I am pretty sure my problem is the compressor,but I want more expert
opinions before going ahead and buying one.
I have an 01 Dakota,3.9L 65000 miles. The AC is blowing neutral to warm
air.I checked the refrigerant level,I get 45-55 psi on it while the
compressor is under load,which is pretty good if memory serves me right. I
checked the fuses,all good.
Is there anything else it could be or other things that go bad a lot in this
model and year of Dakota? Had I read the forums last year when i bought it
used,I wouldn't have bought it :( but I gotta make the best of it now.It
runs well,just is hot as hell now.
No - a high-side R134 gauge goes up to around 400psi. Typical readings are
in the 250psi area. The quick-connect is a different size, to prevent you
from using a low-side gauge/hose, and doing damage (mostly to the gauge,
some to you).
yeah I was just reading that on a google search,i knew i remembered a red
guage somewhere. Now I gotta decide do i buy a guage or take it in,where
they will probably charge me just as much for diagnosis.
Is there really anything else it can be other than the compressor that
breaks a lot on these damn dakotas?
Are you sure that the compressor is actually running. Is the clutch
engaging when you turn it on. I have seen many people that think that just
because the pulley is spinning that the compressor is turning as well when a
quick look at the center of the pulley showed that the clutch was not
working and nothing was moving.
If at first you don't succeed, you're not cut out for skydiving
If the clutch is cycling on-and-off then I question the accuracy of
your low side pressure measurements.
First thing you need when working on an AC system is a manifold gauge
set. It'll cost about $100 for a cheapo set w/hoses at an autoparts
store. A shop will charge you more than that to open the hood so it's
a small investment. You'll probably need a can tap and a hose for the
Eventually you'll need a vacuum pump.
If the clutch is fast cycling then what you'd probably see with a
proper gauge on the low side is a starting pressure around 60PSI, then
the compressor clicks on, the pressure drops to around 22PSI, and the
compressor clicks off. Then the pressure rises until the compressor
comes on again. Repeat.
That is an indication that the system is low on refrigerant. You
don't say how long this has been a problem. It is normal for a 7 year
old car to be a little low on refrigerant (some will argue). If it
was serviced a year ago and now it's low then something is leaking and
needs to be fixed. AC shops have sniffers and UV light setups that
can diagnose a leak better than a do-it-yourselfer can. Dumping a can
or two of refrigerant in every month is wasteful and irresponsible and
is why we can't buy R12 anymore.
Two things to be aware of when working on AC systems:
1. After you buy the tools, your family/friends will want you to fix
their air conditioners.
2. You can blow yourself up if you don't know what to do. Simply
turning the wrong valve can make the refrigerant can in your hand
explode. Not to mention working in close proximity to a running
engine. Be careful. Do more research.
I had a '02 Dakota for several years and never had a single problem
with it. It was a great truck. If it weren't for the gas mileage I'd
still have it.
Thanks alot for your extensive reply.The clutch does seem to fast cycle,runs
for maybe 5 seconds,stops for 10 or 15 then same thing over. I wasnt aware
that it should be 60psi on the low side when it is running,I was looking
atthe package of the guage i bought which said 35-45 is good,I should have
consulted a dakota book.
I had a can of refrigerant I was trying to put in,but when the compressor
would cycle on,the guage went up to 70-80psi which was red on the guage and
I was afraid i would blow the can up,thus i figured it was full of
I hate to pay someone $100 to diagnose it being low on R134a.
I like the truck,but the mileage is killing me at $3.15 a gallon this week.
I will try and get the guage on it again this weekend when i am off and see
wht i can figure out.Thanks again!
When fully charged, the low side tends to hover around 25 PSI, but
it's not as simple as just that. At idle the compressor usually runs
STOP!! It sounds like you have your gauge hooked up to the high
side! The fittings are different so I don't know how it could
happen. When the compressor kicks on the pressure on the low side
should drop. The high side pressure will increase greatly. If you
plug a can into the high side, it will explode!
For $100, a shop should be able to tell you why it is low, which is
more important. There are handheld devices that detect trace amounts
of R134a. If the shop doesn't have one then find a shop that has the
No doubt. I had an '02 Quad Cab 5.9L and it drank fuel at 12 MPG!
There's no reason for any vehicle to use that much gas. Even a full
size 5.9L Ram gets better mileage. It was a great truck but I
couldn't afford to drive it.
Be careful! If you're not 100% sure what you're doing then pay a shop
to risk taking a face full of freon and metal shards. Years from now
you don't want to explain to people that you're blind because you
tried to save a few bucks on air conditioning. (You're wearing safety
goggles and gloves, right?)
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