Im getting intermittent heat in my 1979 E150 Van.

I was sure the blower was starting to go, but went to a garage and he told me he flushed the core, that everything looked good, tested the blower, blower ok. He says that its probably the aftermarket thermostat i put in.

He recommends i get a stock ford thermostat and that should fix it.

Does that make sense? if the thermostat was wrong, wouldn't it just affect the temp of the air blowing out? The volume of air blowing shouldn't change?

The air blowing never gets cool, it just stops blowing as hard.

Im confused but i THINK it makes sense.

 

My '84 does it too. It will blow hot and somewhat hard and then just cuts off completely and the heat just seeps out.

 

exactly! any ideas? if its blowing hard then barely, that WOULD be the blower right?
The heat is always there, but if the strength of the blowing air is alternating, what else could it be?
we tour with our van in canada and its getting pretty unbearable.
Gonna put cardboard in front of grille to slow down cold air rushing in, but consistent heat would be nice.

 

Same problemwith mine. Turned out the fan swith on the dash was failing. It would heat up and loose contact. Cool down and restart. Sometimes it would restart by wiggling the switch.

 

you replaced the switch then?
how hard to find and do?

did you manage yourself? what you're describe makes sense, cause a mechanic told me that he tested the blower and was not problem.

 

Sweet, i just found that switch you're talking about: HVAC Blower Control Switch.
About 8$, gonna try that first since its such a cheap part.

will let yall know

 

I'm a Quad so all my mechanical has to be done by someone else. I use my neighbor, a retired Ford dealership mechanic/shop manager. He does all my repairs both vehicular and farm equipment. Took him about 15 min.

With two diesel E-350s, two diesel F-250s, a Jeep, two Nissan pickups, a motorhome, 2 ATVs,an Excavator, 3 full size tractors, hay baler and other misc. equipment I see him more than his wife does. And my wallet shows it!!

 

Man, you struck gold with that neighbor!!!!!!!
Any houses for sale around you?
hahahahaha

think im gona get that part today, see if i can do it.

Cheers

 

Which one of these be the fix?

Electric Fan Thermostat
http://www.autozone.com/selectedZip,.../selectZip.htm

Blower Control Switch
http://www.autozone.com/N,15201030/s...eResultSet.htm

 

Mine was the HVAC (Blower Control Switch.) The heavy amp draw from running the AC on max most of the time the van was driven caused the switch to heat up and eventually fail. Had the problem on two van 1988 E-150 and 1992 E-350 suspect my 06 E-350 is beginning to fail. The 92 E-350 failed within two weeks of dealer delivery.

 

Fellow members...with or without air conditioning makes a big difference.

It may have to do with what's attached behind the dash to the A/C heater control panel.

The Ford nomenclatured: Air Conditioning Vacuum Selector Temperature Control Valve Assy. (whew!). Ford basic p/n: 19B888.

This is a multiported plastic vacuum/electric valve that has 8 (more or less, it depends) connectors where plastic vacuum tubes attach and go various places.

At least 3 of those tubes go to the blend door motors.

Slide the dash control lever, the vacuum valve closes one blend door and opens another. The blend door motors themselves might also be defective.

The blend doors include the defroster door, the a/c door and the heater door.

Also on that mouthful of a valve is the electric "kicker" switch that turns the A/C compressor on, when the selector lever is slide to A/C.


One more thing = with A/C you get that marvelous piece of Ford engineering...the dreaded inline vacuum controlled heater water valve.

This POS has been used on Ford trucks and cars since the early 1970's. It's plastic and includes the vacuum motor.

It has a nipple on top where the plastic tube from that mouthful of a valve (19B888) goes to. The plastic hose may have been spliced with rubber vacuum hose by now, because those plastic tubes crack open.

It fails on a regular basis...if one lasts more than a few years, it's a miracle.

When it quits working you get one of three things:

No heat, some heat, or heat all the time, because when it goes south, you can't turn it off!

It splices into the heater hose, either at the center rear of the engine compartment, or on the passenger side.

D4AZ-18495-A (Motorcraft YG-136)

Still available from Ford, and why not..it's been on Ford's best seller list since the 1970's.

PAH-LEEZE when asking questions, list what your vehicle is, w/ or w/o A/C and the model and engine size.

Outside of that POS heater water valve, it's tough enough figuring out all this stuff, without flying blind.

 

Sorry for the lack of info.
My 1979 e150 doesn't have AC, i found the HVAC blower switch at my local ford dealership, gona swap that out and see later today.