Hey guys, thought I would share my experience with everybody as I have read this issue online a few times but never found anyone with a solution. The symptoms I was having was that the rear defroster didn't work and the radio would come on and off at times and would shut off if you turned on the rear defroster. These issues had been circumvented by a previous owner (who didnt know **** about electronics) which caused another Issue. But Ill start from the Begging

It started with no coolant....
When I bought the car almost as soon as I drove it Away I got a low coolant light. I discovered this forum and read about the Infamous "leaking coolant elbows" I ordered a set of aluminum ones from ZZP and awaited their arrival.
When the elbows arrived I set to removing the old ones, boy was I in for a surprise.
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When I did this I noticed that the wiring harness was soaked but put this information in the back of my mind.

Later I blew my cigarette lighterr fuse so I went to change it and found this!
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Needless to say this concerned me, but as time went on I never got around to investigating it.

Then one day many months later driving home from a friends I noticed a strange burning smell whenever I turned on the Rear defroster. I investiaget further to find this!
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I immediately contacted Jason and found a suitable replacement for the fuse block from an impalla (assuming that the fuse block was my problem)

I pulled the old one and began to take it apart looking for the failed components
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I noticed a continouity between the rear defogger and the Radio circuits so I went to look for the wiring diagrams. But according the the diagrams



Rear deffoger and radio run off of different power sources. So I assumed this was the fault. But After testing all the voltges and leads it just didnt make sense. I knew that the two circuits had to be connected. So I did a little forum searching and found an thread from the old days of MCF (back in 2008 i believe) that someone said they had re re-routed the deffoger power from their junction box and lost Radio power. I was also noticing a drop from 13.4V too .34V when there was a load on the circuit. That told me there was a significant draw in series with the radio circuit. I began chasing wires back untill I ran into the old plug on the wiring harness that had been soaked when i changed my elbows. The plug had also been hanging loosely for sometime and had rubbed against the accessory crank pulley more than once. I cracked it open to find this


I knew instantly this was my problem. I started to work on it after looking for another plug at the junk yard (apparently it is unique to Monte Carlos). being unsuccessful in locating one I went to fix it best I could. I pulled out the plugs and this Is what I found.
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the seals on those two wires were completely toast. The female plug on the right is actually so baddly fused into the hole I ended up cutting the wire and re routing that wire outside of the Box. I moved the center wire over to the socket on the left side (after cleaning the carbon off the contacts of course.)

no we're here!
20140110_195950_zpsc30fefe2.jpeg Everithing cleaned and all neccessary splicing sealed with high heat silicon and electric tape. (also fixed a poor splice done by a previous owner)

And that is the longest running problem that I had in my monte!

 

Holy crap!!! I know you mentioned some of this, but seeing the additional pics brings it home. Great detective work and sharing your information!!
I've seen the '06+ Montes and Impalas have a problem with the defroster wire in a connector (much like you showed), but I never heard of it in the earlier generation!
Thanks again, I'll make a mental note to think about that in the future!

 

I think its probably a pretty rare problem but all the things that cause it to happen were pretty common issues. Thanks again for all your help too. I know I'v read allot of people having that radio goes in and out issue and even looking at a wiring diagram you wouldnt know to look at the rear defroster.

 

Wow impressive detective work. I believe you found the preverbial needle in the haystack when you diagnosed that issue.

 

As mentioned previously...
Great Job of finding whats what...
I'm shocked at that someone did use all those jumpers as a part time fix...
I know that wouldn't happen at a dealership....I Think?

Either way..it definitely wasn't the right solution to the problem and its to bad someone didn't give you a heads up before you bought it...

anyway thanks for the detailed fix/info!

Great Job!

 

And to think David, a couple of months ago you were Worried about installing a Stereo? You have more Electronics and troubleshooting knowledge than you believe. And finding this problem is just one example of how you CAN use that knowledge Off the Airfield. Good work!

 

thanks JC
Stereo was just an animal I had never seen or played with before. Now im pretty confident I could install a similiar system in alot of cars.

 

You are the man! Notice any differences on how she runs. Any dimming or power surging issues before?

 

It was all interior power, The power seats move faster and the radio works all the time now. The radio and rear deffoger had issues. thats the only place it would have caused issues.