Awning motor blowing fuse.

[rpaling]

Hello everyone, I have a 2016 Reflections 332RLS fifth wheel trailer. The awning on the dinette slide out blows a fuse when I try to extend it. It worked fine when I put it away last winter, but blew a fuse the first time I tried it this year. I've replace the fuse a couple of times and its a hard blown fuse every time. Any suggestions on how to troubleshoot this problem would be appreciated.

Thanks

Ralph

[TedS]

Does the motor run before the fuse blows?

[howson]

rpaling -- have you checked continuity (with a multimeter) from the fuse holder to a known good ground (or 12v return, to be more specific)? I'm guessing you'll find there's little to no resistance, thus indicating somewhere on the wiring it's frayed, pinched, or otherwise has an issue.

[rpaling]

The motor does not run at all. When I replaced the fuse and pushed the extend button, the fuse immediately blew. I have not checked any of the wiring yet with a multimeter. Not sure where to start.

[Scott'n'Wendy]

I have not had to work on an awning yet, imo, the first step would be to disconnect the wiring at the motor, cap the wires on the line side and replace the fuse. If it blows, you have a shorted wire. If it doesn't, you have a motor problem. be it a shorted motor, or jammed motor. If the awning is somehow jammed, the fuse would blow without you being able to detect if the motor tried to run.

[howson]

rpaling -- Scott'n'Wendy 's input is an excellent starting point.

Assuming the awning is tucked up against the camper you'll have to manually extend it (consult the owner's manual for your specific model of awning). Once extended on the motor side (typically on the side closest to the front of the camper) there's a channel covered by a panel that hides the wiring. When that panel is removed if it's like my Dometic awning there's an SAE connector that makes it easy to disconnect the motor and then do the test Scott suggests.

If this is still confusing post the specific model of awning and we can attempt to provide more specifics.

Howard

[rpaling]

So the awning is a Dometic 9100. The awning is rolled up tight against the trailer. I undid the two allen key screws on the right hand side and was able to manually extend the awning a couple of inches. Enough to disconnect the power to the motor. With the motor disconnected, I replaced the fuse. The lights in the slide out now work fine. However, when I press the awning extend button it immediately blows the fuse. This would lead me to believe that there is a short between the awning exstend button and the motor terminals. im not sure how I'm going to troubleshoot that wiring as its mostly covered.

[howson]

So the awning is a Dometic 9100. The awning is rolled up tight against the trailer. I undid the two allen key screws on the right hand side and was able to manually extend the awning a couple of inches. Enough to disconnect the power to the motor. With the motor disconnected, I replaced the fuse. The lights in the slide out now work fine. However, when I press the awning extend button it immediately blows the fuse. This would lead me to believe that there is a short between the awning exstend button and the motor terminals. im not sure how I'm going to troubleshoot that wiring as its mostly covered.

Most likely the failure is at a pinch point somewhere in the awning's wiring. There's a gob of sealant where the wires enter the trailer's wall. Carefully dig out that sealant and you'll find where the wires for the awning are tied into the camper's wiring. (You'll also see the wires for the lights.) Similar to what I found on mine (pic below):



Separate the awning wiring. Using a multimeter set to check continuity (ohms) look for a short on the awning side and then on the camper side between the hot wire and return wire. (NO POWER applied when doing a continuity check!) With the awning motor disconnected the awning wire should be "open" (infinite resistance) between the two awning wires. There should also be infinite resistance on the trailer side (switch NOT engaged) between the hot and return. Most likely you'll find one of those wire sets have a "short" (no resistance) between the two wires, thus the fuse blows when power is applied.

Again--NO POWER when doing a continuity check with a multimeter. (Sorry for being repetitive...you could be an electrical engineer for all I know...but just in case I default to being cautious...)

Howard

[rpaling]

Here's an update on my journey to get the awning working again. I've tested the motor by disconnecting the input power cables and hooking up an external 12v battery. The motor works fine, both extending and retracting. I've removed the switch and checked the continuity of the switch. It appears to be fine as well. Still blowing a fuse when I press the extend toggle. The fuse does not blow when I press the retract toggle. Based upon that am I correct in assuming that I have a bad switch. If it was in the wiring, wouldn't it blow a fuse in both Ext and Ret? Would love to hear some opinions.

[Country Campers]

Here's an update on my journey to get the awning working again. I've tested the motor by disconnecting the input power cables and hooking up an external 12v battery. The motor works fine, both extending and retracting. I've removed the switch and checked the continuity of the switch. It appears to be fine as well. Still blowing a fuse when I press the extend toggle. The fuse does not blow when I press the retract toggle. Based upon that am I correct in assuming that I have a bad switch. If it was in the wiring, wouldn't it blow a fuse in both Ext and Ret? Would love to hear some opinions.

Switch the wires on the back of the switch, swap the extend and retract ones, if the fuse blowing moves it is in the wire, if it stays the same then probably the switch.

Brian

[Lonestar]

Does the awning manual state specifically the rating of the fuse needed? Is there a remote possibility that by mistake a fuse of smaller than needed current rating was used in the awning circuit? Even so, it doesn't seem it would trip only in one direction.

[howson]

rpaling and Lonestar

Below is what I think is happening. The awning motor reverses direction by the switch swapping + and - 12vDC. Note how in one direction when +12vDC is applied if the wire is shorted the fuse will blow, but when the switch reverses the "shorted" wire is now just another path to frame ground (which the motor needs to work).

[carrtommy]

Howson has some excellent information. When you tested the motor, you tested it with a floating 12vdc power supply. If the negative side of the 12vdc was also connected to a ground on the RV, then test it, it would confirm that the motor is good. I would also disconnect the motor where you previously tested it. With the disconnected wires coming from the switch, and the power restored to the switch, test the wiring unto the disconnected point and determine if the ground is before or after the disconnected point. i.e. if the fuse blows, the problem is in the wiring going back to the switch. When you previously tested with a floating 12vdc power supply, it did not confirm that a ground in the wiring to the motor did not exist. By grounding the negative side of the 12vdc power supply to the chassis of the RV and doing the test again will confirm whether the problem is from where the 12vdc power supply was connected to the motor is good or not. I have over 30 years in Nuclear power as an I&C Engineer solving electrical issues.

[Ray&KatinCR]

To eliminate the possibility of a bad switch I would disconnect both the motor and the switch then check for continuity to ground on BOTH wires. If one wire shows o ohms to ground that is the bad one. If both wires show infinite to ground then it has to be a bad switch.
If it's a bad wire Like Howson said, start with the pinch points first. chances are that's where your problem is. Wires do not just inadvertently short out without help.
If it's the switch, easy peasy just replace it.

[rpaling]

Folks. I figured out what was wrong. There was a short between the motor and where the wiring went into the wall of the slide out. Simple fix, I replaced all the wiring that went through the swing arm and its worked perfectly every since. Thanks for all the advise from everyone. This forum is great.
Cheers