What does this connect to??

[87k5]

Hello SS folks, I like many other new people to this forum wait in the wings a while to post up things to learn the etiquette of posting as to not over post the same topic over and over again. So with that said here is my story:

I bought my M1008 (truck) before I deployed to Iraq last year. Mine came pretty complete minus the alts, pass glass, and glow plug card. I purchased my alts, w/ iso grounds from a friend, installed and could not get the wait light. I did some more research and found I needed the glow plug card as well for the truck to activate the glow plug relay. I made the push button bypass people seem to rave about and it works like a charm. I changed the oil, trans fluid, fuel filter, and checked the diffs, t-case, power steering, and radiator, with all of this done I cranked her up (I don't know how long it sat prior to me purchasing it.) It took a few times of glow plugging and cranking, so much I had to remove my batts and take them to the auto parts store to let them charge them over night, but she eventiually started. Purs like a brand new truck, smokes a little on startup but that is it. I pulled out of the driveway and headed down the road to find she had a horrible vibration, rear drive shaft, yea my truck fell victim to a forklift at some time before I bought it. A local shop fixed me up with a new one so no big deal. SO with all of that said here is my question:

1. I was working on my non-working headlights and trobleshot it to a small connector under the steering collum I am not sure exactlly what it connects to, or what connects to it please help. I have attached pics.

2. After my truck has run for a while I will get a mixture of anifreeze, and air bubbling up through the overflow bottle not enough to make it over flow but enough to fill it up. My suspussion is a bad/ old radiator cap, or is the thermostat sticking closed?

Thank You for your help

 

[maybefixit]

Regarding the radiator cap: I've found that when in doubt, replace. I was lucky enough to find a radiator pressure test kit at an auction many years ago, and it's nice to have. I think every radiator cap I've tested that was over 10 years old was holding less than half its rated pressure. Often the gaskets will be visibly cracked on the underside of the cap, same kind of weatherchecking as old drive belts and tires. The rubber hardens up over time.
Since the caps are usually under $10 it's almost not worth the trouble to test much. Some really old caps won't hold more than 2 psi, they bleed off immediately. I don't know if the orange box stores will rent / loan out a test kit.

As a side benefit, I found out that the new radiator cap makes the engine warm up a whole lot faster in the winter. Not sure why; but I've seen it happen multiple times.

 

[319]

Looks like the connector is for the dimmer switch, which should be mounted on the steering column by the ignition switch (not lock). Check (illustration E14) on page E16 of TM 9-2320-289-34.
I'd replace the radiator cap also.

 

[ida34]

The bubbles scare me. That sounds like a bad head gasket. Even if the cap is bad that will only control when the coolant exits to the over flow. If the overflow is filling up then something is forcing the coolant out. The overflow is only there to account for the thermal expansion of the coolant. Pull the cap off when it is cold and start the thing. If you still have bubbles coming up from the radiator then you probably have a head gasket leak. This all assumes it is not overheating. If it is overheating then the coolant boils and the steam will push out and bubble. The radiator cap is supposed to hold a certain pressure as higher pressure raises boiling point. A bad cap will allow the coolant to boil at a lower temp and this may be causing the overheating may be causing the bubbling.

 

[rosco]

It seems like for every pound of pressure, it increases the boiling point 3 degrees F. On the important issue: bubbles - they can, in a worst case situation, be caused by a cracked block. You might try something like "Bars Leak", and hope for the best.

Lee in Alaska

 

[87k5]

Thanks for all of the input, I did find a leak in one of the hoses coming from the heater core, fixing that made most of the bubbles go away. I found the plug that has nothing connected to to to be a low/ high beam switch. Ordered it at advanced today. I would like to get a picture of someone's switch if they have one, just to see if the one I got is going to be the right one and to see where it mounts up to. I know it should be pretty much self explanaitory but you know how that goes. Thanks for the help again.

 

[319]

The dimmer switch attaches to the column at the same point as the igniton switch. If you're missing the dimmer switch, you're probably missing the rod also.