[james]

I have a 2002 astro awd the rear heater blower will not spin, any speed. My question is does anyone a correct wiring diagram? I looked in my haynes book, It shows dk blu, red, wht from the switch to the blower. In real life I have a green, black, white, two greys and light blue leaving the swich.

 

[ihatemybike]

I'd look at the resistor before the wiring. Try hooking a multimeter up to it.

 

[james]

I checked all three wires on top of the resistor with the rear heat switch in all three positions....nothing. Since the three wires on the blower resistor are different color/gauges than the wires on the switch I am going to assume there are relays somewhere. I traced the wires from the rear blower to the drivers left foot area, now they travel up and IT'S A FREAKING MESS.

 

[sfeaver]

There is a relay under the hood that controls the rear heat feed, also does the rear air, its marked A/C Relay. Does the rear a/c blower work? If not, check that relay, and heater fuses. The fuses are HTR-A/C (which also affects the front), and under the hood there is a RR HTR/AC 30a fuse.

Comes from that relay into the Aux Heater switch with an Orange wire. Lo speed is dark blue, medium is red, and white is high speed. Grey/black poweres the solenoid under the hood, and grey and black are for the light.

At the rear heater resister, A is position A, White is position B, which also goes direct to the fan motor. C is the dark blue wire. Yellow is hot to fan motor, black is ground. The resister pack also has thermal overloads, maybe they are gone? You would have full speed thogh.

With a volt meter you can trace through and see what you have. If the wiring colors dont match, that could have been added after the van was built maybe? I dunno, but hopefully this gives you something to go by.

I would probably work from back to front and see where you lose power.

Scott

 

[sfeaver]

There is a relay under the hood that controls the rear heat feed, also does the rear air, its marked A/C Relay. Does the rear a/c blower work? If not, check that relay, and heater fuses. The fuses are HTR-A/C (which also affects the front), and under the hood there is a RR HTR/AC 30a fuse.

Comes from that relay into the Aux Heater switch with an Orange wire. Lo speed is dark blue, medium is red, and white is high speed. Grey/black poweres the solenoid under the hood, and grey and black are for the light.

At the rear heater resister, A is position A, White is position B, which also goes direct to the fan motor. C is the dark blue wire. Yellow is hot to fan motor, black is ground. The resister pack also has thermal overloads, maybe they are gone? You would have full speed thogh.

With a volt meter you can trace through and see what you have. If the wiring colors dont match, that could have been added after the van was built maybe? I dunno, but hopefully this gives you something to go by.

I would probably work from back to front and see where you lose power.

Scott

 

[ihatemybike]

Is there power to the switch in the dash?

 

[james]

I have 12 volts on the white wire at the "REAR HEAT" switch when I turn the key on. the rear a/c fan works fine as does the front blower.

 

[sfeaver]

Ok, turn the switch on high and see if any of those wires has 12v coming out.. Sounds like the colors dont match, but if you try each position of the switch and see what wire its on you'll know what they are in the back. Sounds like the Orange wire is white on your van, so that means the relay and fuses are okay. Now you just have from the switch back to diagnose.

 

[james]

OK its story time............I've been working on cars almost my whole life, I got pictures of me sitting under the hood at 3 yrs old. I went to college full time for 2 years I took all their courses for electronics engineering, So I could fix car stereos and amplifiers. At work I deal with single and three phase power, 277v, 480v, 12500v (tweleve thousand five hundred). I am customizing my 2002 Astro van as a show car. I wired in a two-way paging car alarm with remote start. I start the van with no key in the ignition, So I had to learn how GM PASS-LOCK II worked and defeat it. Yeah its hot-wiring a computer controlled car. and movies like GONE IN 60 SECONDS........are so fake You don't do it that way.(i'm refering to new cars with computers) I'm not going to talk about this anymore because I you never know who's reading. BACK TO THE POINT....so I was tracing the wires from my rear heat switch behind the dash. It's a pain because I have a 12" touch screen monitor I fiberglassed into the dash (it contols the wireless internet laptop computer under the passenger seat) I'm laying upside down, got my right hand in the dash up to my elbow, a shoplight in my left hand .....................Guess what I found.??????????????????????????????????????? A connector stuffed way in the back with a RED, WHITE, BLUE wire!!!!!!!!!!!! Yeah my dumbass had the wrong plug connected to the rear heat switch!!!!!!!! After I thought for a minute I remembered I removed the rear windsheild washer switch, as I removed the wiper when I shaved and welded all the door locks, and door handles. so thats why there is an extra harness. ANYHOW...thanks for the help guys.