Rear Windows Defroster
11-24-2003, 10:53 AM
#1
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Rear Window Defroster
As the weather turns colder my non-working rear window defroster is becoming more of an annoyance. Does anyone have any trouble shooting info for the defroster? All the connections look good (I even made some test jumpers to bypass the hatch shocks). Can someone tell me which side is power and which side is ground on the wires that come out of the rear pillars? I have checked the fuse, switch, connections and all look good but no power at all.
Thanks for any tips!
Tim
Thanks for any tips!
Tim
Last edited by Skitch; 11-25-2003 at 12:18 PM.
11-24-2003, 11:47 AM
#2
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Power comes up on the left side, ground on the right. So, keyed up and defrost switched on, there's no juice with voltmeter back at the hatch? Have you checked or jumped the relay? NOTE!!! If you jump the relay with hatch wires plugged in, use a very big wire! It will cook anything less than 10ga in an instant.
11-24-2003, 12:14 PM
#3
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Right! 10 gauge. One big heater.
I found that the bent copper wire connectors on my old hatch needed to be resoldered to the buss on both sides.
The ground is through the passenger side strut at the ball socket on the pillar. It is not the small wire on the passenger side.
The small wire is to turn on the cargo area light when the hatch is lifted.
So you might want to pop the socket off the ball stud and clean that up for a better ground.
I found that the bent copper wire connectors on my old hatch needed to be resoldered to the buss on both sides.
The ground is through the passenger side strut at the ball socket on the pillar. It is not the small wire on the passenger side.
The small wire is to turn on the cargo area light when the hatch is lifted.
So you might want to pop the socket off the ball stud and clean that up for a better ground.
11-24-2003, 12:15 PM
#4
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Thread Starter
Originally posted by 924RACR
Power comes up on the left side, ground on the right. So, keyed up and defrost switched on, there's no juice with voltmeter back at the hatch? Have you checked or jumped the relay? NOTE!!! If you jump the relay with hatch wires plugged in, use a very big wire! It will cook anything less than 10ga in an instant.
Power comes up on the left side, ground on the right. So, keyed up and defrost switched on, there's no juice with voltmeter back at the hatch? Have you checked or jumped the relay? NOTE!!! If you jump the relay with hatch wires plugged in, use a very big wire! It will cook anything less than 10ga in an instant.
11-24-2003, 12:27 PM
#5
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Ok, what I am checking is from the 8 gauge-ish wire coming out of the pillar on the drivers side to chassis ground. That should have 12v correct? The power goes through the driver side strut throught the heating element and is then grounded by the passenger side strut correct? Just trying to get everything straight, and I found that Autozone has the relay for about $12. I might just try that to test.
Thanks
Thanks
11-24-2003, 12:40 PM
#6
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Right. Power through the large wire coming out of the drivers side, through the DS strut and then the wire jumper on the end to the heating elements.
You should be able to use a volt meter with one side grounded and see the 12 VDC all the way to the soldered on connector on the grid.
You should be able to use a volt meter with one side grounded and see the 12 VDC all the way to the soldered on connector on the grid.
11-24-2003, 03:13 PM
#7
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I just went through this on my 85.5 (actually using SoCal's earlier post). One thing I found was that the little LED in the switch was not coming on, traced that to a blown mirror switch. Then, I was able to get voltage at the driver's side of the hatch but the ground side of the hatch was mssing the soldered lug. Carefully soldered a new one and got it connected. Voila!
I can do with out the wiper but gotta have that steekin defroster.
I can do with out the wiper but gotta have that steekin defroster.
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11-25-2003, 11:17 AM
#13
Nordschleife Master
It should clear up fog pretty quick so you may have too much resistance in the connections and not getting full voltage back there. Measure with a voltmeter and see what you are getting and clean up contacts.
11-25-2003, 11:21 AM
#14
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I noticed when I was first looking into this that the connection from drivers side pillar wire to the strut was barely hanging on. It is probably an 8 gauge wire but only a few strands of copper were still making contact in the crimp connector. That might cause a slow warm up...
