85f-bird

down to the end of it, trying to fix the last gremlins (gremlins = unknowns, known problems aren't nearly as bad) with my 4th gen interior setup. The problem that i'm having right now is with the rear-defrost. And since it's getting close to winter time, and i'm going to be needing it soon, i need to find out what wires are going wehre so i can solve my guages fuse blowing, which of course means that i also loose my TCC lockup feature, along withpicking up the annoying "you're lights are on, but your car isn't"buzz....Sooner i can get that thing done, the sooner this setup will be complete...and i won't have to worry about jumping under the dash etc. every few weeks, any help would be appreciated.

The colors of wires are

(3rd gen)
Purple
Orange
Black
Light Blue
Gray

(4th gen)
Purple
Orange
Black
Brown

i have the gray hooked to the brown 'which lights the "active" bulb in the defroster when you press the button. But, the only time it actually works is when the parking/headlights are on, w/o them, the light bulb won't come on...akward, i think my regular 3rd gen one would light up no matter what, so, kinda curious on that.

Also, the light blue wire has me confused too, can't seem to tell what it is and where it goes on the connector.

I've got purple to purple, orange to orange, black to black, gray to brown, and blue hanging on, right now it's hooked to the black, but i don't think it needs to be grounded, if it did, why not make it black too? Can any of the 4th gen swappers help out with this? possibly look at your own setup and tell give me a clue in, The dash is out of a 96' , cars an 85. Although, i think the guage setup might be from a later model setup, maybe an 98+ car, might try snagging equipment from an older model and see if the wirings a little closer, as we know the ls1 cars are all screwy.

3rdGenSS

ok... im pretty sure this should work for you... mine is a 91 so the actual 3rd gen wires are different, but here goes
3rd 4th
orange it your power in.. hook to orange
purple is out to def..........hook to purple
black is ground................hook to black
lt blue is ip fuse...............hook to brown
grey is dimmer.................not used in 96+ models for def..

hope that helps ya

as for the lights are on but car isnt buzz.. mine did that and i found that the ground wire at the conveniance box was not hooked up.. dumb me lol but once i hooked it up the buzz stopped

85f-bird

thanx camaro...i'm gonna give that a try, maybe later today and see if it fixes my problems (really hoping so, then all i'll have to do is get the front defrost working...ducting) What ya said makes sense, and its amazing that no one else has ever seemed to have this information....so, thanks a million.

85f-bird

problem has changed now....the lt blue wire is now going to the brown wire, unforunately i'm not nolonger getting any power to the rear defrost, checked it w/ a test light as stated in the haynes. apparently the gray wire which is no longer hooked up, was sending power to the defrost.

I originally had the gray going to the brown, and that gave me a power light, along with power to the defrost, unforunately it would blow my fuse. If the gray light blue was going to the ip fuse, then not having it hooked up wouldn't cause that fuse to blow would it?

I'm really confused as to what does what. Hopefully someone has a schematic, or camaro86 can help me out further.

3rdGenSS

now i am confused...... the orange is the pwr feed to the defrost... and the purple is what goes to the actual def... lt blu should be a constant also but goes to ip fuse... i know my 91 had org/blk...prp/blk...pnk/blk.... and blk..... i hooked them to orange, purple, brown.. and did not use grey as the newer do not have a wire for dimming... let me check some wiring info and see if i can come up with something else...

3rdGenSS

just a thought... did you have the key in run? not started but turned so that pwr is comming to the lt blue wire as it is a switched pwr feed?

85f-bird

tested w/ the engine started and car running, was always told that the defrost didn't work in run, only when running. You said you had a pink/black wire, from all the wiring behind my dash, the pink black setup is always a switched 12 volt source, orange (as i have it now) is normally a constant 12 v source.

camaro, see where have u been able to locate the wiring info for the defrost stuff at, as i've had a lot of trouble trying to find that type of infomration? been looking, just not in the right places. I'm going to put a test light on the blue wire today, and find out if it's getting any power at any point and time.

anymore help you can lend would be awesome, and appriciated.

