Neerrrr, wiring!

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 12:03 am

I have two good headlights which I tested off the battery. The problem is the switch won't turn on the high or low beams! All the other lights on the car work fine, with the exception of the dome light, but I think/hope that's a separate issue where I just need to clean out the door switches, since I've verified the dome light's getting power from the head lite switch via a test light.

The headlight switch shows power at terminal 5 when clicked out once, and terminal 3 when out all the way. However, even though it's out all the way I get no power from the high or low beam connector in the engine bay. Where are the connectors and Y/W positive wires that go to the lights shown in the Bentley? Aside from a dead dimmer switch (actually three dead switches), which all dim the dash lights, and the wiring itself, those are the only things I can thing of checking.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 4:48 pm

Alrightly then, when the headlight switch is off, only 6&7 are powered. With the parking lights on, 4,5,6&7 get juice, and with the high and low beams on, 2,3,4,5,6&7 get juice. 1 however, never gets any juice, and is connected to the interior light. Which is getting power, but not getting grounded when the doors open.

82vdub · Post by **82vdub** » Sun Jul 22, 2007 5:09 pm

I will say that chasing wiring problems can be very frustrating and time consuming, as you probably are quite aware by now.

One question, why would terminal 6 have power if the headlight switch is in the off position? From the picture and my belief on how the diagram works (it's a european wiring style diagram), terminal 6 is the output from the headlight switch turning on the taillights.

If terminals 6 and 7 have power as you say when the switch is off and have power when in any of the on positions, then the taillights will always be on. Have you verified that this is true?

I will also add that if systems aren't properly grounded, you're running a floating ground situation that is extremely difficult to troubleshoot. Have you verified your ground connections at the taillights and headlights? Also, if you have had a lamp fail, they sometimes can fail in a shorted condition, leading to all other sorts of troubleshooting issues. I've always pulled each lamp out of the circuit when troubleshooting taillights or headlights etc. The lamp is nothing but a resistor to ground and trying a test light with the lamp still in the circuit adds another area of potential confusion.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 5:23 pm

Alright, the driver's side door switch is busted, so that's one, albeit secondary problem, down. Does anyone know what numbers I can jumper in the harness to see if I really do have three busted switches?

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 5:38 pm

82vdub wrote:I will say that chasing wiring problems can be very frustrating and time consuming, as you probably are quite aware by now.

One question, why would terminal 6 have power if the headlight switch is in the off position? From the picture and my belief on how the diagram works (it's a european wiring style diagram), terminal 6 is the output from the headlight switch turning on the taillights.

If terminals 6 and 7 have power as you say when the switch is off and have power when in any of the on positions, then the taillights will always be on. Have you verified that this is true?

Good catch! It's 4&7 off (key in ignition), 2,4,5,6&7, one click out, and 2,3,4,5,6&7 two clicks out. Which makes sense. And 1 works as a ground for the dome light when I turn the dimmer switch and it clicks.

So, if these are getting power as it seems they should when I turn the lights on, two clicks out, but I'm not getting power in terminal 3&4 (Y & W wires) on the outgoing connector, it must be a problem with the dimmer switch, or the wiring between the two, right?

82vdub · Post by **82vdub** » Sun Jul 22, 2007 5:51 pm

Well, you say you're getting power output at terminal 3 on the headlight switch when it's pulled all the way out. If that's the case, have you verified that you have the same power at terminal 56 on the dimmer switch? If you don't, the wire is broken somewhere in the middle. If you do, I believe 56 energizes the coil to the dimmer relay. I think 30 is the main power source that either feeds 56a or b when the circuit is energized.

Verify that you have power at 56 next. If you do, verify that you have power at 30, if you do, then verify that you have power coming out of the dimmer switch, either 56a or b.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 6:01 pm

You wouldn't happen to know where 30/56a/b and the R/GY wire are? All I see on the switch/dimmer are the 7 wires from the connector, and 31 which I'm guessing is ground. I don't see where the two wires are that connect to 56a&b. I mean, I see then in the BL 10pin connector the Bentley refers to, but they aren't connected to the headlight/dimmer switch.

82vdub · Post by **82vdub** » Sun Jul 22, 2007 6:11 pm

The short answer to your question is no, I don't know where those specific wires are. The 30, 56a, 56b should be terminal numbers on the dimmer switch. I don't know what year car you have and am (thankfully) not very familiar with tracing wires on a VW, but old GM's with the column mounted headlight selector switch (that's labeled dimmer switch in the wiring diagram) had the headlight dimmer switch actuated by a rod coming down the steering column. Since I believe all VW's of recent era (80 and newer) have the column mounted headlight switch, chances are the dimmer switch relay is located on the column somwhere. I've had luck chasing wires by looking for a bundle of wires that have the same color codes as the one's I've been tracking down. In this case, it's R/GY, W/BK, Y, and W. You'll be at least looking for those 4 wire color codes.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 6:45 pm

Oh hell, you're right on! When I was putting in the manual transmission pedal cluster (auto/gas to manual/diesel swap) I must have bumper the dimmer switch connector on the steering column. One last question, for mk1 golfs/bunnies, you wouldn't happen to know how to turn on the brights?

82vdub · Post by **82vdub** » Sun Jul 22, 2007 6:49 pm

So did you get the problem fixed? On my A1 Rabbit, the headlight dimmer switch is done by actuating the left actuator coming off the steering column behind the steering wheel. That's a consistant position with most cars on the road today.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 7:01 pm

Yup, just wiggled it in and they turned on, thanks a lot! The only problem is when I move/click the turn signal stalk toward me, the lights turn off. Not sure if I have just highs or just lows, but at least I have lights! I'm gonna take out the glove box&knee bar so I can drop the steering column and make sure all those connectors are snug.

82vdub · Post by **82vdub** » Sun Jul 22, 2007 7:02 pm

It probably just needs to be adjusted properly to work. I've had that on old GM cars before. At least most of this issue is solved for you

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 7:53 pm

I'm thinking that's it, since on the low beam setting, I have no lights, but the test light says that both the high and low beam connector attached to the light are getting power, however when I'm on the high beam settings, only the high beams get power. It's like the actuator is stuck halfway and is giving both bulbs current, but not enough for either of them to light up.

82vdub · Post by **82vdub** » Sun Jul 22, 2007 8:02 pm

Could be a stuck/faulty relay, but I'm going to default to the idea that the position of the switch needs to be adjusted. If I pull the headlight dimmer switch and hold it, both the high and low beans will operate on my A1 Rabbit. Undo the bolt or screw that holds the relay to the shaft and play with it and see what happens. It sounds like it's never really getting to the low beam switch position.

lyeinyoureye · Post by **lyeinyoureye** » Sun Jul 22, 2007 8:22 pm

Figures VW would design it so that I have to take off the whole steering wheel just to get at it.

Ah well, I'll check it when I nab that 24mm socket I've been eying, I need to center the steering wheel anyway. Thanks again!