Hey there,

Just got inside from poking around with the '92 for a bit. The center face vent vacuum solenoid finally gave up the ghost, and the R/H side defroster flap isn't sealing 100%, maybe diverting about 85% of the airflow that it should be when the A/C is on.

I blocked open the center vents, and I'm okay with 85% on the defroster flaps. Some day I will take the fascia out and go from there.

I was going through the Delanair Mk. IV manual for these cars and noticed the Heater Water Valve was deleted at some point before my '92 was manufactured. The solenoid and wiring is there, but it's blocked off.

The A/C on most of these R-134a converted cars is pretty marginal, and age isn't helping the problem. I'm trying to see what other easy things I can do to improve the A/C performance. (I should note that I have a brand new condenser ready to be installed, and just need a new compressor, expansion valve, and receiver/dryer to do a full system overhaul -- my compressor clutch is getting noisy and will need to be replaced at some point, so I'll do it all).

Now to my question: Does anyone know why these valves were removed? Was it felt that it was unnecessary, or caused problems? Weren't they reinstated for 93 or 94 MY cars?

For ~$10, I can get a brand new heater valve (this year would've had the inline valve, not the one that goes into the head, and I even have the short stubby hose, which I accidentally ordered when I replaced all the coolant hoses. So I would only need to route a new vacuum pipe or hose.

Any ideas?

Thanks,
Nick

 

There were no heater control valves for 3 years (1990-1992). Many cars don't have the valves, they just have the heater matrix blocked off in a box and shut off air flow.

You can run a red plastic hose from the vacuum actuator to the new valve.
It does not have to be red but that is the color designation for heater valve.

Sometimes you can reach into the demister grille and grab the control flap. Pull up and replace the fastener screw. The GREEN plastic hose is for the demister.

Black hose for center vent.
Blue hose for cabin fresh air/ recirc.

bob

 

Hi Nick,

On our '93 the problem with the demister flaps was that the plastic hinge pin had snapped off at the end where the solenoid is mounted. I was able to repair them by drilling a small hole into the flap where the pin had been and installing a small sheet metal screw to replace the broken pin.

Worst case, it's really not difficult to remove the dash. I didn't take step-by-step photos but the instructions are in the workshop manual:

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And in case the blend flaps may be part of your problem, here is more than you ever wanted to know about them:

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Welcome to Jag-lovers - Members Photo Viewing Page
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Cheers,

Don