Transair boards -- how to find out what goes where?

[SurfingDog-SKO]

09 international - having a few minor problems that may not even be problems, but I have two transair units - one front and one rear. Are these strictly a/c? The reason I ask is because I have two switches that have modes for heat along with temperature control that goes up to 80. When I set to heat the front unit's fan stops but the rear continues to run but isn't warm.

Now the next question is that during demo I was removing the dash panel on the passenger side to fix an issue with the paneling sticking out and only held together with one screw. I found three transair relay boards with the covers dangling due to someone previous breaking off the mounting screws since they seem to be 4mm or 6mm screws. The center board has a disconnected red and orange ring terminal wire on the right side that I'm unsure what it'll go to. How can I find out what these go to?

The front unit looks like so; excuse the blurriness it's a frame from a video

 

[cadillackid]

I cant read any of the data off of those aluminum covers so im just guessing..
it looks like an EC 4.0 control..



2 separate systems but sure looks like there is a 3rd indoor unit ..maybe a dash air? maybe one of them is a dual blower? you have 3 boards and 2 control sets which trans / air supports.. one on the right appears to be a slave.. not sure why the one is discnnected.. maybe it quit and they didnt want to have it run accidentilly?



https://www.transairmfg.com/bus-air-conditioning-support-documents.cfm#



https://www.transairmfg.com/pdfs/5031200 (G).pdf

 

[cadillackid]

heat - the controls are heat capable but most times on a bus there wont be any heat installed..it would be rare for them to hook up heat on those units... the heat is typically separate and is the floor heaters on the bus

 

[SurfingDog-SKO]

I cant read any of the data off of those aluminum covers so im just guessing..
it looks like an EC 4.0 control..



2 separate systems but sure looks like there is a 3rd indoor unit ..maybe a dash air? maybe one of them is a dual blower? you have 3 boards and 2 control sets which trans / air supports.. one on the right appears to be a slave.. not sure why the one is discnnected.. maybe it quit and they didnt want to have it run accidentilly?



https://www.transairmfg.com/bus-air-conditioning-support-documents.cfm#



https://www.transairmfg.com/pdfs/5031200%20(G).pdf

The covers are "TRANS/AIR 701521 REV B 47584 12/09" on each. Now you say that I think the aluminum box below the panels is the third A/C unit as it has a label that has the part number 2021993.


The front (not under the dash) air unit only works when the middle mode is enabled on the switch panel. I'm checking out the transair support documents and will likely give them a ring on Monday to see if they can be of any help to at least try to explain the layout of the system.



Here's a few close ups of each board going from left to right;

2.

3.

Looks like it's an EC3 board due to having three horizontal fuses opposed to two fuses stacked vertically. Going through them one by one trying to piece everything together lol

 

[SurfingDog-SKO]

Was about to make another thread when I found this one thinking it was another person!

I managed to definitely find out it's EC3 and there is a front mount TA96 unit with an FM55 in the rear. The dash has dual A/C and heat. Found this; https://www.transairmfg.com/pdfs/002442A.pdf which leads me to find that the error LP pops up for the rear unit. Zero fans kick on, fuses look mint. Going to drop the units to inspect.

 

[SurfingDog-SKO]

Ok so I managed to find the proper schematics and run it all down. All fixed except the far rear! But no biggie I'll get it going with time. The rear of the PCB had an exploded trace from the mosfets that drive the evap motors and I ran a nice jumper wire (coated) across the trace, all is good! I learned International actually wired this up so it was a bit odd compared to this wiring above but it's all good. Freezing cold AC is back!