Trans air. Condenser fan relay location help

[BigAlFlorida]

I’m working on a 2012 Chevy 3500 van chassis with an el dorado shuttle bus conversion rear. Having an issue of the condenser fans staying on after the key is turned off. I searched and this sight gave me some great trouble shooting advice. The thermostat switch in the dash is functional and I cannot currently get the problem to show itself. I’d like to locate the fuse/ relay panel for the rear trans air unit. Any ideas on where it might be hidden? There is a panel above the driver seat but it doesn’t seem to service the rear hvac in any way. I’ve checked the perimeter of the bus underneath with a light and mirror and have not found any relays or fuses. The wires from the switches go into the firewall or I lose them in the under dash spaghetti. I have yet to remove the wall panel behind the drivers seat or taken the cover off the rear roof mounted unit. Any ideas on where to look? Thanks in advance.

[Rucker]

Is it possible that the fan runs even after the rig is turned off if the lineset temperature is still too high?

[BigAlFlorida]

I considered that but the thermostat switch when turned all the way to the left. There is a click and when tested with the multimeter has no continuity in that position. After reinstalling the thermostat switch the issue has not re surfaced but according to a similar thread on this forum. After the switch there is a really for these fans somewhere and I would like to find it in case the problem resurfaces. Thanks for the reply.

[BigAlFlorida]

I will also add that this is a trans air unit and I have tried to call there numbers listed on the equipment but seems the number is not valid anymore

[cadillackid]

Trans/AIR normally locates their relay panel in a box under the bus... on my red bus its actually oddly out in the open.. and yeah things get wet and need rep[laced on it..



theres no thermostat switch on thew Trans/AIR units.. the condenser operates anything the compressor engages.. on a van cutaway that can be when the rear unit is off if this is a Tie-in system (90% are).. so if you are using only the front A/C, front Defrost, front Bilevel your compressor can come on.. (thats controlled by the original Van selector switch (looks like a car A/C)..)


the condenser fan should never run when the bus is turned off so its likely as you think, a stuck relay..


id look for the panel in the battery box, sometimes in a box on the back deck.. ive found them under the bus.. follow the wiring harness from the under-body condenser it should lead you there to it...



Trans/.AIR is still in business and will have that whole A/C system logged in their systems by your bus VIN.. and may even have service documents for you if oyu cntact them. I have bought parts a couple times from them for mine..