After having run without any issues all season, I found my A/C compressor
will not engage when I tried using it yesterday.
I checked the fuse and even tried swapping in a known good relay, no luck. I
have no schematic for checking the switch itself. I used a DVM and find no
12v at the connector to the clutch assembly.
Any thoughts on that?
On an unrelated matter, the truck is a 4x4 5.9L with just shy of 96K on the
I crawled underneath since it was in the garage anyway and tried to inspect
the steering assembly (tie rod ends etc). I have noticed some "noise" in
what I think is the front end - clunks, creaks etc.
I really have no feel what what is acceptable wear and feel at that age. The
passenger side tie rod end clunks when I apply a twist to the assembly, and
all of the contact points move freely with only that part having that clunk
associated with it.
How about your thoughts on that?
Thanks in advance!
Yep... typically this is due to a low charge. On the accumulator
(canister-looking thing on pass. side firewall, with A/C lines going to it)
is a low-pressure cutout switch. Disconnect the connector, jump the
terminals (on the harness, not the switch), and see if the compressor kicks
in. Only do this as a test, because it's designed to keep the compressor
from eating itself when there's low/no pressure (and no lube).
Anything with a ball joint on it will twist back and forth, but you should
not be able to move it up/down, side/side, or front/back. If you can, it's
worn and needs to be replaced.
I might add on the A/c clutch. the clutch uses electromagnets to engage the
pulley that is constantly being turned with the belt. I too am having
problems getting it to engage half the time, most of the time it is after it
has cooled off the interior enough to shut off the pump, but wont come back
on when it needs to start cooling again. Carefully, I discovered the clutch
was being magnetized, yet not engaging & I can carefully tap on the pulley
and it goes right in. Seems to me this means the clutch is bad, however on
my 2000, the clutch is NOT sold separately. pumps range from 400 on up it
seems, plus labor to get it all going again once you lose the cooling gas
that they pump. You should be able to test like Tom said, jumping the
harness proves that the switch didn't work or the system is low. like I
said, mine the switches were good, the clutch seems to be bad. Right now I
am waiting to double check bad grounds to engine, but I can hardly pull the
screwdriver off the face of the pump/clutch when AC is turned on (Please,
try without the engine running but with the KEY on and ac switch to on, and
any jumpers you need to test, that way you wont have the screwdriver yanked
out of your hands and through something vital on your body or truck).
better yet is a test light on the clutch wires I guess?
I found this by accident trying to jump the 2 switches one afternoon. My
screwdriver slipped from my hands and caught itself on the pulley, luckily
engine was not running at the time as well.!>!>!!
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