oldblues

hi
is there a heavy duty fan clutch for the diesel ?

prob is when sitting in trafffic a/c goes warm ?

start moving even at 20 mph and a/c cools agin !

dozer12216

Is engine overheating? Weak fan clutch would allow engine temp to build.
Inspect radiator for obstructions to air flow. Bugs, oil from puke bottle(24V), and debis between rad/ charge cooler/ ac condenser/atf oil cooler can cause condition. You should be able to hear rad fan clutch come on as temp hits about 210. Can readilly feel air flow increase also.
Low ac charge or HVAC door malfunction also possible.

Busboy

Like dozer says check for the radiator being dirty this would restrict airflow through everything, the freon charge may be down a little also. I agree with you about poor design and not using a separate electric fan just for the AC condenser like a lot of the smaller cars do.

oldblues

hi
rad is clean i had it out and washed and blew out dirt .

no engine does not over heat which may be the problem of it running too cool and the fan clutch not engauging while sitting in traffic ?

i have heard it ingauge at times so i know what it sounds like .

just wondered if there may be a fan clutch that would engauge at a lower temp . there is one for a gas truck but it has a right hand thread nut so will not install on the 12 v diesel ???

is there a thin elect fan that can be mounted to the 2nd gens to correct this prob ??

system is full , just not enough air flow sitting in traffic !

bent valves

I read somewhere that if your thermostat is stuck open your fan clutch may not heat up enough to engage the blade. This should be obvious if your temperature gauge is staying at a low temperature. I replaced mine a few years ago with one from NAPA, (Part # 272313) It was made in USA and less than $70.

To test the fan clutch the shop manual says: If the fan assembly free-wheels without drag (the fan blade will revolve more than 5 turns when spun by hand), replace the viscous fan clutch. This spin test must be performed when the engine is cool.
Good luck.

kd460

My money is on problems with the ac. The freon charge is probably low. Why is it low? Thats the million dollar question. I would beg, borrow, or steal a set of ac gauges and see whats up with the system.

At least would be to get a can of freon and one of the cheaper 10.00 gauges just to see what you ac system is doing. KD