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I'm told by a MotorPool veteran of 20 years that "soft cab" trucks were basically never equipped with AC. He couldn't recall ever seeing one in fact. The A1P2 armored cab trucks all have it and in fact AC malfunction is a deadline. The AC only has to drop the ambient temp by 20 degrees F to be considered operational though (generally they work much better than this spec).
So far I've got the cab evap unit installed, the condenser core installed, and the compressor installed. Currently working on hoses and routing the last of the wiring.
The cab unit required that I make a template and drill 4 holes - two for the AC fittings and two for the rear most evap drain tubes:
Fitment was excellent though and basically fits like it was designed to be there:
Notes:
1. You will need a helper. With the cab lowered you can access the front four bolts from the grill area (remove the grill), but someone needs to be on the inside to push the unit forward against the foam and so forth to get the bolts started.
2. The wiring in the back needs to be carefully zip tied away from the wiper linkage.
3. The brake controls will move up and back and all the lines to the controls will need to be replaced and extended by about 3.5-4" for push-connect fitting trucks. If you have the older ferrule connections then measure carefully. I was able to make the lines and route them through the maze of hoses and wiring on the bench - be careful to avoid the electric flapper actuators, sharp hose clamps, etc. On the C7 controls the exhaust vent is not routed to the bottom of the cab but instead has a sintered brass filter/muffler installed directly on the controls - this might be a useful mod for those with older trucks.
4. The floor HVAC hoses.... The driver's side can use the supplied adapter that twists into the box, but the passenger side required the use of the old adapter from the original heater box. Bending the tabs a bit and then crushing it slightly oval was all that it required. Reason being the proximity of the Transmission Control Module won't allow the longer adapters supplied with the new HVAC cab unit.
The condenser install was really straightforward. Had to drill two holes in the skid plate mounting brackets but otherwise it bolted right up with no modifications.
Onto the compressor:
Ran into an issue with the bolt hole alignment on my reproduction compressor mounts:
It appears the bolt holes were never going to line up - in the first place the lower/rear plate hits the compressor mounting boss long before the bolt holes line up anyway. And no the lower/rear plate can't go behind the front/upper plate - it's all wrong if you try that. So........
Moved the holes and bolted it all up. Notes:
1. The air compressor coolant line had to be re-routed. Also added a cushioned loop clamp at the bottom of the timing gear case to push it up so it will not rub against the compressor bracket or other objects. It's tight.
2. The coolant tube from the fill tank is in the way of the AC belt tensioner. This required removing the cushion loop clamps from the transmission cooler, shoving the tube farther into the connecting hose on the engine side, and pushing it back behind the oil fill pipe. Note that this blocks the upper AC bracket/air compressor mounting bolt so that needs to be secured first.
3. The wiring harness must move forward of the air compressor coolant hose so it's between the oil fill pipe and the coolant hose. The cushion clamp got moved up one bolt hole position on the timing case.
It's all worked out so far. Just a LOT of modification for the compressor fitment. The rest is hose routing and some wiring hook ups. Should be relatively easy from here.
So far I've got the cab evap unit installed, the condenser core installed, and the compressor installed. Currently working on hoses and routing the last of the wiring.
The cab unit required that I make a template and drill 4 holes - two for the AC fittings and two for the rear most evap drain tubes:
Fitment was excellent though and basically fits like it was designed to be there:
Notes:
1. You will need a helper. With the cab lowered you can access the front four bolts from the grill area (remove the grill), but someone needs to be on the inside to push the unit forward against the foam and so forth to get the bolts started.
2. The wiring in the back needs to be carefully zip tied away from the wiper linkage.
3. The brake controls will move up and back and all the lines to the controls will need to be replaced and extended by about 3.5-4" for push-connect fitting trucks. If you have the older ferrule connections then measure carefully. I was able to make the lines and route them through the maze of hoses and wiring on the bench - be careful to avoid the electric flapper actuators, sharp hose clamps, etc. On the C7 controls the exhaust vent is not routed to the bottom of the cab but instead has a sintered brass filter/muffler installed directly on the controls - this might be a useful mod for those with older trucks.
4. The floor HVAC hoses.... The driver's side can use the supplied adapter that twists into the box, but the passenger side required the use of the old adapter from the original heater box. Bending the tabs a bit and then crushing it slightly oval was all that it required. Reason being the proximity of the Transmission Control Module won't allow the longer adapters supplied with the new HVAC cab unit.
The condenser install was really straightforward. Had to drill two holes in the skid plate mounting brackets but otherwise it bolted right up with no modifications.
Onto the compressor:
Ran into an issue with the bolt hole alignment on my reproduction compressor mounts:
It appears the bolt holes were never going to line up - in the first place the lower/rear plate hits the compressor mounting boss long before the bolt holes line up anyway. And no the lower/rear plate can't go behind the front/upper plate - it's all wrong if you try that. So........
Moved the holes and bolted it all up. Notes:
1. The air compressor coolant line had to be re-routed. Also added a cushioned loop clamp at the bottom of the timing gear case to push it up so it will not rub against the compressor bracket or other objects. It's tight.
2. The coolant tube from the fill tank is in the way of the AC belt tensioner. This required removing the cushion loop clamps from the transmission cooler, shoving the tube farther into the connecting hose on the engine side, and pushing it back behind the oil fill pipe. Note that this blocks the upper AC bracket/air compressor mounting bolt so that needs to be secured first.
3. The wiring harness must move forward of the air compressor coolant hose so it's between the oil fill pipe and the coolant hose. The cushion clamp got moved up one bolt hole position on the timing case.
It's all worked out so far. Just a LOT of modification for the compressor fitment. The rest is hose routing and some wiring hook ups. Should be relatively easy from here.
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