Nismoz

Hi fella's new here but own a 3rd gen for 25yrs and hope the knowledge here could help without me tearing the car apart.
My iroc pops the istr panel fuse when pulling on the tail light switch only if the tail light fuse is in. The tail lights all seem to work fine and do not pop their fuse at all. although the istr panel fuse will not pop if the tail light fuse is not in or if the switch is off.
is their a circuit to something specific that gets power from the tail light portion of the switch that feeds something on the istr panel fuse or backwards of that? Thanks

Nismoz

just checked and green,white,brown wires are the only wires that show continuity to ground on the headlight harness at switch

John in RI

iTrader: (167)

Here is the Wiring schematics for the 85 Camaro.





The Tail Fuse feeds power to the light switch and the Light switch feeds power to the INS fuse. No Tail Fuse - no power to the INS fuse.

The INS fuse should ONLY get power when the HEAD or PARK lights are active. The amount of voltage current is variable based on the rheostat dimmer on the light switch.

I'm going to GUESS that your Light Switch terminals are either burnt/melted,... or there is a short to ground at the Rheostat of the Light switch.

Regardless of what I think,.... these schematics are pretty much should be all you will need to find the problem; Good Luck !

Nismoz

Thanks that diagram helps greatly, I replaced the switch as the inductance wire wld glow red right before fuse popped...didnt stop the green wire from fuse box to body from showing continuity to ground thou.
My car doesnt have the center console clock and light, only for the auto selector(yea sucks it aint 5 spd)aftermarket radio functions fine on factory harness adapter and removed doesnt stop the grounding either.
where is the control light, in the switch?
I have the cluster,radio and light switch all out atm and still grounding at the green wire in istr panel fuse slot going to body not from switch to fuse block.

sofakingdom

iTrader: (1)

Trying to measure the resistance between the green wire and ground will always show conductivity. When you do that, you're actually looking at all the tail & parking light bulbs, through the dimmer rheostat. The bulbs have very low resistance and will look like "continuity". The resistance should go up however as you turn the rheostat toward the Dim position, up to maybe 10 ohms or something. However, measuring "continuity" on the green wire is inconclusive, and therefore is not a good test of anything. Don't concern yourself with that. Instead:

Take out the INST LP fuse, turn on the parking lights, turn the dimmer to all the way bright, see if the TAIL fuse blows. If it does, the green wire is chafed or pinched somewhere. This is not likely at all but needs to be checked.

If the TAIL fuse didn't blow, check the voltage at the INST LP fuse terminals, with the parking lights on and the dimmer all the way bright. One terminal will be at 12V, the other will be at ground. The one at 12V is the dk green wire; the one at ground is the grey wire circuit.

Measure the resistance between the grey wire terminal of the fuse and ground. Most likely you'll see a dead short, that is, less than an ohm or so. If the whole grey wire circuit (the instr lps) was good, you would see several ohms; maybe 4 or 5. If it's a short (less than 1 ohm) then you'll have to trace all the grey wires: this is almost certainly what you'll find.

Since you have an aftermarket radio, I'd suspect to a probability greater than 95%, that the problem is how the radio is wired. Find where the grey wire hooks up to the radio harness and see what Skillet did to hook it up.

Come back and tell us what you find after making those checks. Maybe take a good clear photo of the junction where Skillet spliced the aftermarket radio harness into the factory wiring.

mikeceli

iTrader: (2)

"Sofakingdom", Is "Skillet" the same as "Joe MaGee"? (The guy we blame for cobbed up work).
'

Great info in your post, as usual!

John in RI

iTrader: (167)

+1:

I read that the radio was removed,.... while the radio is removed and all other things are connected as expected ( everything installed, plugged in, all fuses installed, etc) ....... did the ISN fuse pop ??

Can't count how many times an aftermarket radio installation has caused problems !! At the radio: The GREY wire is voltage for the backlighting and the BROWN wire is battery voltage signal wire from the headlight switch. The factory radio gets the switched voltage from the BROWN wire and reduces JUST the digital display,... then the GREY wires feeds the backlighting. Most aftermarket radios don't need the GREY wire.

As you can see in the schematic the light switch mostly deals with sending voltage to other things. The only time GROUND is passed thru the light switch is when the dimmer is adjusted all the way to "up" to activate the courtesy lights. ( should only pass ground thru the WHITE wire to the courtesy system.) Be sure the courtesy lights are turned OFF when probing your wires.

Schematic for the radio : ( from an 84 shop manual,... your ORANGE wire might be different at the fuse box. )

sofakingdom

iTrader: (1)

I think they're brothers, brothers-in-law, and both 1st and 2nd cousins, all at the same time.

Nismoz

Im guessing ur some type of moron or something?

Anyway To the One that actually helped...yes I know bulbs are a shorted circuit, I had done exactly as u describe before seeing ur mssg just now. But with every bulb removed on that circuit. Turns out the resistance went away after pulling the a/c controls light wire. Replaced fuse and all worked fine again after putting 26 i think bulbs back in and the entire enterior back together. Thanks again

sofakingdom

iTrader: (1)

Who me? No, I'm not near as bright as those 2 inbreds.

All that aside, what's wrong with the AC control head backlight? Why was it blowing the fuse?

Nismoz

sorry im not even sure what that quote/sig or whatever it is means but anyway.
unfortunately I cant for 100% for a fact say and that part sucks since Im a maint engineer and facts mean alot working on multi mill dollar equipment. I never could find a definitive cut in the coating of the wire although I didnt pull it completely from the dash only that my meter stopped beeping when I pull on those wires and I couldnt make it repeat continuity. I only resoldered the wires on the b&m shifter light indicator and heat shrink them. If the issue shows up again at that point Ill pull that circuit out the dash to look where I couldnt see yesterday.

sofakingdom

iTrader: (1)

​​​​​​​Which one?