85f-bird

through a test light on the setup this time around, and didn't seem as if i was getting power to anything...akward, since one of the wires has to be a switched 12v sourc,e i should get power even w/ everything unhooked, but, i'm not....and everything should be hooked up as before, except there is no longer a gray wire.

85f-bird

camaro86, hopefully you'll get back to this one. Im working things out slowly, but still am stumped. heres the deal.

Orange is switched 12v, that's been confirmed now. finally found out my test light wasn't connected well a couple times, then i started back probing, and also found out that my stupid connection on the 12v wire wasn't that good, improved it, and bang, light w/ power to on, not running.

The gray wire is giving me poewr when the lights are turned on, it was connected to brown, with it was connected, i could get the defrost to come on.

I connected the blue wire to brown instead, no power coming from blue (confirmed).

Purple is indeed the power to the defrost itself, and i get power with the gray wire hooked up.

Now we get more tricky. With the gray wire hooked up, and the defrost powered up, if i remove the gray wire the system stays on. Then, if i touch the light blue wire to the brown wire (where the gray was) the system will turn off. Theres power going to the orange the entire time, however, it's not allowing me to turn the system off and on., nothing happens. Im thinking of connecting the orange to the brown, that'll give me power, but it just doesn't make much sense. Question is what does the blue do?

Another thought, my thirdgen defrost had a off button. Could the blue have something to do with that? since the 4th gen version is only one button?

3rdGenSS

ok, im taking it that in your 3rd gen .. your def is not a timed one... as for the wireing, everything i am looking at shows that orange should be constante pwr....of course ppl you already confirmed... grey only has pwr when lights are on because it is the dimmer fuction... blk is gnd of course ..... as for teh lt blue that still has be boggled but i am checking some things...

one thing you could do is run the wires you need basicly you would need to run a constant pwr from 30 amp acc circuit breaker and a switched wire from 10 amp gauge fuse... shouldnt be too hard to do... didnt have that prob with mine since i already had a timed switch in a 91...

85f-bird

might be a problem with the switch difference. My defrost however is timed, it'll stay on for a while, then turns off, always had. Here's something funny though, i've got my ground connected, then i can put purple to purple and pink/black (switched 12v) to orange. If i have all that setup, and hit the button, i get nothing. But, if i touch the purple wire to the orange constant wire, i get my defrost coming on. That's a little bit akward, since it's only supposed to be a switch which should bridge the power. I was thinking the switch was bad, but depending on where i place my power, the switch will either work, or not work. If i run power through the brown wire, the switching function of the button works, if it's not goin there, it doesn't. slowing getting frustrated, and learning a little bit at the same time.

3rdGenSS

ok... tell me again what wired you have from your 3rd gen... and what year is the switch you are using from the 4th gen.. ill do some comparisons with what i have and see if i can post some diagrams for you...

85f-bird

The cars an 85 bird, the wires coming from the dash are....

pink/black (switched 12v)
Black (ground)
Lt. Blue (?)
Gray (lighting)
Purple/White (Defroster)

The dash is from a 96-97 bird. (cant be sure, i didn't pull it) the wires coming off the single vertical connector are

Orange - Large guage wire
Purple - Large guage wire
Black
Brown

3rdGenSS

so you do not have an orange wire coming from the dash? ok...then your lt blue wire should be your constant pwr... make sure the circute breaker is good.. take it out and put it back in.. it will be your pwr acc circuit breaker...

Lt blue then goes to your orange on 4th gen
ppl/whit to ppl
blk to blk
pink/blk to brn
grey not used


see if that will work that should be correct... let me know what you get with it.. again make sure the breaker is reset

85f-bird

so it's nt a fuse, and is an actual breaker? ok, i'll have to take a look at that, and pull and reset it. Its night here now and i'll give it a try in the morning. just want to make sure that it is an actual breaker. Thanks for all the help.

3rdGenSS

yes... your constant pwr will be from a breaker... that should be your lt blue wire... check that and see if everything tests how it should... hopefully that is the problem...

