'98 Malibu rear window defroster not working

Reply

  #1  
Old 08-26-10, 06:55 AM
G
Member
Thread Starter
Join Date: Nov 2006
Location: US
Posts: 375
Received 0 Votes on 0 Posts
'98 Malibu rear window defroster not working

Last fall I discovered the one contact lead to the rear window defroster grid (wire) had come off the little metal pad on the one side - hence no rear window defrost... So, I bought one of those rear defrost patch/glue kits at the auto store, followed the directions meticulously for cleaning the contact plates on the terminal-wire and on the windshield pad - applied the electrical conducting glue in the kit and held it there for 5 or 10 minutes while it setup.
The next time I used the rear defrost it seemed to work fine but the second time it didn't. While checking the connections on each of the terminal wire-to-pad conntors, I thought I noticed a little place where the fog had cleared around the repaired contact connection but after that no sign of any heat whatsover.
I thought it might be a fuse but cannot find anything in the owners manual designating a fuse for the rear window defroster in any of the 3 fuse boxes this car has. Googling the problem, I found a reference to some kind of electrical box component, mounted either behind the fold-down rear sear or in one of the body columns behind the plastic molding - I don't recall ever seeing anything behind the rear seats when I drop them in the down position.
Anyone know either where the fuse is for this or where that electrical component for the defroster is located?
Thanks,
greynold99
 
Sponsored Links
  #2  
Old 08-26-10, 09:19 AM
B
Member
Join Date: Oct 2008
Posts: 1,312
Received 0 Votes on 0 Posts
With the rear window defrost on, measure the voltage at the two wires for 12 volts. That would indicate the fuses and wiring are working.

I would suspect the metal tab connection. If you are getting voltage at the wires, then I would suggest taking it to an auto glass business and they should be able to fix it for not too much.

If you are not getting 12 volts, I don't know about your specific vehicle, but there are probably two separate fuses and a relay and or computer module for this. If you are not familiar with troubleshooting electrical wiring and don't have the factory electrical diagrams, then you are best to take it to a dealer for repair.
 
  #3  
Old 08-26-10, 06:40 PM
ukrbyk's Avatar
Member
Join Date: Mar 2010
Location: USA/ Pacific NW
Posts: 3,549
Received 5 Votes on 5 Posts
ahm, and the defroster button in the climate control unit might be faulty either. it all goes down to, like bill said, having 12 V at terminals. i have never seen a car that did not have a fuse for defroster.

i used that repair kit once, on 04 honda, as tint guys cut one of the grid wires. it worked very well and very easy. but truly it goes down to how well the surface was prepared for the conductor application. check the voltage 1st, take it from there. prolly that fix did not catch.
 
  #4  
Old 08-27-10, 10:53 AM
I
Member
Join Date: Aug 2010
Location: United States
Posts: 10
Received 0 Votes on 0 Posts
These vehicles have a common problem of a electrical module over heating and melting that goes to rear defroster. This module is only about a foot or less upstream from the actual connectors that you slide onto the metal tabs on the glass. It is either going to be tucked into the headliner at the rear glass on the passenger side rear corner, or behind the plastic trim panel that si on the pillar that runs along the edge of the read window on the passenger side (runs from roof to carpeting on rear deck). This panel generally pulls off with no tools, and if I remember correctly this module (looks like small black plastic box) usually fails in cars with the radio attenna built into the rear glass.
 
  #5  
Old 08-30-10, 08:21 AM
G
Member
Thread Starter
Join Date: Nov 2006
Location: US
Posts: 375
Received 0 Votes on 0 Posts
Reply thanks and question for Inspector808

Thanks to all who've responded...
And I must admit obligations over the weekend didn't even permit me time to test the 12VDC at the defroster terminal. However, I did find the fuse Number & Location - it's #33 on the main engine fuse compartment.
Hope to test tonight... But I did have a follow up for Inspector808. It sounds like this would also appear as a No Voltage reading on your voltmeter?
I ran across a post on another forum about this - seemed to indicate that the module hadn't failed but that the connector failed where the wire from the defroster comes to the module. The person fixed it by soldering the wires directly to the unit - don't recall if he had to disassemble the 'box' to do the soldering. Do you know what is required for this repair (Once I find it...)? Is the failed connection 'inside' the unit or will I be able to see it?
Thanks,
greynold99
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: