Whats this wire?........& this hose?

[Waste_Gate]

I found this wire hangin out by itself near the receiver/drier. The A/C hasn't worked since I've owned the car but thats about to change in the next week or two. The aux fan has only come on once in over a year and that was due to prolonged idling after city driving so the coolant temp circuit activated it (gauge was reading about 100C).



This is where the line circled in green from the pressure switch joins the compressor wire.



And finally, I noticed this tube was cracked where it joined the plastic fittings. I duct taped one side and wasn't sure what the purpose of it was.
I was kinda thinking it was for recirculated air but I'm not sure.



And this is Dmorrison's picture for a reference on the hose (from his definitive evaporator replacement DIY).



Thanks for any insight.

[vstech]

welcome to the forum! (another kakalacky resident! (I'm in N. kakalacky))

[Waste_Gate]

Originally Posted by vstech

welcome to the forum! (another kakalacky resident! (I'm in N. kakalacky))

I hear you Vstech, I love north carolina, we go up to lake Lure every now and then. Have you ever been to the Geneva?

And about the wire:
Could it be that there was originally just a one spade switch on the receiver and that got replaced with a two spade switch for pressure & temp?

The compressor is shot and I'm waiting to get the upper hose rebuilt before i install it. Also, the push button unit was replaced in 2006 with a programa unit and i recently opened up the boards and resoldered a burnt strip to cure my spastic clicking.

[Phillytwotank]

That hose in someone's left hand is part of the air temperature sensors system. That elbow should just be connecting the to visible ends there.

Welcome! See you rolling around Columbia.

[ROLLGUY]

Sounds like you need to "Sandenize" your 'Benz.....Rich

[Waste_Gate]

After looking at a wiring diagram of the a/c system, it looks like someone previously bypassed the Klima relay.

#27 is the pressure switch. The disconnected blue wire at my drier obviously goes from #27 to pin 10 on the Klima relay (c & d is the wire pair connected on the other spade of the pressure sensor). Lastly, the yellow circled wire by the little red junction is from the Klima relay to the compressor. I don't know why this would have been bypassed but I do know the PBU has beer replaced with a Programa unit about 6 yrs ago.

I hope this helps somebody in the future.



Edit: I just re-read a post from Dr Bert & Brian Carlton and infact the Klima takes the signal from the Tach to cut the power to compressor but if tach isn't working, the compressor clutch won't engage. My tach has been dead for a while judging by the un-even discoloration on the needle. This could be why someone previously by-passed the Klima.

[vstech]

what year is the vehicle in question? there was no klima prior to 85 I think...

[Waste_Gate]

Originally Posted by vstech

what year is the vehicle in question? there was no klima prior to 85 I think...

I think I need instructions for putting that info in my signature.

She's an 85, and there's her Klima

[BillGrissom]

Beautiful car. The "cracked hose" looks like the drain snout for the under-dash climate box. it has a flexible lip that is supposed to open to let water out, but close to keep engine fumes from flowing back. My 82 Dodge Aries had a very similar looking drain (same supplier?). I was getting water on the floor and found the "lips" stuck together. When I popped them open, a bunch of water flowed out. Not a problem in my 300D's because that drain is cracked just like yours. I don't smell engine fumes, so no concern.

If the wiring diagrams didn't explain it, ask and I'll take the time to post photos of my pressure switch, but could be different since CA models had a different air filter over that (since removed).

[Waste_Gate]

Originally Posted by toomany MBZ

What car?

I can't open the pics either.

Sorry about that I didnt know if my car showed up in my sig. Its a 1985 300CD

I'm about to get the pics up again.

[vstech]

Originally Posted by Waste_Gate

Sorry about that I didnt know if my car showed up in my sig. Its a 1985 300CD

I'm about to get the pics up again.

I fixed the original post, and removed the questions about the pics.

it looks like someone bypassed your a/c wiring... likely due to a bad push button unit. or freeze switch under the dash. either way, fixing it means rebuilding wire...