Rear Defrost Problem

Freezman2 · 12-16-2006, 06:51 PM

Recently my rear defrost has stopped working completly...i went in the other night with the multimeter and checked to see if i was getting an voltage, and i am only getting it on one side of the rear window. I know that there are three connectors in the back, and i am assuming that one is for the radio antenna, and the other two are for the defroster for each side of the window. I was wondering if anyone had some more information on this problem...like i said im getting like 6-10 volts on the left side of the rear window....(this is if your were looking from the front seat on the inside of the car) THANKS!

freeze12 · 12-16-2006, 07:15 PM

Either the harness or the module is shot "or both" this is a common problem with the Aleros. The module is located on the passenger side rear. You have to pull off the rear trim piece "next to back window" The module contains both the rear defroster & radio circuit controls.

Module part #22618677 Cost:approx.$111.08
Harness part # 15305949 Cost approx.$29.48

Freezman2 · 12-16-2006, 07:49 PM

Thanks

Vinalero · 12-18-2006, 02:54 PM

I have the same problem, when i press the button in the dash for the defrost, it lights up, but nothin happens in the back, i tested the back with a multimeter too, i'm gettin almost nothin.

This afternoon, as I was doin some wiring in the back of the car, I tried to tear the trims from the back of passenger side. Still couldn't find any module (the trims under the back window).

It's true that i've not taken everything out. Is the module under the top part of the trim, or the bottom part? The only thing i found was some kind of harness almost in the middle of the door, under the trim that covers all the wire that gets to the back.

(I have a 2 doors)

Ty in advance.

freeze12 · 12-18-2006, 10:03 PM

If You are in the back seat passenger side facing the back window the module is located behind the plastic piece to the left of the back window shelf.On a 2 door what has to be removed is the (left side) coat hook,seat belt "Torx Bolt" panel underneath and next to side passenger rear window & the panel next to the back window rear shelf. The panels are held in by push clips...no bolts.It is a pain the first time but after that it is a piece of cake.
This is a half baked pic of where the module is....Part #1 & hope You can make out the back glass & get some inclination on where the module is.

http://www.trademotion.com/schematic.../D/DG99172.gif

Vinalero · 12-19-2006, 01:51 AM

Thank you very much, i can see better now where it is and why i couldnt really reach it.

Also, could it be a problem with one of the relays in the fuse box in the engine bay? My guess is that if it was actually a relay problem, my light on the Defrost switch wouldn't light on.

I'll try to give some review with that and take pics.

freeze12 · 12-19-2006, 03:57 AM

99.9% of the time it is either the harness,module or both. After You pull everything apart look at the plug end for burning....sometimes a little sanding if the contacts will get the defrosters working again. Best bet is a junkyard for the parts as both parts are only available from GM & the price is outrageous!!! Another stupid GM idea like Passlock!

Molson · 12-19-2006, 10:12 AM

Yup, I've gone through 2. Definatly get one from the junkyard. over 120.00 from teh dealership is robbery. I paid 5 bucks at the junk yard.

Vinalero · 03-01-2007, 05:10 PM

just replaced the module in the back. I wasn't even able to get the seat belt off where it is attach to the trim and had to try to unbolt the module by the small room I was able to make by prying the trim.

Let me say that this is a PITA job that way to take the module out, to weld the wires of the connector being in that position (being bent in two, face against back window on the back seat). Also the fkin wire is sooo short. And putting it back is a pain also. All my fingers are screwed.

I also discovered that I suck at welding, or that I have a shitty heat gun lol.

Well it is working now, but I was wondering what was the amount of volts that were goin through the back window. After testing it, I'm getting around 10 volts on the back window.

Also, If my welding isn't perfect, can it start a fire in the back even if I put a lot of electric tape over it? Or, can the connection fails prematurely? (I pulled on both ends of the wire really hard and its not moving, but it seems to me its not a good welding)

freeze12 · 03-01-2007, 05:32 PM

I assume that You are getting 10V with the Ign. key on & the car not running...thats fine. With the engine running voltage is approx. 12.5V
You said: "welding" I assume You meant soldering? As long as it holds and nothing is shorting out its okay as it is better than buying a very expensive back glass!

Vinalero · 03-01-2007, 06:26 PM

Quote:

Originally Posted by freeze12

I assume that You are getting 10V with the Ign. key on & the car not running...thats fine. With the engine running voltage is approx. 12.5V
You said: "welding" I assume You meant soldering? As long as it holds and nothing is shorting out its okay as it is better than buying a very expensive back glass!

hehe, you assumed right

I'm getting 10 Volts with engine off. And yes, its soldering. Sry for my lack of english

. There shouldn't be any short, as I taped that mofo like a mad man. Only time will tell I suppose.

Ty for your follow up Freeze

freeze12 · 03-01-2007, 07:05 PM

Vin.... Your welcome and good job!!!