80/100w high beams not working

[Dayzedandkonfuzed]

Installed these same lights on my Malibu with no issues. Not sure why I cant get them to work on my Jetta. Low beams are fine, high beams dont work. Only getting 70mA from my factory high beam wire to the relay socket. Tested the passenger side and it had 12v, until I hooked that wire up as signal instead of the driver side, now I'm only getting 70mA again. I'm assuming this car has a daytime running light module even though the DRLs dont work, could that be giving me grief?

 

[sandmansans]

more than likely due to the wiring not sufficient for the load. You should be drawing a little more than 8amps
The proper way to do it is via upgraded wiring/ceramic sockets and dedicated relay to each bulb.

Id go 12 ga copper wire. A little overkill, but remember voltage drop per distance

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[Dayzedandkonfuzed]

more than likely due to the wiring not sufficient for the load. You should be drawing a little more than 8amps
The proper way to do it is via upgraded wiring/ceramic sockets and dedicated relay to each bulb.

Id go 12 ga copper wire. A little overkill, but remember voltage drop per distance

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Sorry should have mentioned that's all done with new sockets, 2 relays and 14ga wire.

 

[sandmansans]

Oh good haha you had me worried for a minute.

Did you check your grounds?
Its been a while since I've owned a mk3, but I don't remember it having DRL.

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[sandmansans]

Also you didn't mention if you were getting 12v on the side that you're having issues? 70 ma isn't much.

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[Fixmy59bug]

Its been a while since I've owned a mk3, but I don't remember it having DRL.

According to google, Canada has required DRL's since 1989 or 1990 (conflicting dates)

 

[PB_NB]

I bypassed my DRL's a long time ago by modding the relay triggered by releasing the e-brake. I use my city lights as my DRL's have to turn them on manually.

Modding the relay was easy as I recall, Just opened it up and put some electrical tape between the contacts.

Maybe this will help to rule out the DRL circuit.

This is an "Off Road Modification" as it does disable a safety feature. Use at your own risk.

 

[Dayzedandkonfuzed]

Also you didn't mention if you were getting 12v on the side that you're having issues? 70 ma isn't much.

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Sorry.... tired last night, I meant 70mV. So no, not getting anywhere near 12V.

I'll try disabling the DRLs and see what happens, cant hurt anything as they don't work anyway.

 

[nokivasara]

Re-check the wiring to the relays. 70mV sounds more like measuring a voltage drop on a circuit...
Or bad grounds like someone already mentioned.

 

[Dayzedandkonfuzed]

Re-check the wiring to the relays. 70mV sounds more like measuring a voltage drop on a circuit...
Or bad grounds like someone already mentioned.

Gone over wiring 3 times, and have everything grounded direct to battery. Only other thing that comes to mind that I haven't checked is the relay sockets I'm using I salvaged from my Cutlass, and I'm starting to recall having issues with the power locks in that car, so maybe I have a bad terminal in that socket...

I checked the voltage to the low beam socket using the ground in the high beam socket and everything looks good. I have both beams sharing a ground and both 85 terminals sharing a ground, so I'm sure I don't have a ground issue, unless not having power grounding through the factory socket ground is a problem. These cars don't ground through the ECM do they?

I have a good understanding of electrical and have done lots of this kind of work, however I am new to these cars so I could be missing something on the German Engineering side lol

 

[nokivasara]

So just to be clear (I tend to misread stuff ) you have 12V on the high beam lead in the car?
But when that lead is connected to the relay nothing happens?

I wonder if the relay is faulty and the 70mV (on 87?) you see is "leakage" from #30 on the relay?

 

[Dayzedandkonfuzed]

Well it's strange... I had 70mV at terminal 86 on my relay socket, cut it off and tested the factory wire. Still only 70mV. So I tested the factory headlamp socket on the passenger side (have everything connected to driver side harness,) and had 12V at the high beam. So I cut that, connected it to the relay socket where the drivers side had been connected, and had 70mV at 86 again.

Also I'm testing without relays plugged in.

 

[nokivasara]

Ok, I really don't understand what's going on here.
But one way to get it working is to use the 12V high beam on the pass side to trigger the new high beam relay (with two 87s) to power the bulbs.
Get rid of the sockets and use spade connectors or solder the wires to the relays.

