Alice mod/HID headlights= blinkers dont work when headlights on

[kat]

My blinkers worked prior me messing with them on my '76. I did the Alice Mod first and checked if they worked and all was good. Then I replaced headlights with HID and have the upgraded wiring harness with them. Headlights work great.

Headlights off= blinkers blink but seem not very bright
Headlights on bright or dim= Running lights seem to bright and blinkers dont work.
Rear blinkers/tail lights are fine.

Maybe my eyes are playing tricks with me with the brightness of front blinkers/parking lights. Could just be the clear lenses. Seems I have a wire crossed but everything can only plug one way.

 

[Broncobowsher]

I don't remember exactly what the Alice mod is anymore.
But traditional lights are not polarity sensitive. Backfeeding power through the elements isn't a problem.
Fancy new lights are polarity sensitive. When you are expecting to backfeed power through a fairly heavy light bulb, but it is now a diode (or has a diode in the circuit driving it) you will not get the same result.

 

[kat]

I don't remember exactly what the Alice mod is anymore.
But traditional lights are not polarity sensitive. Backfeeding power through the elements isn't a problem.
Fancy new lights are polarity sensitive. When you are expecting to backfeed power through a fairly heavy light bulb, but it is now a diode (or has a diode in the circuit driving it) you will not get the same result.

Alice mod is replacing square front blinkers to oval and recessed.

Broncobowsher I have no idea what you just said...Im electrical challenged.

 

[gr8scott]

Headlights off= blinkers blink but seem not very bright
Headlights on bright or dim= Running lights seem to bright and blinkers dont work.

Sounds like you might have the wires crossed.

 

[gnsteam]

When I did the Alice mod on my 76. I purchased new 66-68 turn signal sockets from Jeff's Bronco Graveyard. After the install I had a similar issue. The problem was the new sockets Even though the sockets had pre attached plugs. the wiring was reversed at the socket. So I had to cut the wires between the socket and plug and reverse connect the wires. Problem solved. This may or may not be your issue but its something to try.

 

[kat]

When I did the Alice mod on my 76. I purchased new 66-68 turn signal sockets from Jeff's Bronco Graveyard. After the install I had a similar issue. The problem was the new sockets Even though the sockets had pre attached plugs. the wiring was reversed at the socket. So I had to cut the wires between the socket and plug and reverse connect the wires. Problem solved. This may or may not be your issue but its something to try.

I didn't buy the turn signal sockets from Jeff but they are brand new. In my mind I was thinking I had wires crossed but these things only plug in one way and its got me stumped. Ill reverse the wires and see what happens. I wonder if the '69 and up Broncos are wired a little different?

 

[Broncobowsher]

Keep in mind that the Bronco houses don't actually make the part in house. They source them, all from the same place, that has a reputation for building them with the wires crossed.

 

[gnsteam]

Keep in mind that the Bronco houses don't actually make the part in house. They source them, all from the same place, that has a reputation for building them with the wires crossed.

Yep, mine were crossed from the manufacturer. %)

 

[kat]

Dang that is crazy how all of them are built that way. It acts just lets wires are crossed. Ill mess with it this weekend

 

[kat]

Well switching the wires from the new signals worked. Thanks for the help guys. Maybe someone should edit the tech article about this.. I don't know how

 

[gnsteam]

Well switching the wires from the new signals worked. Thanks for the help guys. Maybe someone should edit the tech article about this.. I don't know how

Good to hear this fixed your problem. Now how do we get the manufacturers to correct the issue. %)

 

[toddz69]

A few items of clarification for some issues raised in this thread. Yes, the 66-68 and 69-newer turn signals are wired differently at the plug. They were wired this way from Ford and so there isn't anything to be corrected by the manufacturers - the ones they sell match how Ford initially made them.

The 'Alice mod' doesn't involve replacing the '69-newer housings with the '66-'68 housings/wiring - it's about trimming/re-using the '69-newer housings so no wiring rework should be needed. The article is correct as-written.

Todd Z.

 

[kat]

A few items of clarification for some issues raised in this thread. Yes, the 66-68 and 69-newer turn signals are wired differently at the plug. They were wired this way from Ford and so there isn't anything to be corrected by the manufacturers - the ones they sell match how Ford initially made them.

