1983 xj6 vp Help needed again.
Just put new air conditioning compressor and receiver drier but no there is no power on the green/yellow wire that goes to the compressor clutch. The fusible link is ok and with power supplied directly to that terminal it brings the clutch in and the air works.....well sort of. Now the flap that changes the direction of the air refuses to change from demist to face.
Can anyone tell me where the feed to the compressor comes from and where the vacuum to the direction flaps comes from? The flap behind the face vent cannot be easily pushed open.
Col

 

I've moved your question from Australia - Victoria / Tasmania Region to XJ6 & XJ12 Series I, II & III forum. Technical questions are best posted in the MODEL forum and geographically relevant ones (e.g. recommended suppliers) in the REGION forum.

I've also added vehicle details to your forum signature.

Graham

 

the culprit might be the Red Relay mounted above the compressor on the radiator support. Notice the wire at the compressor connector comes from that Relay.

make sure the 5-wire connector under the Red Relay is fully connected to the Red Relay. It is easy to miss one of the slots when pushing the connector up under the relay.

the secondary flap problem is related to vacuum. Sounds like the Servo is acting up. The Servo opens and closes the flaps and it needs vacuum to work, as well as 12v.

 

A light bulb moment, thanks Jose. I removed the air pump and the wire I had connected appeared to go to the intake manifold temperature sensor. The air conditioner was fitted by a mechanic, pipes and gas, and I put the connections on WRONGLY! Tomorrow I’ll look for the feed to the red relay. Starting to make some sense. The vacuum must have some delay on change over for the flaps so I will look at the vacuum.

 

you bet.

hanging by rubber hoses on one side of the battery there is a plastic check valve. One hose goes through the firewall to the Servo. The other hose goes to the engine's vacuum "diverter" valve which is hidden under the intake manifold.

Observe and memorize the orientation of the check valve hanging near the battery. remove it and test it by blowing into it. Air should move thru one side, but not the other. If air does not move from either side, put it in warm water for 15 minutes to unclog it. That might resolve the flaps not opening.

 

I think I get the idea and I also think I know what I have done I’ll look tomorrow. I just removed the vacuum heater tap on my 350sl merc. I hate vacuum when they are staring to get old.
col

 

the Delanair climate system is very simple once you learn about all its complications.

 

Can I use that quote, love it!

 

that's a quote from my mechanic, J.D. at J.D's British Cars in Nashville Tennessee.
He doesn't work on XJ anymore but will show you what to do.

 

Sounds like a wise man!

 

It should be a green/brown wire....but sometimes the color fades.

If you dig deep enough, power for this circuit comes from the mode control switch, through an inline fuse, then through the Ranco thermostat, and then to the thermal limiter fuse at the compressor. I would begin by checking that inline fuse. It's behind the console's RH "cheek panel". You'll see it clipped to the side of the HVAC case on brown and brown/yellow wires.

If no joy it can't hurt to check the other three system fuses while your at it. One in the LH fuse panel, one in the RH fuse panel, one on the amplifier ground wire behind the LH cheek panel. You might end up fiing both problems, as "demist" mode is default when, for whatever reason, the rest of the system isn't working. One clue is the gentle whirring sound of the servo when you turn the temperature selection dial.

The red relay on the radiator support is for the electric cooling fan circuit. It shouldn't have any bearing on the compressor clutch circuit unless someone has modified the wiring...which you'll see from time-to-time.

Cheers
DD

 

"The red relay on the radiator support is for the electric cooling fan circuit. It shouldn't have any bearing on the compressor clutch circuit unlesssomeone has modified the wiring...which you'll see from time-to-time"

exactly, such as if the auxiliary fan has been tied to the compressor with the "auxiliary fan mod", this red relay will stop the compressor clutch from engaging if the red relay burns out.

 

I still can not find the wire that feeds the red relay I have found that the thermal fuse is open circuited but had been bridged out. The green/white wire to that relay coil has been bridged to the compressor clutch. When voltage is applied,via external source the clutch and auxiliary fan operates There are one normally closed and one normally open contacts on that relay.
All fuses inside and outside are ok
Is there somewhere that the relay is fed from that has another open switch such as ambient temperature, if so where is it located?
Col

 

if the wiring harness to the red relay is by itself, and there is no wire tied to one of the two wires at the compressor connector, then you have no auxiliary fan mod and that is ok.

Back in the 1980's and 1990's there was a popular modification done to many of tthese cars to run the auxiliary fan everytime the compressor came ON. Looks like your car does not have it.

So go thru the checks that Doug posted.

 

Two power sources to the red cooling fan relay. Power for the load side comes from the #1 fuse in the headlight fuse box, which is on the left side of the engine bay. Power for the control side comes from the #11 fuse in the LH fuse box inside the cabin.....but voltage from here won't reach the relay unless the temp switch is closed. The temp switch is on the radiator, RH side. You could jump the connectors to test the circuit.

If none of this pans out I'd return the compressor wiring to original configuration and get the system operating normally. You can always go back later and figure out what the previous owner did and/or make changes.

You can get a new thermal fuse from the local auto parts store. The original GM number was 6551258 but they'll have it under a different number.

Cheers
DD

 

Ok I have checked all fuses and none are blown. Have not got s all enough hands to get to the temp. Switch on the radiator any idea where those two wires pop up in the engine bay?
Going to look for thermal limiting switch at a local parts store and I will continue on after that. Has anyone got a diagram of just the “red” relay wiring and how the a/c clutch Is supposed to be wired? I would like to put it back to original if possible.
Alternative is new switch wired to accessories just to bring the red relay in for fan and a/c clutch.
Col

 

Red fan relay

Terminal 87 Green/brown from #1 fuse in the headlight fuse box (12v constant power)
Terminal 87A and 86 Black (ground)
Terminal 86 Light green/white from temp switch
Terminal 30/51 Two green/blue wires. One from the diode and the other to the fan motor

Cheers
DD

 

Compressor

You new thermal limiter fuse should have 3 terminals marked S B C

S - black wire to superheat switch at back of compressor
B - green/brown wire from cabin controls
C - green wire to connector at the compressor clutch

The connector at the clutch has two posts. They are not polarity sensitive. One takes the green wire as mentioned. The other is a ground wire....probably black but I can't remember. If your molded connector is still intact you won't have to think about this anyway

Cheers
DD

 

The new compressor did not have provision for the super heat switch so I will just use two terminals? Unfortunately I can not find anywhere to purchase the thermal overload switch.
Col

 

If you Google "6551258 Fuse" you'll get lots of hits....at least for USA sources. Not sure where you live

But since you don't have the super heat switch the thermal fuse would be pointless anyway. So just run the green/brown wire to one terminal of the compressor connector and a ground wire to the other

Cheers
DD