85f-bird

like i had said, i'll be testing it tomorrow....Just for reference, is that breaker the silver thing in the fuse block? it's listed as being ACC , and is the only one that doesn't look like a fuse. If so, i'll be reseting it tomorrow...didn't know we had breakers anywhere on our cars until today.

if that's it, i'll be forever in ur debt. Thanks for all this help so far.

85f-bird

Alright, i pulled the little silver plug from the fuse block (thinking it's the circuit breaker) and placed everything back how it was, still getting no power to the blue wire. I'm going to run a test light to the fuse block at the ACC breaker and see if i'm getting any power, i did notice that it has two fat orange wires coming off the back, so yeh, that's what it is. If the ACC breaker was out, then the radio wouldn't work when turned to ACC right? if that's the case, i've got everythign working, unless things are wired up different than originally thought. If it turns out that the breakers crapped out on me, i'll see if i can replace it today, and get power to that blue wire. Does the blue wire go straight to the ACC or does it go to the defrost and then back to the ACC?

Just curious on that because when i ground the blue wire, the defroster will turn off, which is only a little fishy.

3rdGenSS

no your radio is on a different circuit... do you have the gnd wire hooked up under the dash? there was a blk wire that came from the blck conveniance buzzer box that i didnt have grounded right that caused me alot of problems... check to see if that is grounded right... because the basics should be like this

constant pwr to switch/relay
switched pwr to swtich/relay
pwr out to def
ground

verify that you have those comming from the dash... and i am going to go out an pull my switch and see what is up... ill let you know soon

85f-bird

pretty sure i have all my grounds setup, i'll have to check. I've got power coming from my fuse block at the ACC fuse/circuit breaker (back probed it). Where's the black convience buzzer at? Don't remember unhooking it, but it's possible. I don't have anything to do this evening, so i'm gonna stay at work and see if i can finish this thing off a little maybe we can hunt this thing down today.

I've got those wires, if the blue wire is constant power, then we're good.

have switched power (tests good)
power to defrost (tests good)
ground (tests good)
and soon const. power (gotta get it working)

I'll start working on this around 5, thanks for all the trouble you're going through.

85f-bird

alright, fuse/breaker seems good, power coming from it, no power at blue wire still. Also, check this out. If power from the switched 12v source is applied to the blue wire, the defroster will kick on, as verified by power showing up on the purple wire (along with noise from the defroster activating) , if ground (test light with one end to ground) is connected to the blue wire, the power leaves and the defroster turns off. Can also be confirmed by no power at purple wire. Akward? i think so. Cause if this is the case, then the blue wire is going to the defroster just as much as the purple wire, and apparently isn't going to the fuse block. Wondering if i should run some wire from ACC box, to the defroster switch, to get the two power feeds, one live, one switched, then wire up the purple wire and ground. But the blue wire still has me stumped since it should be in the equation somewhere.

3rdGenSS

only thing i can think of is that in your 85 bird ... maybe you have a seperate relay or something... maybe due to you haveing and actual on/off def switch.... where as the later have a timed switch that automaticly goes off... if that is the case, if you have a switch pwr feed already there..as well as gnd and ppl to def.. then you will only need a constant from the circute breaker... try makeing a jumper wire to test it and see if that works..

85f-bird

alright, i dug my defroster box out from under the passenger dash, here's what i'm getting. we've taken the 5 wire count up a notch, and now it's six. On this box, the wires are as follows.

Orange/Black (large gage, maybe 10) - Constant 12v checked out
Pink/Black (small gage) - Switched 12v checked out
Purple/White x 2 (one large, one small) - Defrost Checks out
Black - Ground (Assuming checks out)
Blue- Unknown, but it's not power apparently as it goes to a differnt connector than the orange ones.

So now we've got 5 wires again, the blue now being the oddball, and the gray is on the other end, but doesn't go anywhere near the defroster. I'm still thinking that i need a power wire to go into the switch in order to get the setup to work, might run the wire from the defroster, or try to trace down the other orange wire that's on the defroster and is now going to nothing (atleast that i can see, everything's wrapped up in 1985 duct tape) But there are two orange (hot) wires, so, once a feed in, the others going out, but where too, my guess is the switch itself, however it's not there....time to go hunting. If you find anything else out please let me know.

