Air conditioning diagnosis and repair

[Aaronams25]

My AC has 134a fittings and a small leak that i found. What i am having issues with though is getting the compressor to engage using the ac button. I jumped the ac compressor to battery and it does work and starts to pump cold air. I then jumped power to the relay and it engaged from there too. When i try to jump power to the number 7 fuse nothing happens. At this point I was lost. If power goes from the ac button to the number 7 fuse and to the relay why is nothing happening from here? I also tested for power at this fuse. Still nothing. When i test for power at the relay I get nothing aswell. I tested the relay and close the circut. It reads 0 resistance on prongs 3 and 4 when i jump power to prongs 1 and 2. the relay is fine but it isnt getting power from the number 7 fuse location. Am I missing something else here? Also I cannot locate my ac diode under the left kick panel on the drivers side. just hard to find anything up there after the alarm system was installed. If you have any info on what I should be testing for from fuse to relay or in-between please educated me. Thank you for reading.


Also I think We need a dedicated section to just ac. This is a basic but complicated system since a simple mistake can cause it to not function. Ill post pictures of what i have done and tested tomorrow before work.

[Fleetw00d]

There is a pressure switch in the high pressure line (located behind the left high beam). If the system is not sufficiently charged, the pressure switch will prevent the compressor from engaging. With the system turned on and the engine running, jump the connector for the switch, the compressor should engage.

Fix the leak, then charge the system.

[deevergote]

A dedicated section might not be a bad idea. I'd hate to create to much more clutter, but as these cars age, their AC systems are pretty much guaranteed to be in need of repair.

The only major issue is that much AC work is illegal if performed without a license and without utilizing proper disposal methods. "Take it to a professional" is hardly the answer people want to hear, and "just vent it into the atmosphere" is something I hardly want shared more than it already has been on this site!
However, things such as what you're talking about would definitely be good to have in a more compact section.

[Fleetw00d]

If he had a leak, it has already vented to atmosphere.

[F22Chris]

If he had a leak, it has already vented to atmosphere.

Yup..

You need to see if your system even holds vacuum. If it does, Fleetwood might have something on the pressure switch as the compressor won't engage with too much or too little in the system. Start with the basics.

-Recover the system. Legally.

-Put vacuum on the system to check for leaks. System should hold around 30hg

-Repairs as needed (o-rings, expansion valve, whatever)

-Add oil (ester oil is what should be used for the CB7 if doing a 134 conversion)

-Charge freon to .7 of factory r12 specs.

This is what I do at least. Fix the leak.

[deevergote]

If he had a leak, it has already vented to atmosphere.

Yes, but I wouldn't be creating a separate section just for his issue. Others will surely experience other problems, some of which will require venting the system to fix.

And f22chris, if I do make an AC subform, you're modding it. you're always on top of any AC related threads.

[Crankshaft]

One of the very first threads i created on this forum was about a common electrical problem on this cars were the circuit board on the control panel burns the section right past the light on the ON switch that allows the button to ground and the light to come on but will not complete the circuit for the system to come on, our repair back then was to grab a small piece of wire and solder it across the burnt area. We checked the one i had on the car plus the original i had in the trunk and both had this issue. Another problem on retrofits is the failure to convert the capacity of R12 vs 134a as 134 operates under different pressure, this causes the system to be over charged.

[Aaronams25]

Thank you everyone for your reply

Everyone i just got off work and oh my goodness this thread got some attention fast.

Yes I have read what everyone has written. let me put all worries to rest about my evac. When I started the conversion on the fittings I tested the low side and there was no pressure at all. I used a retro fit kit and snugged everything hand tight while using pag oil for the new rings and chuck valves for the fittings. I replaced the drier with a new one. Pag oil on those new o-rings aswell. And after that I hooked up the ac manifold gauge and pump. No i did not hold vacuum when i first checked. It read -25 and went no further. I closed the high and low side and it slowly leaked back down to 0. This was a huge disappointment. I used a dye and refrigerant mix so i could find the leak. A chuck valve was not tight enough and the ac line going to the compressor leaks. I have not yet fixed that because I do not want to evac all that refrigerant into the air. I will be getting a vacuum pump that will evac as it pumps the system. I know I should probably get this done by honda or any qualified ac repair technician. But this cb has been diy since i got her. So this is kind of important to me that I do it on my own. My next step is to properly evac the refrigerant in it and replace the o-ring that is leaking. Very very small leak i might add. I did see the pressure switch but when I tested it for voltage it read nothing. Should I jump power to that switch and see if it makes it engage aswell. I have already made the clutch engage once and mind you when I tried to jump power to the number 7 fuse that did nothing. But it worked from the relay and the ac compressor main plug. Ill take picture of everything in the Am when I get up. Hopefully imaged help to give a visual for anyone else who may be confused on where certain items may be located and look like.

[Crankshaft]

I my past experiences minuscule leaks happen on the expansion valve or evaporator, you are on the right path with uv dye so just check for leaks around there.

[deevergote]

My comments have been 100% in response to your suggestion of an AC subforum. Nothing I have said has been regarding your issue, as I don't have the knowledge or experience to help you. I apologize for the confusion.

[Aaronams25]

Follow up

Hello everyone. Just a follow up on the post that i sadly let die. A short answer to my own question in case anyone else would like to know. The chuck valve was leaking from me tightening it slightly too tight. On top of that almost all of my seals were leaking from the high side I think. Thankfully I did not find any leaks inside the cabin. But I have since deleted the A/C unit along with the bracket and most of the piping running above the transmission to the firewall. That was right before the winter fell. So She was not missed. And even though its getting toward summer im going to leave it out for now. I still have to delete the condenser though.