A/C Issue

[AzzLyp]

Just swapped in a different engine into my 98 gt and now that the new engine is in, the A/C isn't working any more. Yesterday I ran the engine and with the A/C in the "max" position, I saw the clutch on the compressor kick on for a second or two and then kick off - it did this twice and then didn't come on again. So I took a wire and jumped the clutch on the compressor and the A/C kicked on and the air immediately started blowing ice cold out of the vents. While it was running, I made sure to check the pressure in the lines and it was all in the "green" on the gauge. It seems to me like I'm losing something somewhere between the switch on the dash and the compressor.
I need someone that knows the system better than I do to point me in the right direction. CCRM maybe? How do I check the relay in that? I saw a youtube video on how to replace the relay in that, but I don't know at this point whether it's actually bad or not. Hell, it may be something as simple as not having connected something when I replaced the engine. I also have noticed that the idle isn't kicking up when the A/C is turned on, so I'm not getting a signal anywhere when I turn the switch on in the dash.

 

[lwarrior1016]

Ok, here we go lol. Inside the ccrm is the wot cut off relay that shuts the a/c off at wot. Then you have the low side switch and the high side switch. Try jumping the low side switch and see if the compressor comes on and stays on. If it does, you're either low on refrigerant or the switch is bad.

 

[AzzLyp]

Ok, here we go lol. Inside the ccrm is the wot cut off relay that shuts the a/c off at wot. Then you have the low side switch and the high side switch. Try jumping the low side switch and see if the compressor comes on and stays on. If it does, you're either low on refrigerant or the switch is bad.

Well, the one thing I do know for certain is that the pressure is good. I was able to jump the clutch and get ice cold air out of the vents and at that time, I checked the pressure with a gauge. I'm just unclear how it went from working perfectly about 5-6 weeks ago and then not at all from one engine to the next. It's like I knocked something loose. I doubt I fried something too because the very first thing I did was disconnect the battery when I started removing the old engine. One thing I didn't add in the op was that I went from a 2v to a 32v with a cobra manifold and it has a lincoln iacv on it. I'm using the lincoln iacv because it wouldn't idle or run right at all with the gt or cobra iacv. With this one, it runs great. I wouldn't see how that should affect anything though - the a/c wasn't kicking on with the previous iacv's either.

 

[evilcw311]

If your jumping it out at the low pressure switch and it comes on then it's either your low on freon or that low pressure switch is bad.

Low pressure switch is a normally open switch that just shorts the wires together when pressure drops.

When doing the swap even though you didn't disconnect all the lines doesn't mean that all the flexing or whatnot didn't cause you to loose a lil thru small leaks.

Also, if your not using a true manifold gauge then your not getting an accurate reading. The gauges on refill kits are garbage.


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[lwarrior1016]

^ that's right. The plastic gauge that only measures the low side is not even close to being accurate. A set of manifold gauges that hook up to low side and high side will give a better reading, even if they are harbor freight specials. There is a way to wire around the ccrm if we get to that and need to do that, I'll dig up my schematics and we will sort that out.

 

[evilcw311]

I don't think it's the ccrm of he shorted out the low side plug. That means the ccrm was doing its job and the low side sensor is the problem or the pressure is still to low.


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[AzzLyp]

I'll go in the morning and pick up some gauges from Harbor Freight. I can handle not having a/c but I cart my kid around and I don't want her in the upcoming heat.

 

[lwarrior1016]

I don't think it's the ccrm of he shorted out the low side plug. That means the ccrm was doing its job and the low side sensor is the problem or the pressure is still to low.


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I agree, I don't think it's the ccrm either. He said he jumped the compressor clutch, I was wanting him to jump the low side switch.

 

[AzzLyp]

I agree, I don't think it's the ccrm either. He said he jumped the compressor clutch, I was wanting him to jump the low side switch.

I'll jump the low side switch and see what happens. Should I still pick up the gauges if it kicks on when I jump it?

 

[lwarrior1016]

I'll jump the low side switch and see what happens. Should I still pick up the gauges if it kicks on when I jump it?

If it kicks on and stays on, it'll either be a bad switch or low pressure. It wouldn't be a bad idea to get a set of manifold gauges.

 

[AzzLyp]

If it kicks on and stays on, it'll either be a bad switch or low pressure. It wouldn't be a bad idea to get a set of manifold gauges.

Well, I picked up a gauge set, haven't opened it yet though. Jumped the low pressure switch and nothing happened. Found something else that I needed to mess with so I didn't get to check anything else though. High pressure switch next. Then maybe CCRM relay? I pulled the switch in the dash just to make sure I didn't knock it loose and it looks just like it did before.

 

[lwarrior1016]

Next would be to check the high pressure switch and then the ccrm relay. I would be more prone to go for the switch than the ccrm. I dont know exactly how to check that switch though.

 

[AzzLyp]

Next would be to check the high pressure switch and then the ccrm relay. I would be more prone to go for the switch than the ccrm. I dont know exactly how to check that switch though.

Well, I know it's a 4 pin and that I need to jump the low pressure switch when I jump the high pressure switch. I just need to find which 2 wires to jump on the HP switch.

 

[AzzLyp]

I checked both of the switches for voltage and have voltage across the pins I was supposed to have voltage to, so that only leaves 2 things - pressure and ccrm. I checked the red wire on the ccrm for voltage and it had voltage. Grounded pink/yellow wire on the ccrm and got nothing... Might be the ccrm at this point, but until I check one more wire on the ccrm, I cant completely condemn it. Pressure was only 20 on the low side, but it was also only about 75 degrees out when I checked it. I'm going to add a little bit of refrigerant in the morning and if that doesn't help, I'm pulling the ccrm and checking the remaining wires.

 

[lwarrior1016]

Do you have a schematic of the ccrm? If not, I can get one for you this afternoon. Also, when you checked the pressures you had the a/c clutch running right? The compressor should be engaged to give a good pressure reading.

 

[AzzLyp]

Do you have a schematic of the ccrm? If not, I can get one for you this afternoon. Also, when you checked the pressures you had the a/c clutch running right? The compressor should be engaged to give a good pressure reading.

Yessir, I jumped the clutch to make it run and got the working pressure. Low side was 20 and high side was 195, I think. I don't have a schematic for the ccrm, I was working off of a thread I found in stangnet where a dude had outlined which wires in the ccrm did what.

 

[AzzLyp]

It turned out to be the ccrm. I pulled it from the fender well and the board is fried under the relay. Completely wavy and burnt. The one that was in my car was replaced at some point too because it has a manufacture date of 2010 on it. Getting a new one today. Let's see how this goes.

 

[AzzLyp]

Replaced the ccrm and still no a/c... This is getting weird now. Voltage to low pressure switch but when jumped no action at compressor. Good ccrm now, voltage at high pressure switch. Still no a/c. Either I missed a ground or have a shitty ground on my harness.

 

[evilcw311]

1) check insurance coverage
2) douse car in gasoline
3) light match
4) collect check and buy Stang with ac.



Sorry, that's all I got left. Lol


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[AzzLyp]

1) check insurance coverage
2) douse car in gasoline
3) light match
4) collect check and buy Stang with ac.



Sorry, that's all I got left. Lol


This message courtesy of crapatalk!

Lol. I just found out something promising actually. Immediately after I installed the ccrm, my check engine light came one. I ran the code and it's p0117 or coolant temp sensor fault. I just read that the pcm can command the compressor off with this code because it thinks the engine is overheating. I'm looking for my spare sensor now and the harness plug to replace it with because mine is looking ratty.