85f-bird

Oh, and what i said checked out also, the thing has a timer, it's labled on the silver defroster box thingie, 5/10 min. so, it is timed as i originally thought, but i had that extra off button, even though there was a timer, think it was for you to turn it off early if things had already defrosted, no need in keeping it on.

3rdGenSS

now it is starting to make more sence.... that box is not in the later cars... the switch has a built in timer now... if you try to wire the new switch thru that box i do not think it will work... the way mine is hooked up is direct thru and no box... what i would do is the following....

hook the 4th gen orange wire to the orange/blk at the box
hook the 4th gen purple wire to the purple/wht large wire at box
hook the 4th gen black wire to the black at the box
hook the 4th gen brown wire to the pink/blk wire at the box

then you will be hooked up like it is from the factory on the later cars

85f-bird

ahha, and now we know what's going on. Camaro86, thanks a million for that help, now everything makes sense, just about completely. So, the stupid box isn't actually nescessary, because all it really is is a timer, and infact, all that's needed is the switch, and existing wiring. Beautiful, i took what you wrote and "mocked" up the harness a tad, we'll see if i blow a fuse on the ride home, (might) but i found a constant 12v wire, it was on the same connector, however, it didn't have a wire coming off of it to take it to the switch. I ran the wire from there and into the switch, w/ the car off and ignition to off, nothing happens, with the car to run, and the button pressed, the light comes on, and the defroster comes on. If there's a timer in the defroster switch,then it should switch off the defroster (or cut power) the same way the stupid timer did, and for today this should work. Tomorrow i'll see about getting some more fat gage wire and extend the wires to where i need them in order to get everything working out the way it's supposed to. I'll revive this if i need any more help, thanks a million again, this might help out all those pre 86 f-body guys who are trying to go 4th gen.

With the exception of TPIroc, i think i'm the only other one.....(it's a small enough group of 4th gen swappers as it is...can't wait for show season next year, guys are gonna crappa load)

Like i said, thanks again for all the help. Can't believe this was a post which is flaming now, and there were only two people talking the whole time.

roughskinjrz

i have an 86 trans am but my wires are below, any ideas?

purple/white
blue
gray
black
pink/black

roughskinjrz

this is an old post, but i may have the same problems im not sure, can anyone chime in? whre is the timer located? and do i just cut if out of the picture completely and splice into the main wires?

Firebat

iTrader: (7)

this is the same problem i'm having. I've been looking at schematics for thirdgen and forthgen but haven't found much on 4th gen. All I got so far is black to black and thirdgen purple/wht goes to 4th gen brown.

roughskinjrz

well today im gonna try and cut the timer completely out and wire up what they said above

roughskinjrz

ok so i looked on the passenger side and of course i found a black connector with a silver piece connected to it which im guessing is the timer.

here is my guess.........the wires coming from the rear defrost are wired directly into that timer, and then there are wires coming out of it where the old connector is. so should i just take out the old connector altogether and cut out timer and wire directly in with wires he stated above.

someone must know

Firebat

iTrader: (7)

I just wired it up that way. Completely bypassed the thirdgen connector and wired it in where the timer used to be. It makes the light turn on, I couldn't really tell if it was working...hatch wasn't fogged so I couldn't defog it.

roughskinjrz

cant you hear it in the back if it works? find a way to fog up the hatch window hahaha.

did you cut the timer off completely and tossed it? i was think u could take out the 3rd gen clearn connector in the middle there where it used to be connected...

Firebat

iTrader: (7)

yeah, the timer is gone. I didn't know the rear defrost made a sound.

roughskinjrz

well it is just like defrost on the front winshield right? you cant hear air blowing out or anything?

Firebat

iTrader: (7)

No, the wires glued on the back window heat up

roughskinjrz

oh ok well the guy in this thread didnt write back so i assume it works! im glad you got it working i plan on doin this tomorrow lol