Dash lights out

fred495us1 · #1 08-01-2005, 10:40 PM

Car info: 92 ford crown vic
standard gauges
pioneer HU DEH-3600
Amp and subs

OK problem started about 2 weeks before i got my HU, amp, and subs installed. Backlights for the guages went out once and then came back on by themselves. Checked fuses after the first time and they were all good. All of the other lights on the dash work. Got everything installed and about a week later i noticed that the backlight was out and it would not come back on. checked the fuses and two were blown. so i started messing with switches and noticed that one of the fuses only blew if i turned the headlights off. If they were on the fuse didn't blow. the other fuse blew as soon as i put it in( there is alot of current flowing through that circuit because it will melt the pegs on the fuse before it blows it). I figured there was a short in the headlamp switch so i replaced it.( didn't help same fuses still blow and no backlight) so i started to suspect the HU install since it went out so soon after i got it installed. I took out the HU and noticed that there are three wires on the harness that they did not use(got it installed at a car audio shop) and connected them all together and caped them off. two of the wires are marked one is Illum. the other is illum. dimmer ground the third is not marked but it is a orange wire.

Should these wires be connected together and could this be the cause of the problem. Or do any of you have any other suggestions about what my problem could be

long post but i read alot of threads where people don't give enough info and nobody can help them.

BTW i have read some of the other threads about the backlights being out but none of them seem to fit my problem. in all of the threads i read there was no problems with the fuses

L|_|da · #2 08-02-2005, 11:24 AM

what are the fuse names? it should be listed somewhere around the fuse box, usually on a piece of paper glued to the fold down panel, and which one i melting? i would try disconnecting you headunit[take the plug out from the back of it, you shouldnt have to disconnect all the wires]

jsut to clarify, its the backlights to your stock gauges, speed, fuel, odo, etc. correct?

fred495us1 · #3 08-02-2005, 06:47 PM

the fuses are #6: chime, radio illumination relay, ACC blower control and, Illuminated entry
And #11 Instrument panel illumination(cluster, ACC, rear window defroster switch, radio, antenna switch, heated windshield switch)
the #6 fuse melts.
also i forgot to say this in the first post the illumination for the ac switches doesn't work either.
yes it is the backlight for the stock guages.

4trackmixtape · #4 08-02-2005, 07:14 PM

I had the same problem after I had a h/u installed (note to self - always do your own installs). The ILLUM wire was not capped off and kept shorting out all my lights when I would take a hard left. If you cap the wires, you shouldn't have the problem anymore, at least from the h/u. g/l

fred495us1 · #5 08-02-2005, 08:51 PM

the illum. wire is caped off but it is connected to two other wires(see 1st post).

PaulD · #6 08-03-2005, 01:14 PM

try taping them off seperately and see what happens

the illum lead is so your headunit will dim a little when the headlights are turned on

never heard of an illum dimmer ground on a headunit

orange sounds like a switched 12V lead

does the headunit actually work/ turn on ?

fred495us1 · #7 08-03-2005, 05:37 PM

The head unit Works fine and the wires that i am talking about are the wires that are coming out of the
wire harness that connects to the factory harness.

I separated the wires and turned on the switch and the fuses didn't burn so i reconnected them and they burned.
right now i have the wires taped off and my HU out.
I'm not sure if the backlights have a sensor and only work at night but they are still not coming on. I guess ill have to check the wires and see if they are getting any power.

Well at least the fuses aren't blowing anymore and i know what was causing them to blow.

to whoever installed my HU this is all i have to say to them

fred495us1 · #8 08-03-2005, 10:57 PM

i figured out what the problem was. two of the wires were supposed to be connected so that they would complete the circuit and the backlights would come on. the other wire made it short out and blow the fuses. I connected the two wires and capped them off and i pulled the other wire out of the harness.( It was a useless extra wire the farcory harness didn't even have a connector for it). Now the lights work perfectly and haven't blown a fuse yet.

I told my dad to let me do the install myself but NOOOOOO he said "i'd rather you have it installed at the shop. If you do it you might mess up the WIRING"

he payed for the install so no loss on my part

PaulD · #9 08-04-2005, 01:10 PM

unfortunately, some installers are not that knowlegeable

fred495us1 · #10 08-04-2005, 07:54 PM

WTF is wrong now?????

now the wires are heating up and a buzzer turns on when I dim the backlights. The Headlamp switch also heats up. The wires heat up faster when the backlights are dimmed.

The lights work but the wires are heating up could this be because they are not connected to the HU

PaulD · #11 08-05-2005, 12:59 PM

I have never seen what you are describing, does the manual not say anything about how to connect it ?

fred495us1 · #12 08-05-2005, 01:14 PM

All i have is the box for the HU I dont have the manual. The HU is a pioneer DEH-P3600 Two of the wires that come out of the harness for the HU have been cut off can anyone tell me waht these are for.
the wires are a Yellow and black wire and a Orange and white wire.

fred495us1 · #13 08-05-2005, 06:34 PM

Well i connected the wires and messed with the lights for a while and i managed to make it work. If i leave the backlights on and turn them all the way up the wires and switch don't get hot so i figured what the hell i'll just leave the lights on all the time.

L|_|da · #14 08-08-2005, 08:04 AM

this is a perfect example of why your do your own shit, if your paretns wont let you, tell them your taking it to a shop, goto a friedns house and do it. thats what i did when i installed my HU and amp.

but yea, thats a weird fucking problem, this is totally new to me.

dewmiester · #15 08-10-2005, 05:54 AM

i had the same problem when i installed my JVC h/u...a fuse for the dash lights was blowing...after a lot of rewiring, i realised the original earth wire,when connected to h/u, would blow the fuse wen i turned the lights on... so i pissed the old earth off(just put tape over the end) and made my own earth just for the headunit....no problems since

POST REPLY TO THIS THREAD