Correcting an error

In the video titled "testing a window motor" I made an incorrect statement at the very end. I guess my head and my mouth weren't on the same page that day. I thought about just deleting it, but then I realized it would make a great opportunity for a teaching point. After all, we all make mistakes. The important thing is to correct them. So, I hope this explains it better.

Category:

Autos & Vehicles

Tags:

• volts
• current
• resistance
• ohms
• amps
• voltage
• drop

[moparmuppet]

I just assumed that you were refering to the mechanical resistance of the motor (stiff bearing or whatever) not electrical resistance.

Great video as always Duane, Thanks so much.

[spelunkerd]

I noticed right away, and I guessed you would post a revision. I admire anybody who has the balls to admit a mistake, especially the way you did it here. Way to go, Duane, keep posting these videos.

[mejia1911]

higher mechanical resistance will cause a higher amperage draw right?

[AutoTechHector]

@thegameguy77 Reeelaaxxx....

[thegameguy77]

You clearly know more about mechanics than I will ever hope to, but I have a small disagreement with your corrected explanation. You said "If the current actually goes up and the voltage stays the same then the resistance has to go down" I think it would be more correct to say that the amps went up because the resistance went down if the voltage stayed the same. Resistance changes amperage, but amperage does not change resistance. Thanks for your excellent videos!

[dmorley100]

moparmuppet's right. I've actually observed what's he's referring to on both ends. The first, is the typical bad window motor like in the video. I've also seen the opposite of this as well in a Ford Explorer that had a mechanically bad fuel pump. This particular fuel pump had the seals that actually push the fuel failing under higher pressure, so it would run but not accelerate. The current dropped because the motor spun faster due to the decreased mechanical resistance from lower pressure.

[sbakar]

@kdknitro You can surely measure current using a measuring device called an ammeter. Use V = IR because it is standard notation for Ohm's law. 'Amps' is short for Amperes (A), which is the SI unit for current. 'Watts' (W) is the unit for Power, which for DC circuits is defined as P = VI.

[bhstone1]

V=IR is really the best equation to use. C isn't used much, but I means amps.

[Moosepiesandwich]

There's more than one lesson here, one on current versus resistance and one on how to be an Educator. Great examples of simplification, restatement and correction. Thumbs up!

[kdknitro]

you can also use v a r volts amps resistance rather than current you cant measure current you have to turn current into somthing wether it be amps or watts

[michaelovitch]

like mopar muppet said

i thought too that you were speaking about the mechanical resistance.

so to produce the same job the motor needed more amps because of the fact he had more mechanical resistance.