Do both high beams work if you use the original wiring/sockets and 55w bulbs?

 

[sandmansans]

Id ground each side and see what happens.

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[Dayzedandkonfuzed]

But one way to get it working is to use the 12V high beam on the pass side to trigger the new high beam relay (with two 87s) to power the bulbs.


Do both high beams work if you use the original wiring/sockets and 55w bulbs?

lol, that is what I explained in the last post, which still didn't work.

And yes, both high and low worked fine with stock wiring and bulbs

 

[Dayzedandkonfuzed]

I need to fool the ecm because the lights ground through it. When I check term 86 for power, grounding my voltmeter direct to the battery, I get 70mV, but if I ground my voltmeter in the factory socket ground, I get 12V. That tells me this is dependant on the ecm seeing ground. I'm going to ground my 85 terminals to the factory sockets tonight, I think that will fix this.

 

[SilverSquirrel]

Good fun..
Reminds me of my 82 Scirocco that I owned in the early 90s.
I put 100w H1 bulbs in all 4 lamps. 10 gauge wires, right to the bulb terminals, 4 relays, 4 in line fuses, and 4 10g grounds right to the battery.
Had the yellow hella fogs on relays too...
High beams with all 4 flame throwers was WAY brighter than todays HID headlights... lol.

 

[sandmansans]

Good fun..

Reminds me of my 82 Scirocco that I owned in the early 90s.

I put 100w H1 bulbs in all 4 lamps. 10 gauge wires, right to the bulb terminals, 4 relays, 4 in line fuses, and 4 10g grounds right to the battery.

Had the yellow hella fogs on relays too...

High beams with all 4 flame throwers was WAY brighter than todays HID headlights... lol.

Ha yeah good times. I've got 100/130 h4 bulbs.....they're BRIGHT!!!

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[nokivasara]

lol, that is what I explained in the last post, which still didn't work.
And yes, both high and low worked fine with stock wiring and bulbs

Ok, I didn't realize you put the pass side 12V lead directly to 86 on the relay. No sockets or other wires in between. Use the same ground point that you used when you measured the voltage to be 12V.
If it still doesn't work I'd say that the car is cursed because that would be impossible...

 

[Dayzedandkonfuzed]

Ok, still pulling my hair out.

Have both 85 terminals grounded to both factory headlight grounds. Have 86 terminals hooked up to low/high beam wires (seperately, of course) on BOTH sides of car. Bascially I have now wired the relays in place of the headlight sockets so the ecm sees power going out and back. Power to 30's is coming direct from battery, fused, separate for each relay. Headlight bulbs are grounded direct to battery.

High beams now work, except once they're on they won't turn off with the dimmer switch. I have to turn the headlight switch off and back on to return to low beam. When on low beam, my high beam indicator is dimly lit. Also, I'm only getting around 8V to the low beam relay (both 30 and 86 terminals) when probing the 85 terminal for ground, which in turn is only sending 8V to my bulbs. If I ground the voltmeter to battery, I see 12V at that relay. Obviously my issue is on the ground side. If I pull the low beam relay, high beams turn on and off as normal. Seems like a backfeeding issue, but I can't see where anything I've done could be backfeeding.

With only 8V to the relay, my low beams are basically non-existent. I think I could fix this by grounding the bulbs to the factory harness, but I'm worried about melting the factory wire, or worse, damaging the ecm.

I wish I had tested for voltage before I did any of this... My headlights were pretty bad before, so there could be a completely different underlying issue here. I pulled the headlight switch last night to disconnect the DRL's, and found it was already replaced with an auto wrecker switch. Also, the terminal for the DRL's on the switch was folded right over, so they haven't been connected this whole time. I bent it back straight but that did not change anything.

 

[PB_NB]

Try the DRL relay. See if you can locate it and turn it off (disable the points from touching) but leave it connected because it activates the e-brake indicator on the cluster (I just put some electrical tape between the points many years ago). It might be causing the issue with the lower voltage.

