Heat and AC

[shanezoid]

I have a 97 ranger with a4.0 and a manual transmission. When I am driving and my motor starts to strain like going up a hell the heat or whatever I am running will switch to the defrost and when the motor comes out of the strain it will return to norma. Any Ideas. Thanks Shanezoid

 

[Earl43P]

Vaccum leak. Check the line that goes to the HVAC accumulator (black plastic sphere) for holes, cracks, burns. The fitting it connects to is a checkvalve, it could be bad (HELP section has replacement checkvalves). Could be the heater flow valve line too, so check it, valve is located on one of the heater hoses. Really could be any vaccum line so inspect them all. Very common problem with Fords.

If you can't find the accumulator, it may be hidden under the WS/Rad tanks bolted on the right fenderwell liner, forward. I think it's easier to remove the wheelwell liner to get to it.

 

[shanezoid]

I will swap aout the accumulator and let you know what happens. Thanks Shanezoid.

 

[Earl43P]

I'd do a lot of inspecting before I changed any parts.

 

[MAKG]

I'd do a lot of inspecting before I changed any parts.

I agree wholeheartedly. It's relatively easy to check vacuum parts for leaks.

Like, when disconnecting the vacuum reservoir line (some folks DO call it an "accumulator," but there is another part by that name in the A/C system) from the intake manifold and capping the nipple, does the problem go away?

 

[shanezoid]

I took off the accumulator and cut it in half. There is a check valve inside that had came loose, I reinstalled it and wire tied it in place. Then I took some pig putty and put the two halves back together, painted it and reinstalled and as best I can tell the problem is gone. The check valve you can suck through it but you cannot blow through it so I feel condident that was the problem. Thanks Shanezoid.