Boosting power on power windows

Thread Starter


Joined Jan 29, 2016
I work in a shop that restores old cars and after replacing window seals on power windows the motors often
struggle to raise the window against the added friction of the aftermarket seals.
I was thinking of using a boost converter like this one: Boost Converter
to boost the voltage to around 16-18 volts.

Would this solve my problem and would this unit do the job?
the motors currently avg. 10-15 amp stall current measured with a clamp meter.
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Joined Dec 2, 2013
no, you have to solve the mechanical problem the motor was designed to do the job. When it does not then the motor is defect or you face a mechanical problem. boosting is forcing it to go is not good practice for a professional.


Joined Aug 21, 2008
I tend to agree with Picbuster, but your question was whether or not the subject power supply would work in your application.

Since your motor would take 10 to 15 amps and the power supply's maximum current is 10 amps, I would not put that power supply into that application -if you were lucky, it would be marginal at best as far as the current rating is concerned.

Other things to consider are that the subject power supply was probably designed for an commercial or industrial temperature range, rather than a much more sever automotive temperature range. That heatsink suggests that there also be an unpublished airflow requirement. Susceptibility to damage from vibration is also something to be aware of.

Thread Starter


Joined Jan 29, 2016
I certainly agree but in the 20 yrs. that I have wrestled with this issue there are only 4 outcomes.
1. wait yrs. for the aftermarket seals to wear in.
2. spend weeks messaging the parts and still rarely achieve acceptable results.
3. find 50+ yr old original seals - very rare.
4. there is 1 company that makes power window regulators with more powerful modern motors unfortunately they only make them for a few models.

I believe the motors were barely adequate even when new and that this is one reason why power windows were not as popular back then even on the upscale models.
Also people today expect quality standards to match what has been achieved in modern cars and forget that it just wasn't at that level when these cars were first built.

@ DickCappels
You're right, I dropped the ball hard on that one.


Joined Sep 30, 2009
Have you tried a rubber lube in the seal groove? The only thing is I wouldn't use the lube untill after any paint work is done. Many/most of the rubber lubes contain silicone, if used before paint you risk "fisheyes" in the paint. Don't ask how I know.:)


Joined Mar 14, 2008
The problem with raising the voltage to the motor is that the motor magnetics may saturate and draw a very high current, burning out the motor.
Motors generally don't tolerate a voltage much above their rated very well.

I also think lubing the various sliding parts would be the preferred solution, if you haven't tried that already.

Thread Starter


Joined Jan 29, 2016
I've tried every type of lube I can imagine over the yrs. even tried polishing the regulator tracks once, anything to reduce friction.
While that can help, I have not yet found a method that produces acceptable results.

Since I have found no support for this idea at all, I will likely forget this one.
At least until the next insistent customer forces me to try it out of sheer desperation.:mad:

Thanks for the advice,


Joined Aug 30, 2007
Would it be feasible to change the gear on the motor to give you a different ratio ?
The window would raise slower, but it would work..


Joined Sep 30, 2009
Hutkikz, aren't you using window fuzzy tracks? Most of the old cars used them instead of rubber seals. Are you rebuilding the bushings in the regulator pivots?

Thread Starter


Joined Jan 29, 2016
The all fuzzy one's never have a problem. but by the early sixties most cars had rubber for the critical sealing surface's.
The regulators are not easily rebuilt by a small shop like ours, we exchange with a shop that rebuilds them.
the motors are rebuilt originals also. they are flattened so as to fit the space, I don't know of a a modern equivalent that would fit.
the one company that uses modern motors only makes them for cars that can fit the fatter motor's.

The real problem with the aftermarket seals is that they are solid foam rubber with a channel molded into them.
the original's were real rubber that had a flap that pressed against the glass.
The foam rubber exerts much more pressure on the glass than the original's.

Silicone spray is about the best lubricant I've found also, and it doesn't streak the glass.
but it is not enough to overcome the added friction of the foam rubber. This is the change that has upset the balance of the system.

With the unavoidable added resistance it seem's to me that more power is the only solution here.
I talked to a racer friend today. He has a 16v battery that he will let me borrow to test with,
so if I don't smoke the motor during testing I may still give this a try.

That might work,but I don't know if it's possible.
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Joined Sep 30, 2009
Could you show or link to the type of regulator and motor your talking about? As a long time old car junkie I've built and repurposed many things in my time on earth.

Do you have any scraps of the seals your using? For experimenting. Most of that foam stuff is thermoplastic. So maybe it could be "reformed" by using a piece of aluminum flat stock of the correct thickness and a heat gun. Or if not, you could shave a slight amount off of the back side of the seal before gluing in place to open the window track area so it will slide easier.
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Joined Oct 8, 2011
I believe the motors were barely adequate even when new
I have successfully used old wiper motors in this situation as they have lots of torque. It depends on the space available and you will have to do some machining.
It is also worth checking that you don't have a whole load of voltage drop going to the motors, check the voltage at the motors, under load and fix if necessary. Remember power output is proportional to voltage squared

Thread Starter


Joined Jan 29, 2016
Today I was able to test with my friends 16 volt battery and it worked beautifully.:)

I also talked to the manufacturer of the 16v system my friend uses, and the company that refurbishes the power window regulators we use.
In both cases they claimed there should be no issue and it won't void the warranty of the regulator, which surprised me since I had major doubt's after posting here.

These 16v systems(battery/alternator) are designed primarily to provide hotter ignition and more powerful cranking for high compression motors. Since this isn't a concern for my situation I don't feel that I should subject the entire system to the added stress (and cost) for just the windows. I also learned that I could get the current capacity needed by running 2 boost converters in parallel.

Since no one here is trying to sell me anything(warranty is only 90 days) I wanted to bring this up again and also ask which method would be best.


Joined Jul 1, 2009
It won't harm the motor at all. If the resistance had not changed it might, but resistance has changed. That increased R (or impedance in this case) will soak up the extra I created by the higher E. It's actually easier on the motor, because it will run at a speed closer to what it was designed for, thus increasing reactance, and it will run for a shorter period than if it struggles.

blocco a spirale

Joined Jun 18, 2008
I agree with Post#14; check the voltage at the motors.Old switches and connectors could have significant resistance. It may be possible to fix this using relays and larger cables with a feed directly off the battery.


Joined Jun 26, 2012
Have you measured the voltage at the motor terminals when its running? If it's low due to the current draw, bigger wire in the entire circuit might help.