Community Forums

davismills · 02-13-2016, 05:34 AM

I have a Mor Aid rear heater in my Winnebago 2011 Sightseer 33C. Recently, I noticed that the rocker switch lights were not illuminated, nor would the fan operate. Traced to a bad fuse, replaced and the fan then worked in both low and high speeds.

I went down to the storage facility and started the motor home and discovered that the fuse had blown again. Keep in mind, that the unit is winterized and the water heater is in bypass.

I had no time for troubleshooting at that time, so will return for more troubleshooting later. When I replace the fuse and the fan works (temporarily) there appears to be no binding noises at all. I've searched all the threads on this subject and nothing seems to address this issue directly. There appeared to be one helpful thread, but all the pictures had been deleted.

Advice welcome. Love this forum and all the helpful folks.

ChasA · 02-13-2016, 08:55 AM

It's called Motor aid, not Mor aid.
First, verify that the fuse is the correct size.
If it is, I suggest you put an ammeter in the circuit and measure the amperage the fan motor is drawing. Do this first at the motor. If the amperage is less than the fuse rating, repeat the test at the switch. If you get a higher reading here, you've got a short in the wiring somewhere between the switch and the fan motor.

davismills · 02-13-2016, 11:25 AM

Quote:

Originally Posted by ChasA

It's called Motor aid, not Mor aid.
First, verify that the fuse is the correct size.
If it is, I suggest you put an ammeter in the circuit and measure the amperage the fan motor is drawing. Do this first at the motor. If the amperage is less than the fuse rating, repeat the test at the switch. If you get a higher reading here, you've got a short in the wiring somewhere between the switch and the fan motor.

Thanks! I will proceed with this great advice soonest. I did verify the fuse as this is the second time I've replaced it. 10 amp.

alank · 02-14-2016, 06:39 PM

I you can get to it, spin the fan with your finger to see if it spins freely. If it drags, it may run but burn the fuse after it runs a while because it's drawing too much current.

cbeierl · 02-14-2016, 06:45 PM

My understanding is that a number of folks with older vehicles have had problems with the fan sticking and blowing the fuse. I would recommend getting access to the fan to check it out.

Ray,IN · 02-16-2016, 09:55 PM

Rent, borrow, or buy an AC/DC inductive ammeter and determine ampere draw of the unit while running. It clamps around pos. wire and reads current draw/flow through the circuit. It may be left in-place to constantly measure current draw from start-up to when the fuse blows.

davismills · 03-06-2016, 07:40 AM

I keep blowing 10 amp fuses with this problem and looked up the voltage for the fan and lo and behold it's a 15 amp switch/fan. I really don't know why the factory put in a 10 amp fuse. Shoot me down if my reasoning is wrong. Definitely not an electrician. Nothing else appear to be wired to the same fuse.

davismills · 03-06-2016, 07:43 AM

Here's a link to the switch. 15 Amp switch

Clay L · 03-07-2016, 02:36 PM

It's a known issue. The motor seizes up because the fan shifts to one end and binds. Mine did it at about 6 years.
On mine there were three other items connected to the same fuse including the auto step retraction signal lead and the backup monitor. Removing it was going to be a major pain because it was located way back against the wall and the water heater would have to be removed to access it. I had used it maybe twice in the six years since I bought the motor home in 2004 so pulled the dash switch out (it is just snapped into the dash and comes out easily) and unplugged the connector and put the switch back in place. I did that so I wouldn't inadvertently turn the fan on and blow the fuse again.