No bright lights or dash lights...

[Toneyb35]

My dash lights just stopped working one day and my bright lights never worked as long as I've owned the car. I have repaired or replaced all the bad wires I saw inside the dash. I've replaced the headlight switch and harness. I have a 140mph dash cluster that I want to install or just replace the speedo and tach, but I want to make sure I get all wiring issues done before I go any further. I don't know how to check any switches so specifics would be greatly appreciated.
Thanks in advance...

 

[HISSIN50]

For the dash lights, I'd check the instrument light fuse. It's a 5 amper.
If that's ok, go to the back of the headlight switch and check for output power from the switch.

For the brights, check the output at the MF switch.

 

[Toneyb35]

The fuse is good. Which terminals are the output power for the respective switches? Am I to use a test light for these tests? I have excess to a multimeter but not too knowledgeable in its use.

 

[Toneyb35]

Just rechecked the fuse and it was blown. I replaced it and it blew again. I have the dash removed and don't see any obvious issues. Is there somewhere specific to check?

 

[HISSIN50]

Which fuse was blown?

A test light will suffice for most testing. It's less confusing than using a meter.

 

[Toneyb35]

The fuse was labelled #13 instrument cluster 5amp. I replaced it and as soon as I turned on the lights it blew almost immediate.

 

[HISSIN50]

Start tracing the dimmer circuit, looking for a pinched wire. If the radio wiring has been modified (aftermarket deck ,etc) it's common for the radio illumination wire to float around and short to ground. Since your dash was off, all bets are off though.

This might help:

http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxLights-Radio_diag.gif

 

[Toneyb35]

Thanks, I did have a problem with my radio before I took it out. I'll check it and get back to you...

 

[Toneyb35]

OK, I found the radio wire that was grounding the circuit. So, now the fuse is good, but still no dash lights. Does this mean the dimmer switch is bad???

 

[7upstang91]

Do you tail lights work as well? I am not talking brake lights, but tail lights here.

 

[HISSIN50]

In addition to knowing if the marker lights illuminate, put a test light on the dimmer circuit at the back of the headlight switch and see if it illuminates. If it does, run the dimmer down and see if the test light gets less bright as you do this.

 

[Toneyb35]

Ok, I have tail lights and all other lights. The #13 fuse continues to blow (instrument panel lights). I haven't located the culprit yet. What I would like to know is how to (if its possible or probable) to rewire or bypass whatever to get my illumination and brights working.
I don't have a lot of time to give this project as you can tell, but I'd like to be able to do this myself...

Your help is greatly appreciated...

 

[HISSIN50]

You could probably wire the dash lights to the parking light circuit (which, in effect, bypasses the dimmer control).

For brights, I suppose you could wire in a switch so you can turn them on. You could use several relays so the lows go off when the highs are turned on.

 

[Toneyb35]

More relays huh, lol. I think I'll just try to trouble the bright lights to get them to work as expected. As for the instrument cluster, I'm going to fix that problem today one way or another.

Thanks

Toney

 

[Toneyb35]

I found the problem with the instrument cluster. Its the dimmer switch. The wire thats supposed to slide across the wheel, doesn't. I manipulated it to make it do so then the cluster lit up. So I'll be forking out the $100 on 50resto for a new one. Thanks JT

Now that I have the cluster problem solved, I can concentrate on the bright lights. I'm not sure which wire brings in the power, but I didn't get any power on any of them. Which terminal (on the MF switch) to apply power to so I can test the switch?

Thanks a bunch.

 

[HISSIN50]

Red/yellow should have 12V when the headlight switch is fully on. LG/Blk should be the color for highs and red/blk should be the color for lows.