After spending the afternoon trying to clean up the mess some previous Dr. Frankenstein made of the wiring in my Jimmy I found some harness that went to nothing and I don't really know where to start looking as far as wiring diagrams go to figure out what they are since I have no idea what the are. I'm hoping you guys can help me identify what some of these go to.

This first one I believe has something to do with the choke. If it grounds out it blows the choke fuse. But that's all I know.



This second one I'm pretty sure is part of the missing cruise control but would like some one to verify.



No clue what this is. It T's off a wire going to the A/C compressor about a foot before the compressor harness.



No idea what these go to either. They are on the passenger side between the engine and blower.



Here's another I don't have a clue about. It's under the dash on the passenger side.



I would really like to know what this is. The white tip is a button or whatever. The wiring was disconnected when I found it so I hooked it up to see if any fuses blew or anything operated differently but so far I have notice any differences.




Any answers would be great. Shoot any suggestions or ideas as to what it might be would be awesome at least then I would have place to start looking.

 

also post what year blazer it is. if its a newer one like a 1990 and has a 75 engine in it you are going to have alot of crap disconnected also if you have a repair manual you can look through the wiring diagrams and match up the colors in the pictures.

 

Thanks for the quick response. What does the brake light switch do? My break lights worked without this being hooked up so I'm assuming it does something else?

Good point. I forgot to add that piece of information. It is an '85 Sierra Classic with a 350. I do have a repair manual but it doesn't have the most detailed wiring diagram. Not to mention after the excessive wiring crap I have gotten rid of that I KNOW were added on and/or attempts at rewiring stuff I'm not sure if these are add-ons or factory wiring harnesses.

 

ha. thats not the brake light switch. wtf is it then.... i wonder if its for the cruise control then. might be to release it when you hit the brakes. i vaguely remember messing with one on a old chevy station wagon like 8 years ago. brake light switch looks just like it.

i have a 86 chevy myself but it was a diesel and now has a 73 gasser in it and different wiring harnesses so its a mess too. sorry i cant be much more help. kinda falls under that category if everything works leave it alone

edit... yeah looking at that brake light switch again i didnt see the vacuum hose going to it. thats gotta be for the cruise control. i barely ever messed with that stuff other then taking it off and throwing it in the garbage which is what it looks like the previous owner did too lol


heres a link with that switch

http://www.jcwhitney.com/ac-delco-oe.../p3041833.jcwx

 

It is indeed the cruise control.

 

After reading your post I had come to the same conclusion but I wasn't able to find the exact same switch but looking through my manual I found something resembling it. Thanks for the link. I guess now I need to get to work on getting the missing parts of my cruise control to get it back in working order.

Do you know exactly what that switch does? It's not mounted to anything, it's just laying loose under my dash. Is that how it's supposed to be?

Now that I have some of these harnesses figured out does anyone care to take a swing at the remaining few?

 

Your truck likely came with the electronic distributor as well as the E4ME carb that had all kinds of electrical do-dads on it that you no longer have nor do you want to have ever again.

 

Do you know exactly what that switch does? It's not mounted to anything, it's just laying loose under my dash. Is that how it's supposed to be?

Disregard, I finally found the page in the manual I have that talks about it.

 

it mounts somewhere by your brake pedal. so when you brake it disables cruise control like a modern day car. everything was all goofy with vacuum back in the day

 

That green connector in the fourth picture is for the Electronic Spark Control Module, I know that for a fact.