E-Code Relay Placement: Stupid Questions Edition

If you don't want to split the wires going to the headlights you can get relays with dual outputs. The 'K' relay found in 200 models (Bosch part #0 332 015 006) is one such relay but it only handles 15 amps/circuit.



This Hella relay is rated for 20 amps/circuit although it may be difficult to find.

Yup you are correct. That relay you have switches between 87 and 87a. So just use 87 and split the wires or get the dual output relay. The Hella one above is really good to use since it's 40 amps rated.

This is the one I have used in the past. http://www.rallylights.com/hella-hl87118-mini-relay-12v-40a-spst-dual-87-pin-bracket.html

I have piggyback spade terminals here at work, so I can probably terminate to one of those and use female spades to run the 2 wires in a way that looks a little neater.

Make sure those piggy back adapters are rated for current like a headlight. Probably are fine but just a thought. There is already a hole in the sheet metal that works for the relay bracket at that spot in the picture. Bright lights big city.

I'm sure they're good, they're from work. They were purchased to handle pretty high currents from chillers and pumps on targeted temperature management therapy units. Good digikey stuff, not autozone junk.

I think I'm pretty good to get started tonight save for one thing...Where are you guys pulling the trigger wire from for pin 85? Looks like the H4's are 2 powers and a ground, so surely the trigger wires are upstream somewhere?

The 85 trigger wire on each relay is connected to an existing headlight wire. One for low beam and one for high beam. The ground wire for the same headlight connector is used for the ground 86 on each relay.

In the aftermarket harness this is where they use the male headlight connector to plug into an existing headlight connector to trigger the relays.

OHHHH right, I forgot all about that male connector thing. Ok, so I probably just have to add a length of wire from the existing wire on the far side, and use the existing ones without lengthening on the driver's side.

Unless you totally want to balance out the bulb out circuit No need to run wires from the old ones on the passenger side. You only need to trigger the relay from the left side for both headlights on your new harness. I only connected the harness to the one side and it doesn't have a bulb out light on. Probably not enough current in that part of the circuit for it to function anymore.

After an insane amount of thrashing with the old headlights, they're installed. Harness is hooked up.

Doesn't fkin work.

I didn't have much time to troubleshoot since I was long past out of daylight, but I have power through the fuse box but not at the H4 connectors. So My guess is the relays aren't doing the clicky clicky, or they aren't getting the trigger signal. I didn't have time to double-check my wiring, so hopefully the rain will hold off and I'll have time today. I also admittedly am using the bulbs that came with them, and I have no clue what kind of condition they're in. Just trying to get them running at this point.

But also, one of my corner lights/turns doesn't work. I have yet to change the bulbs (visual check was ok, but that's unreliable) but here's the thing...The passenger side corner light has 3 wires in the 3-wire connector, and the driver's side has 2 wires in the 3 wire connector. Receiving end has 2 wires each. Both have an additional ground.

The side with 2 wires does not work. No marker lamp, no turn signal. Anyone have any idea on the different wiring? The boot covers were different, too. One genuine and one aftermarket, perhaps? They look so similar in quality that I hadn't really considered that they might be different until I was installing them and noticed the wiring.

The side lights can have the extra wire for a daytime running light. Not always but it can be there. So maybe you have one with a drl and other doesn't.

If you have no power on the lights. I agree start with the trigger signal pin 85 on the relays. If that is working then you want to make sure the ground on pin 86 is working otherwise the relay won't turn on at all. For ground checking with a test light connect the clip to power and check that pin 86 turns on the test light.

Ok, so here's what I've got so far...

Power at the fuse junction, both iin and out is good.
Power measured at the trigger junction amd relay ground is good.
Power at the H4 connector is .5 V

Relay no go clicky, I think. But why? I've swapped out for ice cube relays and had the same exact result. Swapped out the fuse panel for a fusible link. Nada. Bupkiss. Checked thr ground, got nothing.

Also powered the 87a to make sure something isn't backwards. Nada to the H4.

NEVERMIND, I DUMB. Wow.

Use a test light to make sure the connections conduct. I just had a bad ground on my brothers 91 BMW install with this same stuff. It was the ground for the headlights themselves on the right side in his case.

So you are providing power on 86 and it is grounded on 85 then the relay should be on. You should measure constant hot power on 30. 87 should be on only when you apply power to 86. If that is working move to checking the continuity to the headlight connector if you aren't lighting the test light on the headlight connector.

I missed a ground.

But now I have a different problem. Low and high beams are all good.

But NO turn signals. Standard fast-flash from the dash, nothing up front. No corner lights, either. And the left tail light is now out, as though the fuse for the turn signals and left tail is blown. But I tried spinning the fuse, tried changing it, not blown, but not working. Something on that circuit isn't right.

I ran out of daylight AGAIN, so I think I'm gonna go to work late rather than drive 60 miles like an as$hole with no turn signals. Maybe I missed another ground in the dark. I did have to take it all apart to finish the final routing and looming.

When I installed the DJ ecodes they had wires wrong on the park/turn signal connectors. I had to switch things around. Good find on the ground. Looking at it with a new day will help you figure it out.

ALLLLLRIGHT.

So after a combination of things being broken, backwards, and just WRONG on my behalf...

Turn signals work. Headlights work.

But only passenger side parking light works.
No hazards (maybe been like this forever, I'm not sure at all.)
Driver's side tail light is still out. No dice on bulb change. 0V getting to it.

What could I have bumped in the process that would have kicked my tail light power? Fuse is still good, too.

Check the bulb out relay for a no pass through problem. The tailight circuits pass through the relay. You should see 12v in and 12v out from the relay.

Double check fuses. Because if they are the pot metal they will look good and be open. For the no parking light it could be the same thing with the bulb out relay if there is 0v at the socket. Should see 12v in and 12v out of that circuit on the relay as well.

Well allllrighty.

I had a bunch of red herrings with the fuses. Despite the fact that I recently removed, cleaned, adjusted, greased, and replaced every single damn fuse and position, a bunch of them wanted to be spun.

So now all the lights work! Success!

However, I need to get these bad boys not pointed at the sky. Any memory on whether the upper or lower adjusts vertical position? And what happens if I'm turning it and nothing happens?

Those damn fuses! At least those are easy to deal with. Did you get the lights to adjust?