Re: AC programmer ?s

[Pcarselle <pcarselle@worldnet.att.net>]

Steve Brehm wrote:
> 
> Hi guys,
> 
> I've been following this thread since my 87 5KCST is doing the same thing; no center vent air. I'd like to rule out the heater control valve before i dig into the ac controller. i checked all the usual vacuum leak spots and they seem o.k. How do I check out the heater control valve? I tried the golf tee method as Pablo suggests, but i can't get any movement out of the vavle at all. does this mean it's broken?
> 
> Does the Bentley (or anybody on the list) have a good, comprehensive sort of flow chart/diagnostic procedure for climate control problems?
> 
> --Steve
> 
> snip--------
> Yor programmer is suspect....but I would GO! after a vacuum leak before
> anything else....
> In the engine compartment look for Heater Control Valve (rear of engine
> Two Heater type hoses and one vaccum hose attached...disconect vaccuum
> hose...plug with golf tee.....start engine....air from center vents ???
> Yes.... replace small vaccuum hose from plastic tube to heater
> valve....if valve "sucks in" and holds you are ok otherwise suspect
> Heater Valve...
> Test for center vents flow.... Not yet ....keep Golf tee in place....
> At engine compartment....carefully remove passenger side winshield wiper
> arm....
> Remove large plastic cover.... clips close to winshield...and rubber
> grommet all accross engine compartment. Pull evenly and slowly do not
> jerk plastic is brittle...
> Look for "TEE" (no golf) with 3 vaccuum lines... replace the two shorter
> ones....
> Test again....center vent flow....celebrate.... no.....
> Send me anothe message to get deeper into surgery
> Good Luck
> Pablo
Steve:
To check the heater valve you have two methods:
1.- With a vaccuum pump available...disconnect the upper part of a SHORT
Hose connecting a hard plastic tube, to the heater valve. Connect
vaccuum pump to the open end of the hose (other end is at the heater
valve) and pump/check for vaccuum and the diaphragm "sucking in the
actuator of the heater valve and holding ....
2.- Without a vacuum pump... tree shade method...
a) Start car with AC set to Auto and Temp to LO
b) From the engine compartment observe the heater valve actuator, it
should be all the way retracted into the vaccuum servo....if not sure..
note carefully it's position and without stopping engine, set AC
controls to ECON and temp to HI.... check valve again...it should be
completely extended away from actuator...
c) If during test b) the heater valve does not "suck in", without
turning engine off set AC controls back to AUTO temp to LO, disconnect
the hose discussed in step 1 BUT from the HEATER VALVE side...with your
finger check for vaccuum.... if vaccuum is present the heater valve
diaphragm is leaking. If this is the case plug the hose you just opened
with a golf "TEE" and check for center vent air. If  air is there
replace Heater valve.
HTH
Pablo