wiring guru's....radio and headlights related. plus i installed fog lights!

[cenok is family]

well i finally got around to installing the fog lights i bought 8 months ago, lol. they look great. i did the wiring fix from corral.net and they work perfect. here's some pics of that...

while i was in there, i decided to pull my dash to trace a wiring issue i've had for a while now. it involves my radio and my headlight switch. the radio works fine when my lights are off, but when i turn them on, the initial flip of the headlight switch causes the radio to cut out, then it turns back on and works normal unless i'm sitting at idle. when i'm sitting at idle, if my rpms drop below about 800rpm, the radio will cut out. since my idle is a tad choppy, it causes it to repeatedly cut in and out and gets reaaaallllyyyy annoying.

a few years ago when i installed my aftermarket radio, i noticed that a previous owner had hacked the original wiring to install a crappy radio that i was replacing at the time. when i installed my new radio, i tried to just use the same wires that the previous owner had used. none of them were original, but some were butt connected to a few of the original wires.

the only thing i can think of is that a previous owner spliced into the headlight switch harness somewhere and it's causing too much of a load at idle with the headlights on. the only two wires i believe that can do this on the radio is the 12v constant (battery) or the 12v switch (accessory) wire. the 12v constant (battery) was hooked up to a factory green/yellow stripe wire and the 12v switch (accessory) was hooked up to a factory orange/black stripe wire. does anyone know what these go to and what would be a better source for both 12v power sources? i also had the 12v switch wire for my autometer oil pressure gauge spliced in with the orange/black wire.

sorry so long, thanks a lot!

 

[HISSIN50]

If you put a test light on the two power wires and turn on the headlight switch, does the test light flicker?

I'd consider just running new wires from the fusebox to the radio.

This might help:

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

Good luck.

 

[cenok is family]

thanks a lot hissin...you're always extremely helpful. i'll check this out tomorrow.

thanks again.

 

[cenok is family]

looking at that diagram, i'm thinking the wire hooked up to the orange/black wire might be the culprit because it looks like it's the only one of the two that has any relation to the headlights. if i just run a new wire to the fuse box, which fuse would you recommend and what should i do with the orange/black wire? just tape off the end of it?

 

[HISSIN50]

You are correct. Or/Blk is tied into the illumination circuit.


I'd use fuse 11. Do you see a yellow/blk wire floating around disconnected in there?

http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif


EDIT: You can insulate (tape off) the or/blk wire if you like. Or confirm that it dims with the lights, and connect it to your deck's illumination circuit if you want auto-dimming.

 

[kendoo130]

Did you check and make sure the body of the car is grounded correctly? (Black) Negative wire at the negative battery terminal that screws to the body-often breaks and often overlooked.

 

[cenok is family]

You are correct. Or/Blk is tied into the illumination circuit.


I'd use fuse 11. Do you see a yellow/blk wire floating around disconnected in there?

http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif


EDIT: You can insulate (tape off) the or/blk wire if you like. Or confirm that it dims with the lights, and connect it to your deck's illumination circuit if you want auto-dimming.

awesome. i think i got it figured out. i ended up tying the acc. wire into fuse 9 which is the heater blower/ac blower. there shouldn't be any problem with that, correct?

i didn't see a yellow/black wire cut but i think i know which one you're talking about. whoever cut the wires originally left that one attached to the factory radio harness plug. i assume you're referring to the one coming out of the top of this plug?

what is it for? do i need to hook it up to something?

thanks a ton again hissin, you've been a major help.

one more issue i found though...i found this wiring mess spliced into a big black/green wire going into my ignition switch. every wire is cut except for a green one that is butt connected to the black/green wire, and on the other end, there is a black wire soldered to what looks to be a factory white wire. there also looks to be a relay and a 20amp inline fuse there. the cut white wire in the pic (the one butt connected to the black/green wire along with the solid green wire) was spliced into my neutral safety switch with a splice in connector so i figured it didn't need to be there so i pulled that part. i want to get rid of all this, where does the black/green and factory white wire go?

the car used to have an aftermarket alarm on it a long time before i got it. i pulled a lot of that wiring out but i wasn't sure if this belonged to it or what. if so, how can i get rid of all of this and where do the black/green and white wires go?

Did you check and make sure the body of the car is grounded correctly? (Black) Negative wire at the negative battery terminal that screws to the body-often breaks and often overlooked.

yeah it's still good

 

[cenok is family]

looking at this ignition switch diagram, it looks like it's supposed to be the "33 white/pink 18g" wire, but it's a 10-12g black/green wire, that's what is throwing me off...

all the other wires on my ignition switch look the same as the diagram, it's just that one.

 

[HISSIN50]

The stereo splicing sounds fine. If you cannot find the source-end of the stock accessory wire, it's no biggie.

Looks like remnants of a starter-kill circuit. Does it connect to your neutral safety switch or clutch safety (interlock) switch?

To be sure, the blk/green wire is not 297, the feed for fuses 2, 6, 11, and 14 (which are coincidentally your radio fuses)?

 

[cenok is family]

The stereo splicing sounds fine. If you cannot find the source-end of the stock accessory wire, it's no biggie.

Looks like remnants of a starter-kill circuit. Does it connect to your neutral safety switch or clutch safety (interlock) switch?

To be sure, the blk/green wire is not 297, the feed for fuses 2, 6, 11, and 14 (which are coincidentally your radio fuses)?

yeah it did! one of the wires was spliced into the clutch safety switch via a splice connector. i pulled that off though because it was tied in with those wires that were all cut.

i looked at the wiring and noticed that the green wire coming off the black/green wire went into a female relay connector as did the black wire that was soldered to the white wire. on the back of the relay connector, there was a jumper wire that just connected the two. basically, it seemed like the black/green wire was connected to the white one through a bunch of unnecessary connections. i cut all the wiring out and soldered the big black/green wire to the white wire and now my car won't start. i'm pretty sure i cut out the clutch safety switch somehow. any suggestions?

 

[HISSIN50]

The two wire jumper connection kinda sounds like how the factory does a jumper for Auto vs 5 speed cars. Autos have a two wire jumper like this because there is no clutch safety switch.

If you hold the key to the crank position, does the clutch safety switch have power going into it? If it does and the clutch is depressed, does the output of the switch have 12V leaving it (IIRC the output side has two wires in it. The input side has one wire)?

You could easily rewire the interlock circuit but it'd be nice to restore it to OEM.

 

[cenok is family]

i got it all figured out and back together now. i doubt it's back to oem, but the wire that was spliced into the clutch safety switch that i disconnected was why i couldn't start it. i cut and soldered the white wire that has a 20a inline fuse in it back into the clutch safety switch wire that was originally spliced into, and soldered the other end back in with the black/green ignition wire. so back to how it was before, only i got rid of all that extra wiring harness that was being used.

everything works perfect now! i have foglights and my radio no longer cuts out ever! it seems like my car is revving a lot smoother as well because i think i fixed a lot of bad grounds and loose wires while i was in there.

thanks sooo much man, you were a godsend. i really appreciate all of your info

 

[HISSIN50]

Well done brah!

 

[cenok is family]

haha thanks dude!