Weird headlight problem

[hunter1]

So I just installed headlights and relay harness this morning and everything worked great. Low beams, high beams and switch all worked as it should. This afternoon I had started the engine after making some adjustments with the fuel injection handheld and was letting it warm up to operating temp. I turned the headlights on and was looking at their brightness with the engine running when they switched to hi beams on their own. I went and depressed the hi beam floor switch but they would not go back to low beam. I also turned them off and when I pulled the switch back out the headlights came on in the parking light position and still on high beam only. Does this sound like a light switch problem? I had read that with the higher wattage halogen lights that they would cause switch issues if you ran them without the relays, but as I said I do have the relay harness. I checked all the grounds and everything looks good, just seams like the switch is stuck internally or something? Anybody had issues like this before?

 

[DirtDonk]

A little different than the normal problems. It’s possible to be a switch I suppose, but it sounds like one of the relays is defective. You might swap the relays and see if anything changes.
At least as a first test.

 

[DirtDonk]

It would also be a good idea to test the floor switch. The simplest, without an ohm meter to test, would be to unplug it and jumper each section, high and low, to see if anything changes.

 

[hunter1]

Went back and unplugged the dimmer switch and headlights were still on and on bright. So ruling that out went to see which post the power was on the original harness coming in. As I touched the pin on my test light to one of the 3 post on the back of the connector, the lights dimmed. Took it off and bright. Ran a test lead to that post and grounded it, plugged the dimmer switch back up and everything is working like it should. Double checked the grounds again and all good. So I believe it is a relay as Dirtdonk mentioned since everything was working normal initially. This is about a 4 yr old kit but new. Kinda disappointed that a relay didn't last that long.

 

[gnpenning]

This is going to be a good example of why everyone should have a cheap dvom and know how to use the basic functions. You only need a $20 one and don't have to be a electronics guru.

In the meantime you want to isolate potential areas for trouble. Switch, high/low switch, wiring, lights, relays.

By far the quickest and easiest test will be to unplug your relay harness and go back to the original setup. You are only doing it for a quick test to see if anything changes. If it starts working as it should double check by plugging the relay harness back in. If it goes back to causing issues you found your problem. If nothing changes then you will want to isolate the high/low beam switch which is easily bypassed with jumper wires.

The process of elimination is your friend. Please don't start replacing any parts until it's been tested and proven bad. You may very well introduce a new problem or mask an existing one. New doesn't mean good and don't throw anything away.

Bypass the relay harness and report back. You got this.

Edit: you answered while I was slow typing.

 

[DirtDonk]

Went back and unplugged the dimmer switch and headlights were still on and on bright.

So as you found, that means it’s in the relay harness. Whether a relay or a shorted wire.

So ruling that out went to see which post the power was on the original harness coming in. As I touched the pin on my test light to one of the 3 post on the back of the connector, the lights dimmed. Took it off and bright. Ran a test lead to that post and grounded it, plugged the dimmer switch back up and everything is working like it should.

Don’t leave it grounded when you fix the issue. That becomes a dead short from the main power wire.
Luckily, the headlight switch has a built-in circuit breaker. But you don’t wanna keep testing it the wrong way!

Double checked the grounds again and all good. So I believe it is a relay as Dirtdonk mentioned since everything was working normal initially. This is about a 4 yr old kit but new. Kinda disappointed that a relay didn't last that long.

An unfortunately all too common problem with cheap imported relays.
And believe me, when you can get one of these harnesses premade as nice as they are for $30-$40, they are in fact “cheap” relays being used!
Even ours.
That said, we have a very high success rate with our harness, in spite of the noted failures. It’s probably a higher failure rate than we would like, but a lot lower than it could be. At last check, probably less than 5%. But it’s those 5% that are the most annoying!
Failures occasionally have immediately, but usually within a week. With yours last lasting so long, I’m guessing they just didn’t like sitting, unused, and maybe moisture in the air, took its toll inside.
Even expensive relays have this issue.

Luckily, the relays are available in higher quality from the local parts store. Someone here has the generic part number. I’m sure. I can’t remember it and I can’t remember where I wrote it down!

Good luck getting it sorted. I would still swap the relays before buying new ones. Make sure it’s a relay issue and not a Wiring Issue. Corrosion starts anywhere
And don’t forget to remove that ground jumper.