Wiper motor bad.Dumb Mistake Help

[Scorn]

I have a 2012 Winnebago Via and went to jump it and the wipers started acting crazy. No stopping even when turned off. Took cables off came back later tried to jump start again and the engine started fine. Went back again and it started fine.

Problem is, no power to the wipers at all. I did Smell smoke when I first tried to jump it. I may have placed the ground to close to the brace and fried the motor. I found a new motor at Geek parts for $90.

How can I be sure that's the problem?

[Winterbagoal]

Fuses? Relay? Probably fried at least a wire or two.
Didi you use the battery boost switch? Does it have one?

[Morich]

I would want to test for voltage actually getting to the motor and then check the linkage for free movement before removing the motor and testing it . A burned out motor will get LOTS of smoke and lots of smell but something else burning out like shorted wire, etc. may make a smell but not as much. Reason for needing to jump start? Possible wire to the motor shorted to ground, killing battery but when jumped, it went ahead and burned all the way? Just some guesses as motors are pretty tough to burn up and wires, not so tough?
Note that things like chipmunks or whatever local rodent is around can chew wiring while we have rV stored.

[Scorn]

It does not have a battery boost switch, it has a positive short rod like terminal that you push back and then connect the positive clamp from the jumper cable to jump it.

i jump it before last yr and then bought a new battery. This time Ii placed the ground in the same place on the plate that is close to the brace for the arms where the wipers are. I think I got it too close this time.

[Scorn]

What motor are you talking about the wiper motor? I did get some smoke and the wipers were acting crazy, I couldn't turn them inside. Now they won't even move.

[Morich]

I was talking about the wiper motor as you mentioned changing it, but reading over the first post, I really doubt the wiper motor is bad as it did keep wiping after the first jump, correct?
What I think will be found is that there is some smaller part like a relay or wire that has burned.
The problem we have is we can get good drawings that are a big help for the AC power and the DC that feeds the coach items like the water pump, inside lights and frig as those are Winnebago things and they do a pretty good job of putting those drawings online here:
Wiring Diagrams
But when we need to look at things that are part of the vehicle build like wipers, headlights or horn, Those drawings are hard to get from the folks like Ford, MB or Chevy. Sometimes it is possible to find a repair manual that is close to what we have but not RV and we have to do lots more guessing or take it to the dealer!
So life gets harder and we have to do more hunt and peck checking for what is "normal" rather than actually tracing wires on a diagram which show it goes from here to there. I don't know M-B chassis at all but many cars do not use a wire to run ground to the wiper motors as the total frame of the car is ground and the bolts holding the motor on the frame are the ground. They take a hot battery wire from a breaker or fuse panel to the motor. Sometimes it runs through a relay, so checking the fuse/breaker panel for a problem there is first if the wires are hard to find, but the real way to check the wiper motor is to see that it does turn by hand and then connect 12v battery to the wire and see if it spins. So if it spins when connected directly to battery, we have to go back along the wire to find a relay or why power is not getting to the motor from the fuse or breaker.

[Scorn]

Morich, Thanks so much for your help, I really appreciate it. No, they didn’t” do anything after the first jump. The engine started fine after the second jump, but the wipers will not do anything even turning them on with the column. I’m sorry if I wasn’t clear.

[Morich]

Okay, no problem I often find this communications thing is harder than it seems!
I would still have to do some looking at the power before going for a new wiper motor as it should have blown a breaker before it actually got down to burning out but then I'm going way into guessing without checking.
Maybe just my nature to not spend money until I really see it--even if it's your money!

[PartPlan]

Our 2015 Via's wiper motor whines loudly

[NeilV]

Yes check for blown fuses, burned wiper relay and burned wires/fuseable links first. Hopefully Mercedes stayed simple and does not have the wipers controlled by a computer and just has a time delay relay and other tried and true old school devices protecting the motor.


Accidentally shorting the wiper arms to positive should not have burned out the motor on a standard system. And shorting them to ground should have done nothing.

[Deny]

I'm sure you will get to the source of the problem by working your way through the components.

I have done worse..I fried an alternator doing what you did. The parts man told me:"when they build these electrical components, they put smoke inside them. If you let the smoke out, they don't work anymore" I never forgot....

[Wyatt]

This is from the Ford 2018 F Series manual. Maybe it is the motor? Easy enough to test by disconnecting it and applying 12v to it?