Discussion:
EV-1 no scr hum

Ok, I've been working on an old Clark M: EC500-120 SN: E912-0008-6380. Unit has an Ev1 with extra large #1REC, #5REC etc. When you travel the contactors pull in but No scr hum and no travel. I have removed and tested the #1,#2,#5 RECs with a 12 volt battery and they will switch on and remain on until circuit is opened. I think they are good. I've tested #3,4 RECs (diodes) with a fluke meter and they conduct in one direction only. Resistance test are showing 750k ohms from componets to chassis. Isolated Battery by lifting and placing a sheet of plywood between battery and chassis Becouse I've heard of chassis voltages and some strange affects they can have. Have tested and inspected current sensor and all conections are good. Have raised drive tires put directional switch into fwd so fwd contactors close and then manually closed 1A contactor-drive wheels turn with 1A closed which tells me brushes etc. are good. Tested all Caps -good.
One thing that I have noticed is there is no cable or wire on T2.
Thanks ahead for any help anyone can give me.
  • Posted 7 Aug 2010 07:33
  • By rrlift
  • joined 27 Feb'09 - 22 messages
  • Illinois, United States
Working so I can ride.

Post your Reply

Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.

If you are having trouble using the Discussion Forums, please contact us for help.

SMV (Konecranes) 16-1200C
Balling, Denmark
Used - Sale
UN Forklift FBRS15KQZ2
HANGZHOU, Zhejiang, China
New - Sale
Latest job alerts …
Uxbridge, Canada
Evansville, IN, United States
St. Louis, MO, United States
Daleville, IN, United States
Movers & Shakers
Jeannette Walker Jeannette Walker
CEO, MHEDA
President, European Rental Association (ERA)
Chief marketing officer, JLT Mobile Computers
Chief executive officer, East Penn Manufacturing
Global Industry News
edition #1236 - 26 June 2025
As June comes to a close, the month when our sector recognises National Forklift Safety Day , the United Kingdom’s Association of Industrial Truck Trainers (AITT) has issued a timely reminder of the need to ensure any staff training is fully accredited... Continue reading
Crown Equipment celebrates 80 years New Bremen, OH, United States
Upcoming industry events …
July 9-10, 2025 - Birmingham, United Kingdom
October 21-23, 2025 - Panama City, Panama
Fact of the week
Sourdough bread contains Lactobacillus reuteri, a probiotic bacteria. During pregnancy and breastfeeding, these bacteria can travel from the mother's colon to her breast tissue and be passed to the infant through breast milk. It offers various health benefits, including potential protection against breast cancer.