70 Mach 1 turn signal issue

[miketyler 15]

I have got all my lights wired up now and found an issue yesterday. My turn signals dont work if the parking lights or head lights are on. I do have LED bulbs in the rear but blinkers work fine with headlight switch off.

 

One other thing I noted is that the front parking lamps seem unusually bright like perhaps both filaments are getting power when I turn on the headlights.

 

Most everything is new including new Alloy Metal headlight harness. Under dash harness was refurbed by Midlife.

Edited October 15, 2012 by miketyler

[LoneWolf2U 136]

Check the front parking lamps for reversed wiring at the connector plug.

[miketyler 15]

I will check but they have rubber molded connectors and only go on one way. Also meant to add that I disconnected the front park/turn signal lights and made no difference.

[miketyler 15]

I put the incandescents back in the rear and all is working although they do flash slow. I guess it has to do with the loading that changes when the headlights and park lights are on.

 

Any recomendations on an LED flasher that works? I wouldnt have thought finding an LED flasher would be a balancing act but after doing a search have found a few other cases where the LED flasher failed to work. I have a few extra LED flashers I had bought for the Cuda but they are three lug. They dont seem to work when plugged in to either side and grounded properly either.

Edited October 17, 2012 by miketyler

[Burn 14]

Hey Mike, I had my harness redone by Midlife too and ran into your same issue. It was weird, but my issue was resolved by a new "Red Top" Optima battery. Make sure your battery is fully charged.

 

Jim

[miketyler 15]

I am running a new Optima actually and just charged it up using a battery tender.

[jag 10]

Mike I had just about the same problem when I got my 70 Mach. Turn signals worked until I put the lights....then they would not work. The problem was the flasher. Get a new flasher and see if that fixes the problem.

JAG

[miketyler 15]

Suppose you mean standard type flasher? I tried an LED flasher but made no difference. I will try that and report back.

Edited October 17, 2012 by miketyler

[CarZombie 25]

Try cleaning the fuse box terminals. I had problems with my turn signals and flashers and that was the problem, dirty 40 year old terminals.

[danno 128]

Mike, the front bulbs could be a clue. Take out the yellow bulbs and put in clear ones so you can see the filaments. Are both filaments lighting up with the turn signals? If so, that is a problem. The LED flasher should work with the front bulbs removed completely, but I am not sure about that. My guess is the case of the LED flasher MUST be grounded.

 

You can find out if the connections to the flasher are bad if you have a voltmeter. With the turn signals on, measure the voltage on the battery. Then put the voltmeter probe on the input wire to the flasher, it is the orange/yellow wire I think. It should have about the same voltage (maybe a little less) as the battery. If it does, your wires, fuse, and connections are ok. If it is 0.5 or more lower, that is a source of problem also.

[miketyler 15]

Danno and Mach1Rider were right. The front lights were it. I bought these repop front park/turn signal assemblies from a guy over on VMF when I first bought the car a couple of years ago. They were brand new and never used but both were wired up backwards!

 

I hated to cut and splice them because the assemblies look beautiful but it was either that or hack up my new Alloy Metals headlight harness. Once I did that, I put the LED's back in the rear and all work now with headlights on or off. Also notice they blink and alternate with the side markers. The flash rate does slow down when the headlights are on but still doable. I might add the heat sink style resistors to see if they improve the speed at some point.

 

Thanks for the help on this one. :thumbup1:

Edited October 19, 2012 by miketyler

[danno 128]

Great, now on to your next task. It seems like you have so many issues, and you keep at it, one at at time. I can't wait to hear the next one!

[miketyler 15]

Indeed - and there are many more tasks ahead. Still need to run the wires for power mirrors, power windows, power door locks, speakers and I can finally close out the door panels and put the instrument panel in!

 

I move so slowly on this and things take me forever to complete to my satisfaction. This January will be three years now I have been working on this. I found this photo recently when I pulled it out to swap cars around.