Fair or foul?

[azpima67]

On recent trip up north the fan stopped working (outside air & AC) when loading the engine such as going uphill. Typical vacuum problem, in my experience. At my son's town (Brigham City, UT) I had the local Ford dealer (but one of the multi brand mega dealers) fix it. They replaced a vacuum line due to a small crack. That fixed it but they took it for a test drive and said "concern was still present".. Recommended that the "climate control solenoid and manifold assembly is leaking" per a smoke test. Part not in stock and wait was 3 days (and some $400 cost). Declined since I could live with the problem ( AC/outside air blower works when no load on engine) and my schedule didn't permit the delay (had 2 HS grand kids graduations to attend).

The next day went to WY over steep mountain grades without any problems -- blower never cut out. Same on the rest of the rip up to S. Idaho and back to Tucson and around Tucson in 100+ degree temps..

While working on the Exp they checked the brakes, tires and battery which were all OK. So I am wondering if the recommended solenoid/manifold really needs replacing?

 

[94Eddie]

Sounds like you might have a bad AC control valve. It allows the vacuum reservoir to hold a vacuum when the engine isn't producing a vacuum like when it is under load. This causes the HVAC controls to send the air to the defrost vents. Then when vacuum returns it goes back to the current setting. Is there a slight hissing noise coming from the vacuum reservoir from the glove box area when this happens?

Mine went bad and replacing the valve fixed it. A link to the part is below. The valve is in the engine bay on the passenger side of the engine near the firewall. It is easy to spot. It is a one way valve so make sure to install it in the same configuration you found the old one.

Amazon product ASIN B000NU8FFY

 

[azpima67]

No hissing. On a long uphill climb out of the SL valley to WY, didn't have any trouble with the fan stopping (or anytime thereafter). Just wondering if the solenoid/manifold really needs replacing.

 

[Bazz270]

prior to manifold replace check your intake vacuum value first (using forscan vacuum PID measurement).intake vacuum leak will cause brake booster malfunction and emission control DTC also.

did you check vacuum line near firewall grommet ?

do you have any Climate control related DTC?

what about A/C blower grounds or power blower wire to SJB module.