Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

how to fix AC

rmalottwtes30 on Sat April 26, 2008 9:33 PM User is offlineView users profile

Year: 1985
Make: Ford
Model: f250
Engine Size: 6.9

I have a 85 ford f250 with a 6.9 diesel, When I bought the truck I was told the Ac didnt work, ok I took the belt off the compressor anyways. Id like to get the AC working good. Where do I start?

brickmason on Sat April 26, 2008 9:54 PM User is offline

First of all turn the compressor clutch by hand, the outer part , not the part the belt rides on.

Is it smooth with no rough spots after turning it a whole round. If so then its probably ok. Your truck has the FS6 compressor. The best compressor you will find on a Ford, so start there.

-------------------------
Just another brick in the wall

Had a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil

rmalottwtes30 on Sat April 26, 2008 10:03 PM User is offlineView users profile

ok if it is bad how much would one be?

If it is ok then what next? just needs charged?

brickmason on Sat April 26, 2008 10:10 PM User is offline

Hook a set of gauges to it and see if it holds any static pressure.

If so then you may just have a small leak somewhere. If its say 80 degrees out and your pressure is something like 30 psi. then a topping off of refrigerant may be all you need. This system is R12 unless its been converted to 134a.

-------------------------
Just another brick in the wall

Had a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil

rmalottwtes30 on Sun April 27, 2008 3:26 PM User is offlineView users profile

Ok did a little testing we turned on the truck and turned it to AC high and the clutch on the AC pump is not locking up, we went and got the test light out and neither of the two wires are getting any juice. The accumulator is getting juice but the wires from there are not getting juice to the Pump. Also we noticed over by the accumulator what looks like a broken off prong.

brickmason on Sun April 27, 2008 4:44 PM User is offline

Thats the cycling switch at the accumulator. Low refrigerant charge will stop this switch from activating the compressor.

I assume you dont have any gauges, so unplug the cycling switch and jumper the 2 wires then feel of the accumulator. If it gets cold within a minute and starts blowing cold air from the vents then change the switch. But dont leave it jumpered any longer than a minute, if it does not get cold, because the oil will not migrate through the compressor due to low refrigerant charge.

Cycling switches on those year model Fords are common to fail.

-------------------------
Just another brick in the wall

Had a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil

bohica2xo on Sun April 27, 2008 5:58 PM User is offline

That red board with the terminals on it is the blower resistor. It should have the following connections on it:

1) Black. 2 wires on this terminal, one wire from clutch, one to ground.

2) Orange / black. One wire, to blower motor. Lowest blower speed

3) Light Blue / orange. One wire, to blower switch. Blower speed low/med

4) Red / orange. One wire, to blower switch. Blower speed med/high

Your blower resistor does not appear to have all 4 connections on it, and a terminal may have burned off. This is a 30 amp circuit, and this kind of failure is not uncommon. Look nearby for a dangling wire with a remnant of a terminal in the connector...

A replacment blower resistor is available at your local auto parts store.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

rmalottwtes30 on Sun April 27, 2008 6:02 PM User is offlineView users profile

Well ive talked to some other people on FTE and they said its normal. I was also told to jump the wire over to get the AC compressor clutch to click in and when I jumped it the clutch kicked in. I also realized my system is very low on r-12. I learned also r-12 is not available to public and I plan on converting to r-134. How much could I expect to spend to convert?

So it was just the low refrigerant keeping it from working

bohica2xo on Sun April 27, 2008 6:16 PM User is offline

What exactly is "normal" about your vehicle?

The low pressure switch can be jumpered briefly for testing, but should NOT be jumpered out for charging. A low charge or a bad switch has the same symptoms, so pressure gauges are necessary for proper diagnosis.

R12 is available, you simply need to take an online (open book) test for "certification".

I would not convert that vehicle to 134a. I would replace the fan clutch if it has more than 60k miles on it. A new dryer, some clean-up & a fresh charge should put it right.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

rmalottwtes30 on Sun April 27, 2008 6:44 PM User is offlineView users profile

they said the broken prong is normal and not used. How do you go about taking this test for r-12?

mk378 on Sun April 27, 2008 8:35 PM User is offline

As long as the blower works on all speeds the resistor is OK. You will certainly want the highest speed working when summer comes.

There is a link to one testing company in the "Procedures Tips and FAQ" section of this site. They seem to be a good deal at only $15.00. There are also other companies easily found with google. Once you have your EPA number you can buy R-12 online or in some local auto parts stores that still carry it. It is somewhat costly to buy enough R-12 to charge a full-sized truck, but those old GM's really don't convert well.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.