M923 air conditioning a/c install project

davo727 said:

Were your condenser fans on steady during the time you took those pressure readings?

edit- The fans need to be on if the AC is on. Condenser needs air flow over it, would make it impossible to tell whats going on as far as charging it correctly if the fans were kicking off thus allowing the high side pressure to go through the roof.

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Condenser fans are on all the time.

Hey, this truck looks familiar. I miss PATROL / BAT 2. Ill see you in a few weeks!

General rule of thumb for R134a is 2 times ambient temp, plus 20% on the high side. So, using 95F, you should be seeing about 230psi or so, and producing an air vent discharge of about 50F.

R Racing said:

Mine ended up needing 4 75 lbs. Not sure why because they guy charging it was freaking out. But it kept dropping out on low pressure til there was that much in the system? ??

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The instructions for my M915 kit says it needs 4.75 pounds.

The hwwmv instructions didn't give a amount to put in so we filled it til we thought it was working correctly lol

My HWWMV kit says on the back page 4lbs 5oz and the other instructions says 4lbs.

subbing in to this thread, need to add a/c to my 931

The instructions that you have posted are not for the A2. Do you need A2 instructions?

loco said:

The instructions that you have posted are not for the A2. Do you need A2 instructions?

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Will be doing an A2 but Kenway has a six-week backlog for delivery of the bracket. I have some Reddot M915 kits now and am looking into using its bracket as a possible starting point.

Hey over. During the ac installation process, did you allow the drier to sit uncapped for a long time? This would introduce excessive amounts of humidity into the system and reek havoc on the system. Your high side should not be above 300.

For those considering AC installation in their M939s, be aware that the alternator will need to be upgraded to a 100 amp or >unit. I've suffered multiple electrical system faults due to alternator not liking the additional load. So far I've replaced the ABS ECU, the fail safe module, and the alternator. I might also need to replace the PCB due to recent symptoms. I am currently in the process of acquiring a 200 amp alt to power my M923A2. Good luck to all.
The AC works flawlessly and cools well. However, after a 10 min drive, the 60 amp alternator goes in to an overvoltage condition which will/has damaged electrical components. My Hawker batts are in good shape, so alternator voltage dump doesn't seem to be the case.
Any electrical experts on here care to shine light on this issue?

jetjockB747 said:

Hey over. During the ac installation process, did you allow the drier to sit uncapped for a long time? This would introduce excessive amounts of humidity into the system and reek havoc on the system. Your high side should not be above 300.

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Did not leave the dryer uncapped. I think high side can go to 325-350 when the temps are 115 here.

Weird? We've driven all over with no issues. Voltage is in the green and running fan on high. I believe I have a stock alternator. What and how much is the one your going to?

I'll be installing a Niehoff 14/28V 200 amp alternator. I'm guessing that the additional amp draw to charge my 4 batts might be too much for a 60 amp alt. and the RD AC system.

Over said:

Will be doing an A2 but Kenway has a six-week backlog for delivery of the bracket.

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Do you have the contact info for Kenway? I've got the HMMWV kit for my A2 and just need to get one of those brackets ordered so I can get it going.

mkcoen said:

Do you have the contact info for Kenway? I've got the HMMWV kit for my A2 and just need to get one of those brackets ordered so I can get it going.

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I beleive somewhere in this thread I posted the phone number. Google it and it wil come up. The bracket runs a bit under $800.

Over said:

I beleive somewhere in this thread I posted the phone number. Google it and it wil come up. The bracket runs a bit under $800.

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$800 for a flipping bracket??? I thought somewhere in this thread it was mentioned for around $250. For that amount of money I'll just set an ice chest on the seat with a fan over it.

mkcoen said:

$800 for a flipping bracket??? I thought somewhere in this thread it was mentioned for around $250. For that amount of money I'll just set an ice chest on the seat with a fan over it.

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Your in TX so I can't say it doesnt get as hot as AZ. That's why on the M915 kits I have I am going to try to adapt a bracket. The big deal I think is getting a pulley on the motor somewhere to run the compressor.

Over said:

Earlier in the thread I mentioned I got mine from Kenway. Look and you'll find the model number and price. Can't remember off hand. I hear they have one for the M923A2 for $220 also. HE double hockey sticks the 2 belts included are worth $40!

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So here's where I read the price earlier. Where did the $800 price come from?

Edit: Never mind. Found the later post with the updated price.

mkcoen said:

So here's where I read the price earlier. Where did the $800 price come from?

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The A0 brackets are $200. Originally I thought the A2 brackets where the same. I called Kenway and talked to the guy that designed them and got the reason and the price. On ebay there are brackets for that motor but not the military profile, they run $350 I think but put the compressor where it won't fit in an A2. Will in CT says he's acquiring a variety of brackets and may come up with some that work. Lucky for me I have 3 A0's in the yard. But I am picking up a A2 so I ordered a bracket from Kenway anyhow, we will see.