt areas in the adjustment wheel) and smoked. That was on Wednesday night. A friend had a spare used one and I put that in and the lights still don't work. Both the 5-amp fuses are good. I don't have a good feeling about this.

'03 Jetta Wagon, TDI - ALH, 370K miles
 

mrGutWrench

Top Post Dawg
Joined
Aug 29, 2002
Location
Carrboro, NC
TDI
'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
L ... A friend had a spare used one and I put that in and the lights still don't work. Both the 5-amp fuses are good. I don't have a good feeling about this.

'03 Jetta Wagon, TDI - ALH, 370K miles
Is there a relay in this system? I have power at/through both 5-amp fuses in the fuse panel next to the driver's door but no power at the central terminal of the connector to the rheostat dimmer. Everything (taillights, brake lights, interior lights - except for the instrument lights and heater control lights, headlights, etc.) all work OK. Just no lights on speedo/odometer.
Thanks, MrG
 

cjz

Member
Joined
Dec 28, 2014
Location
Baltimore
TDI
2004 Jetta TDI
Bumping old thread . . .
I had the same issue with my MKIV Jetta.
The dimmer switch fried and instrument cluster won't light.
I ordered a new switch and just hooked it up - but lights are still out
(dash cluster, radio lights). Fuses are fine.
Tail lights and turn signals are fine.
Did you ever find the root cause?
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Was you control melted like in the thread?

You need the headlight switch on to check this.
Fuse 3 is the one for the dash & such lights, not sure if 04 is different. It's 5 amps.
Power to the dimmer control is a gray wire going to pin 2. It's gray with a blue stripe
It feeds the lights from pin 3
Pin 1 is the ground, its brown.
If you have power going out you have to follow where it's lost.
No power follow the wire to the fuse box, then from there to the headlight switch.
 

cjz

Member
Joined
Dec 28, 2014
Location
Baltimore
TDI
2004 Jetta TDI
I appreciate the response.
Yes, the control switch melted and I am still troubleshooting.
I will have to get out my multi-meter and start checking.

This happened immediately after I replaced the driver side fender liner.
I thought maybe I pinched some wires - took it off and it looked fine.
The signal light on the fender still works.
 

badgervwman

Member
Joined
Nov 14, 2018
Location
Wisconsin
TDI
[2003 Jetta] [2004 Passat]
I had the same problem last night I was just driving home then smelt something burning like plastic and I saw the dimmer switch arching and smoking inside. I had literally smoke coming out the vents. Very surprised the fuse didn't pop first, I quickly pulled into a parking lot and took out the switch. I think I might know why there's high resistance I was using the heated seats at the time when this all happened. I'll have to check the schematics I'm thinking the heated seats run on the dimmer switch side the fuse checked out good. Really hoping the power feed to the heated seats didn't short out the dimmer switch which could be a possibility.

***If you have the seat heaters on don't set them very high or the dimmer switch will ark and short out*** This really should be addressed and reviewed by VW for a TSB recall.
 
Last edited:

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
What model/year is your car badger? Haven't seen many of these failures on these forums.
 

badgervwman

Member
Joined
Nov 14, 2018
Location
Wisconsin
TDI
[2003 Jetta] [2004 Passat]
Dimmer Switch Up In Smoke

Hi BobnOH, I have a VW 2003 Jetta 1.8T GLS, the burning plastic really lingers I'll have too double check for chard wires.
 

badgervwman

Member
Joined
Nov 14, 2018
Location
Wisconsin
TDI
[2003 Jetta] [2004 Passat]
I checked the wires nothing was damaged then went to the junk yard and found a dimmer switch and everything's working good. $5 used / $40 new
 
Top