A/C help. So close to solving this

[jentzschman]

Ok, I am pretty sure I have the issue narrowed down on my AC issue on my truck:

When I push the ac button on the dash, the light lights up. However, the magnetic clutch does not engage.

But, when I hard wire a lead from the positive battery terminal to the connector for the magnetic clutch it engages fine and I get nice cold air, FINALLY!

So, could the ac switch itself be bad? I am in the process of investigation now, but thought I could enlist the ideas of other.

Thanks.

 

[jeeper]

When hard wiring the A/C clutch, did you bypass the pressure switch?

 

[jentzschman]

When hard wiring the A/C clutch, did you bypass the pressure switch?

Nope. Right now I have a hard wire from battery to a switch. At least for now I have ac until I can figure what why the magnetic clutch is not engaging.

I still keep the AC switch on, but I have to use the new hard wire switch to engage the clutch...

Not sure if that is going to jack something up....

 

[bryson]

If the clutch does not engage with the system wired properly, you either have a bad pressure switch, or insufficient pressure in the system (I think the latter is more likely the culprit.) If there is insufficient pressure, and you bypass the switch and force the compressor to run anyways, you will likely cause system damage - that's why the switch is in there in the first place. I'd find a shop or friend with AC gauges and have them check it out.

 

[Brad J]

You could possibly burn up the electro-magnet if its hot wired all of the time & run down your battery. I would check if there is continuity from the clutch to one of the wires to the plug at the switch to rule out a break in the wire. The switch could be bad & only will light up when pressed but not pass through the 12 Volts. I would think that if it were a blown fuse that the light would not turn on but just another thought

 

[jentzschman]

Thank you for all the advice. I think I will stop using the rigged switch. I have not been running it all the time, just here and there to see how it does.

I put in new refrigerant and on one of those gauges that comes with the recharge canister, it reads just barley above low.

I am not skilled in electronics at all. I know it may be simple, but it's just not my thing. I will have to get a meter and attempt to test the continuity of the pressure switch via the plug.

I hope its not that. I just pulled the dang unit to replace the expansion valve...

 

[jentzschman]

There should be a clutch relay, no? If so, that's the next thing to check.

I think so. Here is a weird think I noticed today while driving.

Back when the ac worked, I remember hearing (what sounded like a relay or relay switch turning on and off near the glove box)

Today, I did not notice it at all. That makes me wonder if indeed the pressure switch is bad. I would guess the switch is trigger the relay (or switch) that then in turns engages the magnetic clutch.

 

[Rogerwh0]

You can normally test the power on both sides of both pressure switches ( high and low pressure) and see where you are losing power. More than likely low freon.

 

[jentzschman]

You can normally test the power on both sides of both pressure switches ( high and low pressure) and see where you are losing power. More than likely low freon.

Cool. I will but another canister and see what that does.

 

[gertsch]

Did you check fuses? That ended up being the issue on my rig.

 

[jentzschman]

Did you check fuses? That ended up being the issue on my rig.

Yes. The ones inn the engine bay as well as the ones in the dash by the steering column. Are there more then those two places?

Sent from my HTC VLE_U using Tapatalk 2

 

[jentzschman]

Well, I think it has something to do with the wiring. I connected all the stock wiring and hit the A/C button inside the cab. As I was messing with the vent control knobs the compressor kicked on.

It would stay on for a minute then turn off. Not sure where to go from here.... but it's one step closer at least...

Any thoughts?

 

[bryson]

It still sounds like it is low on refrigerant... Have you been able to hook up gauges to the system yet?

 

[jentzschman]

It still sounds like it is low on refrigerant... Have you been able to hook up gauges to the system yet?

I have put 3 of the smaller sized cans in already.... The gauge, the ones that come with some of the cans, reads just below half of the green section.... not sure what this is as far as the exact pressure goes...

Is 3 of the smaller cans normal? Too little perhaps...?

 

[ricsrx]

is green the low and blue the next color and blue is filled?

so you have ran your compressor after the 3 cans?
what is the gauge read now?

I would cycle your compressor manually for a few minutes every day and check your readings.

see if it changes, it might change after a few days of cycling. but if it is going back down to empty obviously you have a leak.

3 cans seams a lot and not be into the blue.

I am not an a/c guy but have done a few conversions and repairs and recharges. as i get older i forget alot of details, i am sure if my facts are wrong, some one will let me know.

 

[jentzschman]

is green the low and blue the next color and blue is filled?

so you have ran your compressor after the 3 cans?
what is the gauge read now?

I would cycle your compressor manually for a few minutes every day and check your readings.

see if it changes, it might change after a few days of cycling. but if it is going back down to empty obviously you have a leak.

3 cans seams a lot and not be into the blue.

I am not an a/c guy but have done a few conversions and repairs and recharges. as i get older i forget alot of details, i am sure if my facts are wrong, some one will let me know.

White is low/empty then green then red is overcharged.

Forgive the lack of understanding, but what you you mean to manually cycle the compressor?

 

[ricsrx]

sounds like you are fully charged

Cycle it with your bypass switch, providing you still have freon in the system.
once that is stable and you know you dont have a leak, then start with the electical system.

you did state that the clutch did pull in on its own so you may not need to use your bypass switch.