Red Dot AC system on M1123

[Gcelevator]

Hey guys, i am here looking for help.
While on a trip yesterday to the Florida west coast to bring supplies the belt tensioner broke and the belt strings damaged the AC compressor (Sanden 1 wire)
The tensioner issue was resolved, however i was trying to fix the AC system with no prints available to me. First question is if anyone have prints for this system.
I will explain the issue and probably someone can help as well. I kinda fixed the stripped wires behind the clutch with skrink tube, and the red dot diagnostic is flashing 3 times which is check compressor clutch.
I measure the wires agains ground (both disconected) and it is not shorted to ground. The coil measures 19 ohms (not sure what should be) when i disconnect the wire from the compressor coil and i measure i assume i should have 24VDC and i got nothing.
I have to mention that the positive wire feeding the AC unit almost burnt and the breaker did not trip.
All this leads me to believe that the diagnostic box might be damaged or shorted as i believe this must provide 24VDC to start the compressor, unless i am totally wrong. I did not want to apply 24 volts durectly to the compressor as i am not sure how it works.
Anyone has an idea? Guides? Help? Will be very much appreciated.

 

[Mogman]

If the AC was on then you likely shorted out the compressor clutch wire at least momentarily to ground, hopefully there is a fuse in the compressor circuit otherwise you likely fried one of the components that feeds the clutch, Yes a schematic would be very helpful, sorry can't help there.
One other possibility is that system was smart enough to detect the short and shut down the comp circuit, a power reset might help.

 

[Mogman]

Hey guys, i am here looking for help.
While on a trip yesterday to the Florida west coast to bring supplies the belt tensioner broke and the belt strings damaged the AC compressor (Sanden 1 wire)
The tensioner issue was resolved, however i was trying to fix the AC system with no prints available to me. First question is if anyone have prints for this system.
I will explain the issue and probably someone can help as well. I kinda fixed the stripped wires behind the clutch with skrink tube, and the red dot diagnostic is flashing 3 times which is check compressor clutch.
I measure the wires agains ground (both disconected) and it is not shorted to ground. The coil measures 19 ohms (not sure what should be) when i disconnect the wire from the compressor coil and i measure i assume i should have 24VDC and i got nothing.
I have to mention that the positive wire feeding the AC unit almost burnt and the breaker did not trip.
All this leads me to believe that the diagnostic box might be damaged or shorted as i believe this must provide 24VDC to start the compressor, unless i am totally wrong. I did not want to apply 24 volts durectly to the compressor as i am not sure how it works.
Anyone has an idea? Guides? Help? Will be very much appreciated.

Sorry after re-reading your post I would think you do have a fried component, it looks like the breaker was too large or defective and did not protect the system

 

[Gcelevator]

If the AC was on then you likely shorted out the compressor clutch wire at least momentarily to ground, hopefully there is a fuse in the compressor circuit otherwise you likely fried one of the components that feeds the clutch, Yes a schematic would be very helpful, sorry can't help there.
One other possibility is that system was smart enough to detect the short and shut down the comp circuit, a power reset might help.

Hey Mog, thanks for getting back to me. I have tried everything, power down, disconnect batteries, traced wire by wire and nothing. The only thing i noticed was the Positive wire feeding the unit from the batteries fried, not sure why the breker did not trip.
The compressor does not seem to be shorted but i am not sure if 19 OHMs is normal. I believe the diagnostic box is fried. I dont know, i will try with a V belt compressor i have and see.

 

[Mogman]

Hey Mog, thanks for getting back to me. I have tried everything, power down, disconnect batteries, traced wire by wire and nothing. The only thing i noticed was the Positive wire feeding the unit from the batteries fried, not sure why the breker did not trip.
The compressor does not seem to be shorted but i am not sure if 19 OHMs is normal. I believe the diagnostic box is fried. I dont know, i will try with a V belt compressor i have and see.

I think your compressor is fine, go ahead and try feeding it 24V to one wire with the other grounded and see if the compressor comes on.
19 ohms sounds about right, IIRC the 12V clutches pulled about 3A, so the 1.3A calculated at 28V sounds about right.
I would look real hard at that breaker, it should have tripped before the wiring fried, I think your suspicion that the control box is damaged is valid.

 

[Gcelevator]

@Mogman, not sure if you want to keep these in the sticky. Thwre is no schematics but the instructions in how to install and the last page shows the amount of frein and oil to add.
I went to the office to check since i bought a new red dot system as spare and it is a little bit different. The diagnostic box is nowhere to be found. Probably is inside as i did not see the big connector for it but had the kids and wife in the car and didn't want to stay too long. Tomorrow i will open up and find out if the box is there. Ki d of weird to place it inside as you want to look at the lights to follow troubleshooting. No schematics inside of the box for sure.

 

[Gcelevator]

This second one is for the M998 and M1038. Almost the same instructions but the freon amount is defferent.

 

[Mogman]

This second one is for the M998 and M1038. Almost the same instructions but the freon amount is defferent.

PM sent.

 

[Gcelevator]

Problem has been sold, the diagnostic electronic box was damaged. Bought a new one and is working flawlessly now.
Bummer, the new red dot system y have in the office doesn't have the diagnostic box and no conector for it. It looks like the newer style is connected directly and probably not the best design. Even though the box seems like a week point, it is very helpful to diagnose AC issues. Oh well..

But now, another issue, it looks like my smartbox (not so smart) is taking a dump, i have to check which one it is but i know is a yellow label.
For sometime now, it is not recognizing when the truck is hot and today in 2 ocasions i had to turn yhe truck off and on again as yhe light was not turning off. AC was not coming on and alternator was not getting out of the yellow line. More troubleshooting ahead.