HVAC defog help - wire colors - LS1 F-Body
03-02-2014, 09:56 PM
#1
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HVAC defog help - wire colors - LS1 F-Body Can anyone do me a favor and take a look at the back of their HVAC controls for the defog switch? Should be a black, brown, pink and gray wires. What position from top to bottom are the colors in? Trying to wire up the defrost button to a non LS1 car.
Appreciated.
Appreciated.
06-02-2014, 07:06 PM
#3
not pulling my dash apart, sorry.
best i can do is tell you what i see in the service manual.
this is for rear window defogger schematics, for 2002.
brown is hot when key in run, coming from fuse block protected by 20A fuse.
black is ground.
orange is "hot at all times, Defog/Seats CKT BRKR 30A" and that connects to the HVAC module where the wiring diagram shows rear window defog relay within the HVAC control assembly in your dash.
now the output wire from this relay within the HVAC control assembly coming out does not have a color specified but it goes to the rear window defogger grid. the other connector on the rear window defog grid goes to ground.
so with that info, if you undo the wires to the rear window defog grid and measure ohms to ground, the one with zero ohms you don't want, the one which should show high ohms or open circuit will be that defog wire- then get some wire leads and probe for continuity between that rear window connection to the pink and gray wires at the hvac module whichever one shows continuity then you know.
my guess is your pink is my orange, and you can measure that easily since it's hot at all times see if you have voltage on it with key off. and the gray wire is the power wire going from the internal hvac module relay to the rear window grid.
best i can do is tell you what i see in the service manual.
this is for rear window defogger schematics, for 2002.
brown is hot when key in run, coming from fuse block protected by 20A fuse.
black is ground.
orange is "hot at all times, Defog/Seats CKT BRKR 30A" and that connects to the HVAC module where the wiring diagram shows rear window defog relay within the HVAC control assembly in your dash.
now the output wire from this relay within the HVAC control assembly coming out does not have a color specified but it goes to the rear window defogger grid. the other connector on the rear window defog grid goes to ground.
so with that info, if you undo the wires to the rear window defog grid and measure ohms to ground, the one with zero ohms you don't want, the one which should show high ohms or open circuit will be that defog wire- then get some wire leads and probe for continuity between that rear window connection to the pink and gray wires at the hvac module whichever one shows continuity then you know.
my guess is your pink is my orange, and you can measure that easily since it's hot at all times see if you have voltage on it with key off. and the gray wire is the power wire going from the internal hvac module relay to the rear window grid.
06-02-2014, 07:12 PM
#4
also the connector end view that plugs into the back of hvac control assembly in dash, has 4 wires. looking at the end of the connector the diagram shows
-| -| -| -| for pins that go A,B,C,D from left to right.
A = orn = battery positive voltage
B = ppl = rear defog element supply voltage
C = brn = ignition 3 voltage
D = blk = ground
this is all out of the 2002 GM service manual for camaro and firebird.
-| -| -| -| for pins that go A,B,C,D from left to right.
A = orn = battery positive voltage
B = ppl = rear defog element supply voltage
C = brn = ignition 3 voltage
D = blk = ground
this is all out of the 2002 GM service manual for camaro and firebird.
