i am workin on a 2020 ic with psi motor when ever i turn the ac on the voltage drops fast i tried using only on ac and it drops slow if i use both it drops fast it vurned up an alternator i checked all grounds and powers cleaned all connections still no change i started eliminating blowers and condensor fans everytime i do that it just slows the drop but still loses voltage i ran a new man power from ac boards to battery no change any ideas
I have a 2024 with AC that had some gremlins. The dealer ended up re-grounding the entire rear system to the body rather than having to grounded all the way to the front of the bus as it came from the factory. Zero issues since.
ok i will try that but it drops a little when i usse just the front or rar if i turn all the switches on without the ac on it drops a little but i noticed when its cold and u turn both ac on no drop when engine warms up then it starts to drop
what voltage is your bus running with nothing on this one is at 14 i have a sister bus that runs 14.5 and whhen i turn both ac on it goes to 14 so i am wodering if its not the ac its something else
at idle with everything of i have meter right at back of alternator i got 14.2 volts on the scanner it only shows 13.5 with ac on the meter on alternator shows 13.9 0n the scanner it shows 12.9 any ideas?
we do not run a/c on the busses up here, but this scanner is it giving you the voltage that a module is seeing , does this wire only supply this module , if you have Jpro what does the voltage for other modules(abs,Ecm,esc, allison) show the same or different, if different i would look at that power wire, the ground for that module or the module itself , this is all guessing Ive never seen a/c on a school bus
OEM trained in wiring and all engine platforms for over 20 years
its showing that at ecm have to check on abs module and tans module all our buses have ac some have three units three compressors this one only has to and it melted the alternator when both where rynning
2020 ic voltage drop
Posted - 07/02/2024 : 05:56:06 AM
