What To Check If Progressive Dynamics PD4645V Converter Fan Will Not Run

Updated 05/07/2026 | Published 05/02/2026

Question:

I installed a Progressive Dynamics 6345 recently and the cooling fans stopped running. Ill hear a slight humming but im getting no action from them. Is there a inline fuse for these or what can I do to troubleshoot?

asked by: Brody T

Expert Reply:

Hey Brody, thanks for reaching out. What you’re describing usually isn’t an inline fuse issue, those units don’t have a separate fuse just for the cooling fans. The fans are controlled off the converter board and only kick on when the unit gets warm enough or under load. That slight humming you’re hearing is likely the transformer, which tells you the converter is powered up, but the fans just aren’t being triggered or aren’t able to spin.

First thing I’d check is whether the converter is actually under load. If you’re plugged into shore power with a fully charged battery and not much 12V draw, the fans may not come on at all. Try turning on a bunch of 12V loads like lights, fans, etc. to see if they kick on. If they still don’t, pull the cover and make sure nothing is physically blocking the fan blades and that they spin freely by hand. At that point, if you’re getting heat and still no fan movement, you’re likely looking at either a failed fan motor or an issue with the fan control circuit on the board. That would be covered under warranty so if that turns out to be the case give us a call at 1-800-298-1517 and we can get the ball rolling on a warranty claim.

expert reply by: Jesse M

Progressive Dynamics Replacement Section for AC/DC Power Distribution Panel - 45 Amp
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Brody T.

5/5/2026

Ill have to play with it some more and see how much load and or heat it takes in order for them to kick on. On another note since installing the 6345, when traveling the truck is no longer charging the camper battery, atleast when the fridge is on. the battery separator seems to click once the fridge is turned on while connected to the vehicle and only taking power from the camper battery. Is this something the converter has to do with?

Jesse M.

5/6/2026

@BrodyT No that isn't the converter. The PD6345 only charges when you’re on shore power, it doesn’t play into the truck charging circuit while driving. What this usually comes down to is voltage drop or limited charge current from the truck. The factory charge line through the 7-way isn’t very strong, and once you add a load like a fridge, it can’t keep up. You’ll want to check voltage at the camper battery with the truck running and the fridge on, and also look at your ground and charge wiring for any weak points. A lot of guys end up running a heavier charge line or adding a DC-DC charger so the truck can actually keep the battery up under load instead of the separator dropping out.

Doug M.

5/6/2026

Like Jesse said, probably not enough load. I have the same unit in my MH, and seldom load it to the point the fans come on. Unplug the shore power and turn on enough DC load to draw the batteries down a good bit. Fans will probably come on when you plug it back in.