Wiring Turn Signal - Headlights

[apexted]

Hi All,

I am hoping I can get some guidance from the FFR Forum on wiring the turn signals and headlights on a MK4 Cobra with a RF haness. The engine is a Gen 3 Coyote. I also have the Russ Thompson turn signal installed. The issue is, I had everything wired up according to the RT schematic and when I turn on the turn signals the hazard lights come on. The high beam lights work but not the low beam, go figure. Moving forward I removed all connections diodes and relays from the RT schematic and wired the car according to the FFR Schematic leaving out the RT turn signal. This did not work either, I can get high beam when toggling the high beams and no lights when toggling low beam. Hazard lights come on when using the turn signal toggle. I am thinking there is an issue with the fuse box and relays. Has anyone else had this issue? I am sure I am missing something simple but cannot seem to figure this out. Any help input is greatly appreciated.

Thanks,

Ted

[edwardb]

1. Congrats on the Gen 3 Coyote. You're going to love it. But nothing you've described is related to that.

2. Clarification about the RT turn signal assembly. For the turn signal function, it does exactly what that the standard Ron Francis schematic shows (which I'm assuming you have...) using the kit supplied On-Off-On switch for the turn signals. The complication comes when builders use the RT enclosed schematic to add relays to the headlight low/high beam switching using the momentary switch on the RT stalk. This replacing the basic but simple switch provided in the kit. So technically this complication isn't the result of the RT turn signal assembly but rather the attempt to enhance how low/high beam switching is done.

3. The turn signals, hazards, and headlights are all on separate circuits. So any interaction between the three is typically some type of wiring error. Based on similar questions and problems found, these are the two places I would check first:

- How do you have your hazards wired? Are you using the kit supplied double pole switch? It has to be wired exactly like the RF schematic shows. The pink hazard wire goes to two poles on the switch. The left and right turn signal wires are on separate poles on the switch. If you don't have it wired exactly that way, it will interact back to your turn signals. Builders get into trouble when trying to use a different switch, e.g. a single pole switch (where diodes are required) of just wire it wrong.

- Check the wires on your front and rear harness connections. Specifically those for the headlights and front/rear lights. Check to make sure the wire going into one connector is exactly the right wire matched on the other connector. There have been several cases where builders found wires that were switched around in mating connectors. Causing all kinds of weird issues.

[apexted]

Thanks for the input on double checking the wires to all the lights. First I found that the low beam wire connector from Ron Francis was not making a connection. This took a while to find, had to ohm it out. The turn signal wires were wired correctly in at the harness but here is the problem. Instead of the two round tail lights I have the rectangle tail lights which has 3 wires, there is 4 wires going to the tail lights from RF. White=ground, Red=stop/turn, Black=tail for the rectangle lights. Upon wiring the lights I combined the turn and brake wires to the Red wire which fed back to the harness. Moving forward how could I wire the light? Would it be possible to put a Diode on the turn signal wires? Not sure if this would work.

[edwardb]

Thanks for the input on double checking the wires to all the lights. First I found that the low beam wire connector from Ron Francis was not making a connection. This took a while to find, had to ohm it out. The turn signal wires were wired correctly in at the harness but here is the problem. Instead of the two round tail lights I have the rectangle tail lights which has 3 wires, there is 4 wires going to the tail lights from RF. White=ground, Red=stop/turn, Black=tail for the rectangle lights. Upon wiring the lights I combined the turn and brake wires to the Red wire which fed back to the harness. Moving forward how could I wire the light? Would it be possible to put a Diode on the turn signal wires? Not sure if this would work.

Good progress on finding the headlight issue. For the turn signal and rear lights, you need to use a trailer adapter. I personally haven't installed/wired a build with one. But have seen multiple builds that have and my understanding is this is what Factory Five is supplying with their new one-piece lights. There are many different buying choices. This is an example: https://www.amazon.com/iit-16690-IIT...832167&sr=8-17.

[apexted]

Yep you are correct, I did find that part in the garage it was sent with the lights but I had no idea what it was for as there were no instructions for the light install. One other issue I am having is the horn is not working, I can hear the relay clicking but no power to the horn. This is awesome thanks for the help!

[edwardb]

Yep you are correct, I did find that part in the garage it was sent with the lights but I had no idea what it was for as there were no instructions for the light install. One other issue I am having is the horn is not working, I can hear the relay clicking but no power to the horn. This is awesome thanks for the help!

Horn should be relatively easy to troubleshoot. If the relay is clicking then the switch side would seem to be working. Not sure which side of the relay the fuse is on (not illustrated in the wiring diagram) but check the fuse. There's one for the horn only. Follow the wires through the front harness. There is a +12V and ground provided for the horns. It's a battery circuit so should work with or without the ignition switched on.

[apexted]

Found the horn issue, another bad crimp at the horn connection. Have all the electrical now working including the RT turn signal. Waiting for parts from McMaster to clean everything up. Thanks for the help!