2004 Blazer Xtreme Trailer wiring

[dsevern]

Actually, from the research I did on the net, this question applies to just about any new Chevy truck with a factory "heavy duty" trailer wiring harness.

My 04 Xtreme Blazer came with a factory hitch and wiring harness, but no plug on the end. The wiring harness is an "8 wire heavy duty harness" according to the manual (and it is, I checked).

Now, why they put a heavy duty hitch and harness on this vehicle is beyond me, but I figured if I'm going to wire it up, I want to do it right. In reality I only need the 4-pin flat connector. So I head to the auto parts store and the most I can find is a 7-pin connector. I checked three different places, checked all over the net and called the dealer. The parts guy at the dealer told me he's only ever seen a 7-pin connector. However, a quick search on the net shows that almost (if not all) new Chevy trucks that come with a towing package come with and 8-wire wiring harness.

So, my question is, where the h*ll do you find an 8-wire connector. What did Chevy intend to be put on the end of this thing? I know I can just use a 7-wire and not use one of the wires from the harness, but again, I'm thinking Chevy intended for it to be 8-wires, there must be a connector to match it.

Anyone?

Thanks in advance.
Dave
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[Mikado14]

Don't know why there are 8 wires but if you look in your manual, there should be a description of what all eight are. 7 round is common and is usually a metal plug and socket. There are 6 and 7 flat (referred to as RV connectors) that are plastic. Out of the seven wires you should have:
1. Left flasher
2. Right flasher
3. Running or tail lights
4. Ground
5. Electric brake
6. 12 volt for accessory or charging breakaway battery
7. Gound

These are not the pin configuration just what wires should be there. There is a possiblity that the eighth wire is for a seperate stop lamp.

[dsevern]

Right, I already knew that the description of what each wire is, was in the manual.

Again, my basic question is, what kind of connector did GM intend to go on the end of this harness? And where can one obtain it?

For now, I've got a 4pin flat/7pin round adapter on the end of it. Of course, I realize I'll never be towing an RV with my Xtreme, but as I said, I wanted to wire it up properly regardless of what it's going to be used for.

Also, any recommendations on towing with my Xtreme? SHould I add a transmission cooler? I'm only towing a small 5'8' utility trailer with band gear loaded in it. Not a lot of weight per se, but then again the Xtreme is only listed as having a 2000lb towing capacity anyway.

Thanks in advance!

[BlazerLT]

The Xtreme should not be used for towing.

It doesn't have the suspension or the proper gearing for it.

Also, I don't think it has a tranny cooler.