DRL Issue

[VWJETS]

I'm trying to figure out what's going on with my 1990.5 TD Jetta.
I think it is wired differently from everything else described on this forum.

Here's why...

(Keep in mind that the light switch is always in the "off" position.)

When I turn the ignition on, only the side markers/parking lights come on.

When I start the engine and the Alternator light shuts off, my headlights come on. (Probably a feature that allows the battery some extra life so that the headlights and glow-plugs don't run at the same time)

With the engine running and all the lights on, I remove/unplug the headlight switch from the dash, and the side markers/parking light turn off, BUT THE HEADLIGHTS STAY ON.

How do I modify the system so that all the lights are off when the switch is off.

I'd like the parking lights come on on the first indent/click.

Then I'd like all the lights come on on the second indent/click.

I'm guessing that one of the wires on the swich controls the parking lights, and a relay controls the headlights.

Please confirm this for me before I start messing around with my car.

(P.S. This is not to make the car look cool or for "cosmetic" purposes. This is for not lighting up my neighbour's house if I'm leaving my house late at night or early in the morning.)

Modified by VWJETS at 9:18 AM 2-15-2006

[A2B4guy]

This is a lot like the 90 Canadian Passat. It also has a 3-position headlight switch. The parking light circuit 58 is ON when the switch is in the OFF position, so the parking lights and dash lights all come on with the ignition. It has a TFL pin like later DRL switches, but it is not connected to anything. You would have to replace the switch with one from a non-DRL Mk 2.

The daytime headlights are operated by a DRL relay that is located behind the headlight switch, bundled into the harness I believe. It is turned on by power directly from the load reduction relay, and that same power from terminal X is sent to the low beam headlights through a series resistance wire. The headlight switch is not involved at all. What puzzles me is that you say the headlights do not come on when you turn the key on, until after the engine is started. There may be a wiring difference there. To defeat the DRL on the headlights, you would have to locate and unplug the DRL relay.

Unplug the relay and get a non-DRL or a US headlight switch. The load reduction relay drops out the lights, radio, heater etc while the starter is operating. I just wonder if there's a problem with that relay or the ignition switch since the headlights are not coming on right away with the ignition. The Bentley schematic would hold the key to that. BTW the Passat's DRL wiring changed in mid-91 to delete the DRL relay and use the TFL pin on a 2-position switch.

[VWJETS]

Thanks for the feedback. My concern is that the DRL relay might be a multi-purpose relay that may disable more than just my DRL system.

If I follow your description correctly, my light switch does nothing for the headlights with respect to the DRL system.

If I change the switch to a non-DRL switch, then my parking lights will not turn on, but my headlights will still turn on. The relay will shut-off my headlights. Maybe the relay will also shut off my parking light.

I think the trial-and-error approach will help me out here. I will post results.

There's probably a unique wiring method that was used for the Turbo Diesels.

[A2B4guy]

If the 1990 Canadian Passat is the same in this regard as the 1990 Canadian Jetta, then the DRL relay only affects the daytime headlights. That is all you lose by unplugging it. The parking lights are strictly a function of the headlight switch. It leaves circuit 58 connected to power all the time, it's just that in position 0 it's through the load reduction relay so the key is required. I'll try to look this up in my A2 Bentley later tonight.

[The Infidel]

http://forums.vwvortex.com/zerothread?id=2015008

hope that helps.

[The Infidel]

sorry looks like youve already been in that thread

[A2B4guy]

OK I've been reading the A2 Bentley.....

I'm sticking with my recommendation, but.... under the DRL (Canada) section, there's diagrams for:
1990 Jetta German production up to Jan 90
1990 Jetta German production from Jan 90
1991-1992 Jetta German production
1990-1992 Golf

The 90-92 Golf shares the same diagram as the early 90 Jetta. It is the only one with a DRL relay. The relay is located not behind the switch like the Passat, but on the very right of the first row of add-on relays above the fuse box (3rd row up), relay location 18. This is the same location referred to in the other thread. Functionally it is exactly what we have described, so I think this is your system. Pull that relay and your daytime headlights should go off. The rest requires a non-DRL headlight switch.

The other two circuits show some differences, one has a 3-position switch and the other has a 2-position switch, but they both control the daytime headlights from the TFL pin on the switch. On these cars, unplugging the switch would kill the headlights.

[VWJETS]

Quote, originally posted by A2B4guy »

On these cars, unplugging the switch would kill the headlights.

