mustangGT86_05

Ok so I ran into the issue of upgrading my headlights and after a while the lights flicker in and out. I have 4 relays ready to be installed but have a slight issue. When I have my dims on, I get a very slight glow of the brights. Considering it doesn't take much at all to power a relay, I find this may be an issue. I looked up a diagram on veryuseful.com but I always find their diagrams to lack key info and it doesn't seem to display the individual bright bulbs.

So, the only thing I can figure is for some reason the power flow is feeding back through the brights circuitry just not sure why. The thing that gets me is I did the same upgrade on my 86 grand prix and it does the exact same thing. I have also replaced my dimmer switch, the old one was worn but still have the same effect.

I think if I cut those wires to hook to relays it would eliminate the issue since if I am thinking right it wouldn't allow the headlight current to back feed through the other wires, but I also don't want to go altering my wiring and be blinding other drivers with no control if I'm overlooking something. So does anyone have any other input? I am ready to get this done asap so any input would be great.

mjr46

you have a bad ground or connection somewhere and or bad lamp, I have a 85 and have never seen such an issue occur on 85-86 in which relays are needed, on 87 and up gt models with fog lamps it was necessary to use a relay for the fog lamps since wiring for such wasn't heavy gauge enough and cause a lot of fuse box grief

ttocs

I would guess your switch is going out personally, arn't they known to go bad?

Did you upgrade to hid? What wattage did you get(35-55)? To put relays in you only need one relay for the low beam, one for the high. You could use one per light I guess but it is 2x as much wiring and will not buy you anything in the end. I run 3 relays on mine with HIDs but the 3rd is for the driving lights(94gt).

Look at the bottom of the relay and you will see small numbers next to the pins to mark which is what. Tear the relay apart into two parts, the coil and the switch. The coil is what you need to put power on, in order to activate the relay to make it actuate/click. Its pins are 85 and 86 and it doesn't matter if you put power on one, or ground on the other its your choice.

The switch is what you will use to power your lights and it uses the remaining 3 pins because it has a normally open contact between pins 30 and 87, and a normally closed contace between 30 and 87a. In this case we will use the normally open pins 30 and 87 which will become common when the coil gets power. Now take a fresh power source(can be constant or switched if you want but an ignition will be better) and connect tha wire to either one of those pins, again it doesn't matter. Now take the other pin of the normally open contact that we did not use and connect that to your light for power.

It is important to fuse the power wire that is connected to the switches contact, the amperage rating will depend on what lights you are using.

mustangGT86_05

No the lamps are fine, and I don't think its a ground but never know. What got me is, as I said, when I did it on my gp it started doing the exact same thing. Best bet I found looking it up was to do relays, but hell maybe I'll try to replace the switch. Its just if I have it on dims for about 45 minutes they start flashing in and out, if I put brights on I'm lucky to get 2 minutes. I also don't recall it doing this with my sealed beams, now I am running of course h4 and h1 bulbs.

And thanks ttocs, I know how to wire them just want to make sure my brights don't want to pop on with my dims. I also am not running hids.

mustangGT86_05

I did a little more research again, see some people saying switch can't handle upgraded bulbs, but at the same time seems if I replace it I will end up with the problem again after a while. Some say it would be best to do a relay set up too. I guess I'll give the switch itself a shot but if it comes back then the relays will go in.

Now to go back to my original question, any reason why the dims would shine lightly with the dims on? Betting its as I suspect but other possibilities are welcome so I can double check them