H4 Headlight Conversion Kit (TBR) Problem

[jrclift]

I could use some help on my H4 headlight conversion kit I bought from Tom’s Bronco Parts. I installed the upgraded wiring harness, which connects to the old harness and installed the head lights about 3-months ago.

The system worked great until about month ago and the lights would only work on high beams. All the other lights on the rig worked perfectly. I turned the switch on and off several times and the low beams would finally come on. This happened a few times, but not every time.

A couple of days ago it happened again, except turning the light switch on and off did not work. The low beams would not come on. Turning the high beam switch on and off did not work either and the lights work on high beam just fine.

I called and spoke to a TBR tech. He suggested maybe replacing the the high beam switch. I checked the 2 inline fuses, but they look good, but I will change them out anyway. He suggested testing the system with a meter from the headlights back. I’m not sure what I would be looking for. Obviously, there is power going to the headlights, since the high beams and all other lights work. Also, I replaced the light switch about 6-months ago and it has always worked.

Anyone else having problems with this system, or have any suggestions? The TBR people have always been easy to work with, but I don’t think the tech had any idea what was going on and was stabbing in the dark.

Thanx!

 

[75MIKE]

Swap the 2 relays and see if that makes a difference. I had a relay hang up that did the same thing.

 

[TexasDude]

I had a very similar problem with my h4 conversion kit as well. I posted on this forum and tried everything. Funny, the last guy told me to slap the crap out of the relays and see if it worked. Surprisingly, it worked. The relays get stuck. Also, I regrounded everything which I believe was also part of the problem. I ordered new relays from Ebay, and everything is working perfectly. I went to Napa first to buy the relays, but they were 6x more expensive there. I bought 2 relays for 8 bucks. I believe Napa wanted 30 dollars a relay.

First, try regrounded everything. If that doesn't work, try slapping the crap out of the relays. If it works, buy new relays.

 

[gnpenning]

I can't over emphasize enough the need for a DVOM and even a test light for EB ownership. You don't need a expensive one. A $20/$30 will work fine for most everything you will need to do. They are very easy to use, and many here can get you up and running quickly.

As mentioned try swapping the relays. If that doesn't fix it, then you need to test the high/low switch. For the high beams to work you need power going to this switch. Which you said you have. You should have 3 prongs on the switch. One will be power in from the headlight switch. One out for low beams the high beam will generally have 2 wires out. One for the high beam indicator on the dash, the other to the high beam lights. Clicking the switch the power out should switch from the high beam terminal to the low beam.terminal. If it only comes out one side and shuts off on the other, you have a bad switch. Let us know what you find and we can help you from there.

 

[jrclift]

Thanx guys. I have the weekend to work on it. I’ll let you know how it goes.

 

[jrclift]

Couldn’t wait. Turned on headlights and gave the relays a whack or two. Low beams came on. Unfortunately, when I turned the headlight switch off and then on again, the low beams would not come back on. Gave the relays another whack, or two and they came on. Repeated several times with the same results. I’m no diagnostician, but I think at least one of the relays is bad...thanx for the help. Off to find new relays and a DVOM, just to have on hand!

 

[jrclift]

Also, I have a ‘75 Ranger; 302; 3 speed automatic-C4; 2.5 inch lift; 32” BFG’s; long tube headers and an attitude

 

[bronconut73]

Put that data in your signature line like mine.

It will help people help you if they can always see what you have at a glance.

 

[gr8scott]

Put that data in your signature line like mine.

It will help people help you if they can always see what you have at a glance.

To do so, select Quick Links up top and chose Edit Signature.

 

[jrclift]

Got it. Thanx!

 

[broncobuddha]

Hate to revive an old thread but I now have this exact problem. I even have the led bulb upgrade from the H4s from Toms. Been running them for months with no issue. I had also done all leds on the outside and just finished up getting the rear led boards turn signals working.

Drove last night no issue. Drove home from dinner tonight and half way home boom not lights went out. Nothing looks amiss visually.

Hi beams got me home.

I bought the upgraded harness that plugs into the factory harness on the one side.

Anyone have a pic of the relays to smack? Shouldn't these be under some type of warranty?


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[Jdgephar]

The relays should be near the battery on the passenger side. They are cheap and easy to replace. I wouldnt bother with the warranty hassle.

Your looking for two small black boxes, similar to this:

https://www.amazon.com/Ehdis-Relay-...cphy=9017365&hvtargid=pla-684589914152&psc=1#

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[broncobuddha]

Yep, that's what I was envisioning. As a quick test this morning (no real time to spend) I turned on the low beams (no light) and just lindo smacked the relay with my hand. I saw the low beams flash for a second which makes me think that's the issue. Not sure how hard or with what tool people are smacking these with but I don't guess I'll hurt them if they're not working.

Just weird that a not 3 month old product is crapping the bed.

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[gr8scott]

is this the harness you got from Tom's? If so, not sure where you're going to source those type relays from...

Edit: I guess they're available.
https://www.amazon.com/MICTUNING-li...4+pin+automotive+relay&qid=1600404689&sr=8-17

 

[broncobuddha]

Yes it's the kit I got from Tom's.

I'll probably call them because they need to know if multiple users are having issues.

Thanks for the link.

For those who've replaced the relays you've had no more issues?

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[Jdgephar]

Yes it's the kit I got from Tom's.

I'll probably call them because they need to know if multiple users are having issues.

Thanks for the link.

For those who've replaced the relays you've had no more issues?

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As with any cheap, foreign sourced parts, probably best to keep a spare handy. If/when mine go, I have the standard Bosch style that I will rewire mine to use.

Also, as a quick test, you should be able to swap the two relays. Low beams should then work, and then you should have no high beams until you replace the bad one.
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[broncobuddha]

I thought I tried swapping them tonight but I might have gotten them mixed up. Still only high beams. Is it likely they both went out?

Your link has 40a relays where as the ones in the kit are 30s.

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[broncobuddha]

Update.... I found my issue.

It's not the relays. As suggested I turned the high beams on and pulled each relay until they went off. Swapped them and the hi beams stayed on regardless of which relay I used. Plus with the hi beams off and the light button all the way out/on when I plugged either relay I to the low side of the harness I could hear the relay clicking to engage.

So...the problem? Inline between the relay harness and where they both terminate to the positive side of the battery there are 15 amp blade fuses. The low side fuse was blown. I put the still good hi side fuse in the low side and now the low beams work.

I only have a 30 amp blade fuses lying around and tossed it in the high side and the his work now too.

Is there a concern having that big of a fuse there? I mean I can go get another 15 but it blew for a reason and might again.

In any event I found the primary issue. (Underlying yet to be determined)

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