Not mine. When I unplug the switch, the headlights stay on, but all the auxiliary lights shut off.

I'm going to try pulling the relay and looking for a TFL pin on the switch.

Thanks for the help and info. I'll provide feeback once I try this.

[A2B4guy]

Quote, originally posted by VWJETS »

Not mine. When I unplug the switch, the headlights stay on, but all the auxiliary lights shut off.

That was referring to the other schematics of cars that DO NOT have a DRL relay, not your car.

[VWJETS]

I have to do some digging. My fusebox looks like the one in the Bentley Manual for the 1990-1992 Golf, except it doesn't seem to have the "add-on" relay section that would contain the relay for the DRL.

I have to see if it is behind the fusebox. The PO installed an alarm on the car and there are a few extra wires plugged into the fuse/relay system.

Once again, thanks for the help. I will provide an update when I give this another try.

Thank you.

[A2B4guy]

It is supposed to be the third one up on the right side, unless as you say they placed them differently on yours. Puzzling, but not unlike VW. I think it's not so much that VW did strange inconsistent things with wiring, but rather that VW uses many different vendors and suppliers for wiring harnesses and Bentley is not able to see and document every possible variation.

[VWJETS]

I pulled out the switch and found that there is a pin labeled TFL. The parking lights/markers shut off, but the headlights still came on.

It's going to be a guessing game, but I will find the relay. There is no relay box under the hood.

I will have to continue digging in the fusebox area for the relay.

[VWJETS]

TFL pin goes into a socket with no wire going to it. Therefore it is not the DRL wire.

http://forums.vwvortex.com/zerothread?id=277646

The above link points to a discussion that claims there is a relay for the DRL on the wiring harness about 5 inches down from the switch, within the foam tube.

I'll check for it after work. (I'm still waiting for my bentley manual to be shipped...so if anyone can confirm this for me, please do).

[A2B4guy]

Aha! Just what I spoke of at the top regarding the 1990 Passat. Maybe it is the same as the Passat after all. gonesouth says it is about 5" behind the headlight switch plug, inside the foam. The A2 Bentley knows nothing about this, though. I pretty much laid out what it says earlier. Dig that sucker out and unplug it.

[VWJETS]

SUCCESS!!

I found and removed the relay during my lunch break.

A2B4guy was right, just like the Passat. The relay was inside the dashboard about 5 inches down the wiring harness for the switch.

Now I have to find how to kill the parking lights properly. I have a 3 position switch.

Position 0 and Position 1 run the parking lights, and position 2 runs all the lights.

The TFL socket is has no connector, but there is a socket labeled "X".

I will study the threads and see what I can do.

A2B4guy, thank you VERY MUCH for your help and insight.

[A2B4guy]

There is no way you can achieve what you want with that switch. X means connection to the load reduction relay. The diagram for the switch has the parking light circuit hard-wired ON. You need a non-DRL switch from an earlier Mk 2, say 1988, or a US car. Check the Mk 2 classifieds for cars being parted out.

[VWJETS]

IIRC, the Load Reduction relay gives power to the parking lights when the key is turned to the "on" position, and turns them off when the key is in the "off" position.

If I pull out the Load Reduction relay, or cut the "X" wire, then the parking lights will not get power when the key is turned "on".

Will the parking lights get power if I operate the switch?

I don't have the diagram yet.

[A2B4guy]

In the OFF position, the parking lights are powered by the load reduction relay. In both ON positions they are powered from the battery.

If you disconnect the wire from the LR relay, your headlights won't work at all. Remember, your headlights go off when the starter is turning, so that's where they get their power from. There is no option, you must change switches!

[VWJETS]

Mission accomplished.

I picked up a used non-DRL 3 position switch. When I plugged it in, it functioned properly on the outside, but I had no interior lights.

I made some lead wires and studied the markings on the back of the original switch, and the replacement switch, and made the connections from the harness to the corresponding terminal on the "new" switch.

Everything works perfectly now.

Position 0 = no lights at all.
Position 1 = dash lights + parking lights
Position 2 = full lighting system.

I can return everything back to factory spec by re-installing my original switch and the DRL relay.

Special Thanks to A2B4guy for all the help!!

[MK2-16vT]

so i did everything posted on this thread and i have lost dash illumination now even with the headlight switch in the ON position. So how do i re-pin the connector to get my dash light back??