AC cut-out, secondary fan never starts?

Hi.

At normal highway cruising the engine temp. on my XJ is stable and about 208 deg. F (98 deg. C).
Doing some off-road wheeling yesterday, I discovered that my AC stops working and instead warm air comes out of the vents. When this happened, egine temp. had rised to approx 217 deg. F (103 deg. C) and stayed there while wheeling. When the engine temp. dropped back to normal, the AC resumed normal function.

I suspect that this has something to do with
a) Refrigerant level or
b) Secondary fan never starting.

I've had my XJ for some 9 months, and I have never seen the secondary fan start. When the engine is idling (208F) and the AC compressor is cycling on/off, the secondary fan never starts. Unfortunately, I forgot to check today if the AC compressor still kicks in when the AC cuts at engine temp. above normal (217F).

Before going wheeling today, I checked the secondary fan fuse - continous. I interchanged the starter relay and secondary fan relay in the fuse box - no difference. On my way to and from the off-road field, the AC works fine. While in the field with heated engine, the AC fails again.

XJ: Export (Norwegian) '98 gas 4.0 Ltd./AW4 automatic, built in Toledo, Ohio.

It has everything to do with your auxiliary fan not kicking in. If your at highway speed theres enough air flow to cool your engine AND A/C condenser. At slower (wheeling or city) speeds and your aux. fan doesn't kick in to increase the flow over your condenser your air kicks off. Check your fan by direct wiring it from your battery to see if it's working at all. If not replace the fan and or the curcuitry going to it.

off roading with A/C on? never heard of such a thing......

Wallyman said:

off roading with A/C on? never heard of such a thing......

Click to expand...

I don't really fancy chewing sand... So when wheeling in the sand-pit, I go with windows shut and AC on if it's a sunny day.

It's the secondary fan that's gone. Drive voltage is present at the fan connector by the fan shroud. Voltage is present some split second before the AC clutch engages and it goes away some split second before the AC clutch disengages. I guess everything will be OK when the secondary fan is repaired or replaced.