I did my first oil change today on my '97 Ram 2500 that I recently bought. When I was underneath the truck I noticed what appeared to be a pink/red vacuum line that was cut in two. It was right by the tranny. Anyone know what it is for? The truck seems to shift and run fine, though.




Also, when under the hood a few weeks ago, I noticed this unplugged. It looks like a sensor for the AC or something. Can anyone tell me what it is
and what it does? Thanks, just wanting to know if these are any important things.

 

Is it 4wd? second photo looks like refrigerant switch, and cotter pin looks like it is jumping the cricuit....which means something is wrong and someone was hiding the problem.

 

The vacuum line looks like the one running to the CAD. Not sure about the plug.

 

Red line is for you cad. Need to splice that back together if you want your front axle to engage. (or, disengage, as the case may be....)

Plug goes to the low pressure switch on the receiver/dryer. My guess is, your A/C doesn't work? I would plug it back in, and then test the A/C in the driveway..... It is probably unhooked due to a problem with the compressor.

 

Yes, it's a 4WD. Does it possibly have something to do with that? Also, I had the same idea of the refrigerant canister or something for the second pic. The guy I bought it from said the AC worked, but I could not test it since when I bought the truck it was still cold outside, so trying to turn it on and see if it blew cold air would have been useless.

 

Whattya mean? It woulda worked GREAT. Ice cold air.

 

Thanks for the answers. Funny thing is, 4WD works and engages as I tested it before I bought it.

So I guess I'll need to remove the cotter pin and try plugging it in and see if the AC works. It is getting warmer now, so I should be able to tell if it really is blowing cold air now.

 

I didn't see the cotter pin...... that bypasses the low pressure switch, so, the compressor may not run with it plugged in to the switch. Either a bad switch, or, low on refrigerant. (and that really wouldn't be much of a surprise, given our trucks penchant for wanting folks to pull the dash to change various thing.....)

 

That's the first thing I noticed.....Seen that trick before!

 

I bet 4x4 doesn't work now. That line may have broke after you bought it.

As far as the cotter goes, remove it now! Damage is being done to the ac system(too late now anyway I'm sure) and it's dangerous. Put the plug back in the switch. If the ac doesn't work, you need to fix it.