Headlight relay mod revisited.

[GOOSE]

Check to make sure the relays are wired correctly. It sounds like you are backfeeding the headlight switch somehow. Disconnect the relays and see if the issue disappears. If it does, I'd study the relays a bit more.

 

[X-NRCan_IDI]

I'll give that a try and see.. hopefully its something simple. Thanks!

 

[X-NRCan_IDI]

Messed around unplugging the relays and changing which set of wires they're connected to (I've got the pigtail plugs). I found that if I had either one unplugged, I had no running lights (in the headlight) and no buzz. Both plugged in, buzz with key on. Running lights are always on with key on. I'm thinking the running lights have to do with it. I don't know for sure where to go from here. I wouldn't care if I lose the running light feature.
I'm prettyyy confident the rest of my wiring harness is correctly wired and installed (aside from having the high beam wire mixed up with low beam wire thanks to incorrect information I found... I spent a good bit of time checking and re-checking again before I soldered my connections (except crimped ring terminals) Got all connections covered in shrink wrap too and tidied away in loom. Was a bit disappointed when I heard that buzz and also realized my really bright "low-beams" were in fact my high-beams. At first I thought, "Dayyyum! This mod works AWESOME!"

*Edit
Don't mean to hijack your thread Goose, but if it has to do with the running lights, perhaps it may be helpful for anybody doing this relay mod on a Canadian truck...

 

[GOOSE]

No biggie, the important thing is to get your truck straightened out. Its possible the headlight switch could have bit the dust but I'd say unlikely. Did you put a fuse in your new headlight harness? Does the ailment go away when the fuse is pulled?

By the way, my truck was assembled in Canada, go easy with the Canada thing......lol.

 

[anotheridi]

Not sure if this applies but some of those relays have a Diode on the coil instead of a resistor, if this is the case the positive wire needs to go to the cathode side (with the line on it), and negative on the anode side.

 

[X-NRCan_IDI]

I wired a single 25A inline fuse between the power source (solenoid on p-side fender) and the relays. Haven't tried it without the fuse in yet...

I wouldn't know where to look to find out if there is a diode or resistor in the relay... I bought two which have the 30, 85, 86, 87, 87a connections. I did not use the 87a wire; just taped the ends. The relays had a small diagram on the sides of them showing which was the power source for the switch, which is the ground, where power goes in (30) and where it comes out with switch energized (87) and de-energized (87a) to the best of my understanding.

Yea, you're right... I shouldn't be too ******* the Canadians... its kind of hypocritical lol

 

[anotheridi]

Most relays the polarity doesn't matter but I think the ground for the coil on those harnesses is a white wire which may throw people off, normally this isn't a big deal but if your relay has the picture of the coil and there is a diode pictured between the coils and it's wired backwards then it could cause your issue. The diode picture looks like an triangle with a straight line at the point.

Again I'm not sure this will apply to you, I'm just trying to give you something to look at.

 

[riotwarrior]

Hey, this could BE the Canadian thing and just cause yer truck is ASSEMBLED in Canada but built for US means it may NOT apply...

We Canuckleheads here in Canada got Daytime Running Lights before US folks did. It's a small module about 4"x4"x1" usually located on LH side of truck in front of rad support behind grill, ..somewhere I can't recall where exactly it's a finned box looks like a small car audio amp

Here I just snapped these images for ya'll

Here is Brick nose, behind grill Low and off to LH side

You must be registered for see images attach

Here is OBS and it's again LOW Behind grill and appears to be behind signal lamp...

You must be registered for see images attach

That DRLM feeds a lower voltage to HIGH beams when key is on RUN position. This has been an issue with relay mods on more than one Canadian truck. It could be that it is too low a voltage to correctly trigger relay IIRC and subsequently screws with whole light system.

If you remove the DRLM from the equation by disconnecting it, your HB/LB lights will function as plain HB/LB but your dash HB light most likely will not go out.

Hope that this helps out my fellow Canuckleheads

JM2CW today

BTW I've been trying to figure out how to make the DRLM feed to a secondary bulb so not to burn out nice bulbs when I do relay mod removing it from the system so to seak.....

Not sure the above can be done.

E D I T

To add above pictures and locations of DRLM for Brick nose and OBS trucks

 

[GOOSE]

Thanks Al, learn something every day!

 

[rlb245]

You can get the weather proof box along with everything you need from MCM electronics dot com

 

[dunk]

That explains why most of the older vehicles in Canada had headlights on during the day. Thought that was odd, and of course annoying. When everyone drive around with headlights on all the time it's the ones without headlights that stand out. Never seen that on any of my Canadian built trucks, but mine were all 86 or older so I'm guessing it was late 80s they did that.

 

[opusd2]

I essentially did this mod off of the driver's side, bought a couple of connectors from the local parts store that connect to the headlights, and with a meter figured out which was which from the headlight switch.

From that I have my two relays feeding the low and the high beams using heavy wire to each terminal on the bulbs, including the grounds which were grounded directly to the closest battery. Gave me a very good increase in output. Next step is upgrading the headlights from the standard Philips to a Hella setup with a little more OOOOMPH behind them and nice replaceable bulbs and not having to replace the glass. I know I am heating the snot out of things because on high I run both high and low. But I figure when the headlights go, and I use up the replacements I have sitting around, I can upgrade to a better headlight setup.

Add this to my Hella 500s and I can light up the darkness quite well. I initially did this to my 89 GMC when I first bought it, so this is one of the first things I thought of adding to the mod list.

 

[X-NRCan_IDI]

Thanks Al! Make sure you post your set up if you get around to wiring that DRLM differently! Looks like I'll just have a blue light on my dash for a while.

 

[Agnem]

Going back to the earlier question, relays do not require a diode on the coil. But a computer, or other electronics do. If your going to drive a relay with a silicone device, use one with a diode. If you are running it with a toggle switch, or other mechanical interrupter, then there is no worry. The reason for this, is that when current is broken to a relay coil, it generates back EMF as the magnetic field collapses. This induces a voltage spike in the supply line that can blow out the driver transistor. The diode will effectively short circuit the back EMF and prevent it from damaging the semiconductor trying to control the circuit.

 

[typ4]

As a side note, I recommend using a breaker in the relay batt feed as it will reset, if a fuse blows you will be lights out and that would be very bad. Relays just need to be mounted plug down to keep water out and they last well.