New MaxxAir fan works on Battery but not shore power..

[hscheper]

Hello you awesome people!
I have a 1985 Bigfoot 17G (Stock trailer) that has an electrical anomaly. I decided this year to install a new Maxxair powered fan and wire it into a near by roof light. Install went fine and the fan works great as long as I'm on battery only. As soon as I plug into shore power the fan stops. Put a multimeter on and I get about 12.5V on battery, but as soon as shore power is on it jumps to 13.6v. Manufacturer says I need to get this below 13.1 for the fan to work.

So... new power converter????


Thanks in advance for your advice!!!!

[Jon Vermilye]

Originally Posted by hscheper

Hello you awesome people!
I have a 1985 Bigfoot 17G (Stock trailer) that has an electrical anomaly. I decided this year to install a new Maxxair powered fan and wire it into a near by roof light. Install went fine and the fan works great as long as I'm on battery only. As soon as I plug into shore power the fan stops. Put a multimeter on and I get about 12.5V on battery, but as soon as shore power is on it jumps to 13.6v. Manufacturer says I need to get this below 13.1 for the fan to work.

So... new power converter????


Thanks in advance for your advice!!!!

If you get a converter that only puts out 13.1V, you will never get your battery fully charged. If you want to protect the fan, get a buck converter, wire it into the fan circuit & set the output for 13 volts. There is a many page thread on dealing with Maxx Fan voltages at the Escape forum.

[Dan Meyer]

Something is really weird here. 13.8 volts should be no big deal. If it was, everyone would be complaining. 13.8 or even 14.4 volts is standard 12 volt battery charging voltage.

Measure the voltage at the fan while on battery, and then plug the camper into shore power. Does the voltage change polarity?



--Dan Meyer

[Radar1]

That's surprising that they can't cope with normal charging currents, never realized that. I looked it up and this video shows someone that got a new board after a year and a half, but was told he needed to get a voltage regulator. He has an interesting power setup in his conversion van.

[gordon2]

Originally Posted by Dan Meyer

Something is really weird here. 13.8 volts should be no big deal. ..

Agreed... any R/V appliance should be able to tolerate at least 15 volts DC. I did not read the linked threads and postings but hope its not the case that that fan fails at such low voltage.

[WizWid]

Originally Posted by gordon2

Agreed... any R/V appliance should be able to tolerate at least 15 volts DC. I did not read the linked thread but hope its not the case that that fan fails at such low voltage.

It does.