Do the DRL's come on when you release the handbrake? When you are taking all your readings. is the handbrake released or up? That was my trigger for the DRL's to come on. I didn't bend any of the tabs on the switch or disconnect anything there. I did put a euro switch in so I could run my fogs without the headlights. I was running HID's in the low beam spot and didn't want the lower voltage from the DRL's to mess up the ballasts. That's my reason for the DRL disable in the first place.

 

[Dayzedandkonfuzed]

Handbrake is down, and DRL's don't come on ever. At the moment my park brake doesn't work, so is there any harm in simply pulling this relay out for now?

 

[PB_NB]

I am not sure if pulling the relay would help but it is worth a try. Since that circuit is designed to supply lower voltage to your lights. Sounds like a good place to test.

 

[Dayzedandkonfuzed]

that circuit is designed to supply lower voltage to your lights.

Exactly why I'm leaning toward DRL's causing my trouble here. I get the feeling it may be regulating the voltage on the ground side. That is relay 173, right?

Also, VW wiring diagrams suck.

 

[nokivasara]

Ok, still pulling my hair out.

Have both 85 terminals grounded to both factory headlight grounds. Have 86 terminals hooked up to low/high beam wires (seperately, of course) on BOTH sides of car. Bascially I have now wired the relays in place of the headlight sockets so the ecm sees power going out and back. Power to 30's is coming direct from battery, fused, separate for each relay. Headlight bulbs are grounded direct to battery.

High beams now work, except once they're on they won't turn off with the dimmer switch. I have to turn the headlight switch off and back on to return to low beam. When on low beam, my high beam indicator is dimly lit. Also, I'm only getting around 8V to the low beam relay (both 30 and 86 terminals) when probing the 85 terminal for ground, which in turn is only sending 8V to my bulbs. If I ground the voltmeter to battery, I see 12V at that relay. Obviously my issue is on the ground side. If I pull the low beam relay, high beams turn on and off as normal. Seems like a backfeeding issue, but I can't see where anything I've done could be backfeeding.

With only 8V to the relay, my low beams are basically non-existent. I think I could fix this by grounding the bulbs to the factory harness, but I'm worried about melting the factory wire, or worse, damaging the ecm.

I wish I had tested for voltage before I did any of this... My headlights were pretty bad before, so there could be a completely different underlying issue here. I pulled the headlight switch last night to disconnect the DRL's, and found it was already replaced with an auto wrecker switch. Also, the terminal for the DRL's on the switch was folded right over, so they haven't been connected this whole time. I bent it back straight but that did not change anything.

Oh, this is getting interesting! We don't have the same setup with handbrake and DRL's over here so I can't help with that.
8V is such a strange number to get too, surely the factory DRL voltage is lower than battery voltage to save the bulbs but not likely by that much, more like 11-12V or something?

I agree about the backfeeding, doesn't sound like something you could have caused.

 

[Dayzedandkonfuzed]

8V is such a strange number to get too, surely the factory DRL voltage is lower than battery voltage to save the bulbs but not likely by that much, more like 11-12V or something?

Looking at how bright they are, I think 8V might be right. They look about as bright as DRL's should be, but I could be wrong

 

[nokivasara]

Ok maybe that is normal for DRL's. They must be very dim, almost glowing?
How does that work, are you supposed to get 12V to the low/dipped beam when the light switch is i the low beam position?


I hope you get it sorted, sounds like the best option is to find the right way to disable the DRL's alltogether. I doubt there is any harm to that, we are mandated to use the low beams at all times. The lower voltage is probably just to increase the lifetime of the bulbs.

 

[Dayzedandkonfuzed]

Ok maybe that is normal for DRL's. They must be very dim, almost glowing?
How does that work, are you supposed to get 12V to the low/dipped beam when the light switch is i the low beam position?

Yes headlight switch 'should' supply full voltage. And at 8V, they are almost orange and barely noticeable driving home at night lol. Good thing I live 50 miles from work

 

[Dayzedandkonfuzed]

Pulled the DRL relay, still nothing. However I did find some broken solder inside that relay, guess I know why the DRLs don't work.

 

[Dayzedandkonfuzed]

Never trust google image results. This has the high beam and ground backwards. So do many other pictures from google images. Man I feel dumb lol. As soon as I found a good wiring diagram for these I saw the problem right away. Haven't swapped the wires yet but I will tonight and hopefully have proper headlights again!