heater fan

Guest · #1 (**permalink**) 07-20-2003, 07:00 PM

I have a '98 cherokee larado. When ever you have the heater/AC fan on when it's cold or hot it comes and goes. When traveling at normal speeds the fan works fine but if you slow down and start to accelerate the fan dies until you reach cruising speed again. In fact the fan dies everytime you accelerate whether to pass or starting out from a dead stop. One last thing the AC cools fine we just had it converted to 134 but the compressor at idle sounds awful any help or does it mean new compressor

TerryMason · #2 (**permalink**) 07-20-2003, 07:00 PM

I would say that the fan coming on and off would be an electrical problem. The wires probably move / loose contact when you take off, and when you level out, they make contact again.

As for having to replace the compressor, I don't know.

Terry

kbest · #3 (**permalink**) 07-20-2003, 07:00 PM

Terry after paying closer attention to the blower I'v figured out that the fan doesn't quit blowing but goes from vent to defrost. It appears to be something wrong with the vacum lines. I'm not for sure but doesn't the select (vent, heat, ac) mechanism work off of vacum.

DeeRichJeepz · #4 (**permalink**) 07-20-2003, 07:00 PM

I'm not so sure its a loose wire. We just bought our 98, and we are having the same trouble with our fan. any other thoughts on what it could be? What vaccume line would it be?

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font class="pn-sub">Quote:</font><HR></TD></TR><TR><TD><FONT class="pn-sub"><BLOCKQUOTE> If the people lead, the leaders will follow. </BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>[addsig]

MudderChuck · #5 (**permalink**) 07-20-2003, 07:00 PM

I´m not sure about the 98 per say but the earlier models had a cable. That did have a habit of popping off of the control lever, at the dash and at the heater (cheap fasteners). The fan speed control also had a habit of acting up.

What kind of sound is the A.C. making? Bearing, thumping, or chatter. A rapid clicking, like a loose lifter, is usually a sign of potential failure.

A not quite complete charge can make them noisey. Check the flow window, while having someone else turn on the A.C. you can see the flow window filling up. If it´s not close to full, could be low pressure. High pressure will usually shut the system down, as will exceptionally low pressure.

If the charge is a little low, at idle, it will sometimes, shut the magnetic clutch on and off making a heavy click or metalic thump sound at the front of the compressor. Not particularly damaging but annoying.[addsig]

balloo93 · #6 (**permalink**) 07-20-2003, 07:00 PM

May be apples and oranges, but I had a similar problem with my GMC pickup. It ended up being the heater AC control. I would assume that the newer models use electronic controls.

Just like the fact that my 93 sport doesn't have a speedo cable and my friends 88 does. Mine is all electric. It wouldn't be that hard to see, just pull off the front cover and remove the screws holding the heater/AC control, and take a look.[addsig]

RAVEN13xxx · #7 (**permalink**) 07-20-2003, 07:00 PM

Sounds to me like the blower motor itself is giving up.[addsig]

Mudshark · #8 (**permalink**) 07-20-2003, 07:00 PM

The blower in my '88 Chief does the same thing; if I slow down from a highway speed and then speed back up, the blower stops nearly all output until I reach a cruising speed and let off the accelerator a bit. I couldn't figure it out so just decided to live with it![addsig]