Maxxair 4500K RV roof fan only works on intake, does not exhaust

[withalligators]

Hey folks,
I have a sprinter for field work. To keep it from getting roasting hot by 6am, I have a Maxxair RV fan installed high on the rear door to both exhaust (say if I'm cooking) or intake cooler from air from outside. It became functionally intermittent and just in the last few days has ceased exhausting. The motor sees no power when it should be exhausting, which leaves the control board as the culprit. Rather than simply replace the entire board which is a bit exhorbitant for what it is, I am wondering if there is a particular component likely to be at fault that you smart folks might identify.

If I had to guess, I would say the big HK14FD relay has probably failed.

[stj]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

"ROSH compliant" ??
ba haha.
thats supposed to be "RoHS" removal of hazardous substances.

it does look like the relay flips the polarity, but check if it's actually getting power to the coil before condeming it

[diif]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

"ROSH compliant" ??
ba haha.
thats supposed to be "RoHS" removal of hazardous substances.

it does look like the relay flips the polarity, but check if it's actually getting power to the coil before condeming it

No it's not. RoSH is Restriction of Hazardous Substances.

[stj]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

keep trying, re-read your post

[redwire]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

"ROSH compliant" ??

No it's supposed to read "ROSH COMPLAINT" hahahaa Xi is going to punish that guy

OP, the IR remote receiver modules I have seen also go bad. Also check if the remote is the problem. A flaky relay can be flushed out by gently tapping them when on.

[CapLeaker]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

Either the relay failed, the relay coil failed, or the relay isn’t getting energized.

[R_J]

Re: Maxxair 4500K RV roof fan only works on intake, does not exhaust

Does the fan work on intake? if it does, can you vary the speed? If used, does the lift motor operate and open the vent cover? or is this just manual cover opening? Have you checked the (poly) fuse on the board?