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Ridgid WD18500 shop vac

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  • Ridgid WD18500 shop vac

    I bought a WD18500 shop vac last summer, light duty, little use. While vacuuming sawdust, just quit. 90 day warranty at Home Depot, can't find receipt. Fix it myself rather than shipping back to St.Louis. Switch good, continuity to motor, ohmed windings, 1 side good, 1 side (w/ capacitor) not so good (resistance). Can't read printing on capacitor, white on one end. Looking for cap rating, where to find one.

  • #2
    Re: Ridgid WD18500 shop vac

    Here you go ->

    I don't see a capacitor but maybe you could give them a shout... ?

    "To order parts or accessories for this product, please contact us at 1-800-4-RIDGID."

    Last edited by jbergstrom; 03-15-2009, 08:22 PM.
    Cheers! - Jim
    All truth passes through three stages: First it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident. - Schopenhauer


    • #3
      Re: Ridgid WD18500 shop vac

      Try your Ohmmeter set to the R x 10 or R x 1 range. Connect this to the leads coming directly out of the motor. You should have low resistance when the brushes are in full contact with the commutator bars and higher resistance at times. The pointer should bounce as you slowly turn it.

      Note: You'll need a meter like a Simpson 160, 260, 270 or Triplett 60, 310, 630 (It can be a junky one for this.) and not a digital type for this test. .

      As for there being a capacitor, are you sure that's what it is? The only time I have ever seen a capacitor and there was two of them was back in WW2 days when they used them for radio noise suppression, but they also were dangerous to have installed. If the vac wasn't well grounded or if one of the capacitors shorted out, you got ZAPPED bad.

      Using the same type of meter if it is a capacitor you can sort of check it.
      A) Short out the capacitor for about 15 seconds.
      B) With VOM set to highest resistance range connect the leads to the capacitor. The pointer should move and then go back towards infinity.
      C) Reverse the leads or flip the + / - switch. Now it should move to low scale and then work back up towards infinity.

      There is no way you can have an electrolytic starting capacitor with that type of motor. I would expect if there even is a capacitor that it would be about 0.001 MFD and 600 Volts or higher.

      Final note: Before you go apeus, try removing the carbon brushes and note exactly how they were installed. Then blow out the brush holders gently with compressed air and a squeeze blower or canned air works for this. Then reinstall the brushes and see if it doesn't run fine again.