TT.Mk1 Fog Light Switch Mod

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Back to 2000-2005 (Mk1)

Submitted and Entered by: MCPaudiTT

With this mod, you will be able to turn on the Fog Lights WITHOUT turning on the Headlights. This is accomplished by soldering the fog light contactor to the "On" position, so that any time the switch is pulled (available only in the parking and headlight modes of the switch) the Fog Lights come on. Normally, the Fog Lights will NOT illuminate in the Parking Light position of the switch.

1 Housing Retention Pins Extended

The black nib at the top of the housing is what keeps the switch panel in the car.

2 Housing Retention Pins Retracted

If you push in the headlight switch, and rotate it 1/2 way to the parking light position, you can see the nib retracts. This is how you pull out the switch panel housing.

3 Switch in Retracted Position

This is a shot of the switch in the retracted position, note the rotary position here, and the pushed position in the next shot.

4 Switch in Retracted Position

See! It's pushed in!

5 Pop off at the four divits in the housing

Removing the switch from the panel is rather easy (fingernail is good enough). There are four spots that need to be popped off - each has an indent like the one you see here. I could open the sleeve off the housing with a fingernail enough to pull the switch out.

6 Guts and switch

Here are the switch guts, next to the switch face.

7 Pop up the four tabs and push out the guts

Taking the switch apart is a little trickier. You need to bend out two tabs on each face, and push out the switch insides from the housing. Note that from the connector end, just the blades move out, not the whole black surface.

8 Guts on the way out

Here the guts are coming out of the internal housing.

9 the guts

Here are the guts. The fingers you see are the electrical contacts that transfer the lighting signals. As has been explained by TTakes2, the switch acts like a music box, as you turn the switch, different combinations of the fingers make contact.

10 Bottom, Off

This is the off position. you can see the leftmost finger is making contact, the next three are not, and the fifth is. The fourth contact is the one that removes power from the foglight switch when not in the Headlight On position. The two contacts at the far right (#6 and 7) are the foglight and ??? (I think it is the Euro-Rear-Foglight, which in not ever engaged on an NA switch housing).

11 Bottom, Parking Lights

Here is the parking light position. Only the third contact is in place (#2 and 4 have lifted).

12 Bottom, Headlights

Here is the Headlight On position. Contact #3 has lifted, and #2 and 4 have contacted.

13 Bottom, Headlights AND Foglights

This is the Headlight position, with the foglights on. Note that only the #6 contactor has moved.

14 Top, Off

Here are the top connectors. This is the Off position. Here, only the first contator is engaged.

15 Top, Parking Lights

In the parking light position, the first four fingers engage.

16 Top, Headlights

Headlights brings on the sixth contactor. The fifth never comes on. Again, could be the Euro-Fog.

17 A dab 'o solder

I chose to solder the #4 bottom finger to the switch contact, instead of inserting the copper piece as TTakes2 did.

18 Attach solder to lever

First I put solder a ball to the face of the contactor. I also cleaned off the contactor pad - there was a carbon build-up that the solder would not stick to.

19 Contact!

Now that puppy won't lift!

20 Solder lever to contact (needs a ton of heat!)

I cranked up my iron to 700F, and it took several seconds to heat the finger enough to melt the solder below. This joint could well fail due to a cold solder joint, since the lower contact never really gets hot enough, but it is sticking right now. Resoldering is pretty easy too, so it is not too big a deal

21 Off

Here we go again. This is the off position. Used to be finger four was lifted here, now it is not.

22 Parking Lights

Parking Position. Used to be #3 was the only one contacting. Now #4 is, and the Fogs WILL come on if you pull the switch.

23 Headlights

The Headlight position looks just like it used to.

24 Buttoning Up

Since I had the guts in position, I just slid the cover back on the back.

25 Slide it home

Push it home, and you are good to go.

26 All assembled

Everything looks normal up front.

27 Plugged in

Put the electricals back in to place.

28 Foglight Indicator at Parking Light position

What's This?! The vertical position is the Parking Lights position, but as you can see, the green Fog Light indicator is illuminated - is this some kind of prank?! Let's go up front and check...

29 Fogs with no heads

Nope, no prank. The fogs are on, without head lights, and the parking lights are on. Just as we wanted!

Back to 2000-2005 (Mk1)