The 'Alice mod' doesn't involve replacing the '69-newer housings with the '66-'68 housings/wiring - it's about trimming/re-using the '69-newer housings so no wiring rework should be needed. The article is correct as-written.

Todd Z.

Thank you Todd for clearing that up. I was thinking the later models was wired different since I wasn't the only one that had the issue. And after re reading your article you did use the old housing. Sorry if I was out of line. My original housings on my '76 were rusted and just thought I would buy new ones while I was at it. Thanks for the inspiration to do it. I love the new 'old' look

 

[gnsteam]

Thank you Todd for clearing that up. I was thinking the later models was wired different since I wasn't the only one that had the issue. And after re reading your article you did use the old housing. Sorry if I was out of line. My original housings on my '76 were rusted and just thought I would buy new ones while I was at it. Thanks for the inspiration to do it. I love the new 'old' look

Thanks Todd for clearing that up. I purchased the new sockets when I did my upgrade as well.

 

[76YETI]

I bought the conversion kit and then purchased a trailer 2 flat extension, plugs are the same and they reverse polarity. https://www.lowes.com/pd/Hopkins-2-Pole-Flat-Connector-Set/1002650234

Now, I just need a LED flasher to make them and the taillight boards work

 

[76YETI]

Ok. Here we go…be nice as I’m an electrical idiot.
Installed LED boards prior to rewire, added mechanical flasher—everything worked.

New painless wiring harness
LED boards in rear
Added mechanical flashers for both hazards and turn signals
Added Front LED turn signals (66-67)

Rear turn signals work.
Front work if I wire directly to the harness and headlights aren’t on. Turn on lights, front turn signals don’t flash.

Installed 2 prong Trailer plugs and have tried both ways….no turn signals, no hazards. Rear boards work consistently.

I would think the trailer wire would have been the same as cutting and crossing the wires, but clearly not?

I also have HID headlights

What say you…

 

[Broncobowsher]

The front park/turn signals have 2 wires, but 3 connections. There is a ground through the light housing. At least in stock form there is. The stock bulbs are actually 2 light bulbs in one glass package. One wire goes to the park lights, and finishes the circuit by going to ground in the housing. The other wire is the turn signal and finishes the circuit by going to ground in the housing.

The single filament bulb doesn't ground to the housing, it goes through the other circuit to find a ground. So when a turn signal comes on (or should come on) That wire goes to +12V into the bulb. Instead of going to the ground in the housing, it is sent down the parking light circuit. It gets divided up among all the different parking lights on the truck and finds the ground that way.

LED bulbs are tricky. You can't run them backwards, they don't work like that. Old school bulbs don't care what is positive or negative, just a voltage difference across them and they start to glow. But LED is different, the D is for Diode. Diode is a one way check valve for electricity. It can't go backwards to find a ground.

If you really want LED front marker lights, and you want them to work, you need 3 wires. One for each of the two wires in the harness (park and turn) and the third wire is a ground. That is what you have to do to make them work. You are not going to cheat an LED like you could do with a singe filament bulb, which is a hack where it should be a dual filament bulb to start with.

 

[nvrstuk]

Let's toss in another variable.... I just learned this two days ago.

All aftermarket harnesses are wired different than OE harnesses at the flasher unit. Yup, fact here. Most GM aftermarket harnesses are also wired differently than OE

When you install led lights frt & rear you need to add some resistance so the electromechanical unit will turn on/off and flash your lights. You can wire in a resistor to each corner of your rig or purchase a flasher unit designed to work for this application.

When you install an electronic flasher unit (I just installed a Grote) in an aftermarket harness with leds frt/rear (with grd wire) you will turn on your blinkers and nothing. Put a voltmeter on the hot wire to the flasher and it will have 12v. Put the voltmeter on the outlet side of the flasher and nothing. The electronic flasher has diodes in it and power will not flow thru it. The old style electromechanical unit WILL work because it is not sensitive to direction of power flow. Lights might blink super fast but they will work.

All you have to do is swap the two wires in the flasher base so what was the power in wire is now the power out wire and you will have blinkers.

(Thanks Lars)