Genie TZ-34/20 Towable Boom Lift - Hydraulic Motor Issue

[SSNJOHN]

Yep, know it is not a tractor. Friend of mine had this "stored" on a ranch, in a building/barn for about 5 years since it last ran. It is basically 24 VDC from 4 6VDC golf cart batteries running a Hydraulic unit to operate boom and leveling outriggers.

Mice, rats, etc had field day with some of the wiring. They also stored ~ 100 lbs of cotton seed in various places on the unit, but that is not the source of the problem. On the hydraulic unit, there were multiple wires chewed completely through, including the negative(black) cable going to the hydraulic motor. No apparent sign of anything shorting out, burn or melt.

Repaired the damaged wiring. Connected it back up to some good batteries and immediately discovered Hydraulic Motor has short or ZERO ohms between motor post for red wire and motor post for black. I am somewhat electrically cognizant, but no experience with hydraulics. The motor is just a DC motor, but I would not think the short condition would be good/normal. Can someone confirm this and/or possibly give me some guidance on next step, which I am assuming might be motor replacment.

I remember megging DC motors many years ago, but this was typically resulting in significant resistance between the motor armature and the case/ground.

SSNJOHN

 

[NormL]

Take that motor apart. With zero ohms resistance over the poles there is no juice getting through. Find the reason for that and try it out on the bench before putting it back. You may also want to make sure the hydraulic pump is not seized after sitting for five years. It shouldn't be but might as well make sure. Good luck!!

 

[SSNJOHN]

NormL,

Thanks for the advice. Looks like it is fairly simple to remove DC Motor and not mess with draining Hydraulic fluid. Will post up what I discover.

Regards,

John

 

[BeezFun]

Try rotating the motor slightly and take a few more resistance readings each time. If the readings fluctuate I'd suspect the brushes. You might be able to remove the brushes without taking the motor out. Once you get the brushes out, if they look to be in good shape, try to stick your probes into the opening for the brushes and see if you can directly touch the commutator ring. If you can get your probes directly on that ring and it still reads zero, that almost guarantees the winding is broken somewhere.
I resurrected a towable lift from an abusive home but it sounds like yours is in worse shape.