Frank the Tank

[leadsled01]

Awesome bus. I also have a 1997 e350 shuttle with the ford factory passenger door. Great set-up for traveling.

[FrqntFlyer]

Christopher, It is a combined system. One of my 3 fans condenser fans is froze up (it wont turn by hand)

I know there is no refrigerant in the system.

The red LED light does come on when the switch is turned on. But the rear fans do not turn on. All of the fuses are good, frt and rear. I have checked and the fans DO opwork when they get 12V's.

Right now I want to get the fans working and then I plan on taking it to a fleet service center not far from me to service the a/c.

If anyone has any type of wiring schematic for one of these it would really help.

I was a Ford service tech for about 7 years, so I know enough to be dangerous.

[cadillackid]

on a Trans/air the whole system will fail to Operate when that red LED is on, its the low pressure switch, if you Jump the switch, the fans should come on..

on mine the Low pressure switch is up in that evaporator at the rear of the bus..

Trans/Air has been more than helpful in pointing me the direction on my system.. the 301362 condenser is the most common and they are also prone to leak.. its not made anymore..

I gave Trans/Air my VIN and they looked up the part numbers for me.. in my case I found a Line fitting has a Very slow leak.. they gave me the fitting size.. they also gave me all the capacities of the compressor, condenser, and evaporator..

they may be able to get you the wiring diagram for that unit as well.. but my guess is your fans will come on if you bypass the pressure switch.. obviously not run it like that but for testing...

the insidetemperature of the bus has to get fairly warm before the thermostat will kick the compressor on.. i found on a cool morning my unit ran a couple minutes before the compressor kicked in because the sensor felt it wasnt warm enough.. the outdoor fans on mine are tied to the compressor.. when the compressor cycles out my fans turn off outside..
a tie-in system may operate differently.. mine is a full-size school bus chassis so I have no dash air (right now... thats about to change).. and just the TransAir in the back like yours is..

the controls usually look different on a Tie-In system.. as you normally have regular dashboard A/C controls and then just a rear fan speed control for the rear A/C.. and then under the hood you'll notice around the Canister that the freon Lines Tie together...

-Christopher

[FrqntFlyer]

Thanks Chris! That what I thought about the rear blowers. All good information and definitely makes me feel better about trying to charge the system.

I will give them a call and see what kind of info I can get before I hook it to a machine and blindly shoot some unknown amount of freon into the system.

[cadillackid]

id leak test it first if you have the ability... shoot some nitrogen in if you have any.. if not.. shoot a lb of 134A in and hit it with an electronic leak tester... start at the condensor.. its the most common place to leak on those..

a brand new one that includes the fans is about $700 , but isnt a direct replacement.. thats assumking you have a 301362.. I just changed one for a friend of mine.. got lucky as he found a good used one from a bus Junkyard..

1 of the fittings was were nasty and rusty so i replaced the liquid line with Burgaflex and BurgaClip.. Burgaclip is nice kit and easy to install... I used that ony other bus where i built A/C from the ground up ..

also make sure the drain hole in the evaporator tray is clear... people dont change the filters then dirt gets o nthe coils and ends up in the drain and you get basty mildew smell .. clean that pan up and no issues..

-Christopher

[Carytowncat]

Still excites me to read of another stepping off into the bus journey.

[FrqntFlyer]

Ok. I put the gauges and a a vacuum pump and it immediately pulled down to around 15 psi. after a few minutes it was down to 27 psi. I let it run for about an hour and shut it down. When I get home ill see if it held overnight.

It may be wishful thinking.

[cadillackid]

Originally Posted by FrqntFlyer

Ok. I put the gauges and a a vacuum pump and it immediately pulled down to around 15 psi. after a few minutes it was down to 27 psi. I let it run for about an hour and shut it down. When I get home ill see if it held overnight.

It may be wishful thinking.

Vacuum is Inches of water..not PSI (29" is a Full vacuum.. 27 is partial) and is Negative pressure.. inches is a LOT less than PSI..

if a system wont hold a vacuum it definitely wont hold refrigerant.. if your system DOES hold the vacuum, then you still need to charge with 150 PSI of NITROGEN...

Nitrogen is not temperature dependent and is detectable using an ELD

DOnt use refrigerant to pressure test a system as its pressure readings will change with temperature.... not to mention its frowned on by the EPA to charge a known leaking system..

-Christopher

[FrqntFlyer]

Thanks for the information Chris.

I left it holding a vacuum for a couple of days. This afternoon I charged the system and it's blowing nice and cool. I had already cleaned out the tray/drain and made sure the hoses actually drained to outside.

Another lucky break!

Any chance you can help me find a reverse wire to tap my back up camera too? LOL!

[Stewzer55]

Sounds like you got the leak pretty well figured out and repaired if it held vacuum for days.