# wiper motor getting hot



## gooffy87 (Oct 18, 2011)

Hello all,

I have been toying around with wiper motors for a while, my question is, why does the wiper motor get so hot? even if it is not under any load. I am running it with a 12v 6 a power supply. Is it because it is running so fast? Would resistors help keep the temperature down? btw, it is running in a continuous non-stop fashion and it is used, probably about 10 years old at least. thanks!

also, I have been looking into buying a few from monsterguts, would there be a difference between theirs and the old ones found on eBay? thanks


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## gooffy87 (Oct 18, 2011)

btw, i am running it on the low speed terminal


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## Otaku (Dec 3, 2004)

When you say "hot", do you mean too hot to touch? If so, that's not good. Sounds like you have a short in one of the field coils causing it to overheat. I've had this happen with other motors before - the motor runs, but gets very hot even with no load on it. Your power supply is fine, the motor will draw only as much currrent as it needs. Do all of your motors do this, or is it just a particular one?


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## gooffy87 (Oct 18, 2011)

just this particular one, do you think this is fairly common with old motors? im gonna start buying monsterguts motors, they are probably more reliable


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## Otaku (Dec 3, 2004)

Old motors are probably more prone to this type of failure. I agree with you on the MG motors - I have several and never had a problem with them.


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## gooffy87 (Oct 18, 2011)

sounds good, thanks as always otaku!


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## Otaku (Dec 3, 2004)

Forgot to ask, are you using a regulated power supply? An unregulated 12VDC wart can put out 16-20VDC depending on the current draw.


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## gooffy87 (Oct 18, 2011)

It is regulated, it does not have a volt range printed on the power pack, it just says 12V. Just out of curiosity, what would an unregulated pack do to the motor?


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## Otaku (Dec 3, 2004)

Unregulated warts are usually going to deliver more voltage than the label says. They only get close to the rated voltage when the rated amperage load is applied. Example - an unregulated wart rated for 12VDC at 1A will only get close to that voltage when you have a 1A load on it. If your amperage load is higher than 1A, you get a drop in the voltage and the wart starts to get warm.
Since most car batteries deliver a little more than 12VDC, you'll probably just see the motor spin faster until you get some weight on it. I have used a 9VDC 1.5A wart with a wiper motor that measured 16VDC unloaded. The motor has seen many hours of use with no problems.


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## gooffy87 (Oct 18, 2011)

interesting, thanks for the info!


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## Thisaintmayberry (Aug 23, 2010)

I would try switching to a known regulated power supply like an ATX if you have one, before you dump the motor. Also, if it is a really old motor, your gear set could be binding up if there is a lack of lube or debris inside the housing.


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