Discussion:
Electrical short

Pops the 15 amp main power relay, ECU, 02 Sensor as soon as key turns on.
Here is the what I have dones. Checked and cleaned grounds and battery terminals. Checked harness for short to power or ground. Isolated it to the MPR1 relay circut. Pull mpr1 relay put in fuse pull up codes. 711 LSD_1 dither 1 open or short to ground blaa blaa. What and where is a dither?
431 EST1 open or shorted to power or ground or bad spark module. Again what and where is EST1?
Have color schematic and mpr1 is green n white for 02 sensor. Red battery, red n white x2. 1 red n white goes to ECU power, other red n white goes to optional connector. I still have to find the opt connector, if used and what it feeds.
Any thoughts?
  • Posted 16 May 2018 10:57
  • By Shadetree5080
  • joined 16 May'18 - 4 messages
  • Nevada, United States
Shade
Showing items 1 - 1 of 1 results.
Dither valves or also called FTV (fuel trim valve). can be found behind the vaporizer two black valves with vac lines and wiring attached. LSD refers to the style of Delco ignition system used. Check for shorts to and from the distributor, coil ect. Check also the harness which crossed over the transmission. Often this harness will wear through and short to trans.
  • Posted 18 May 2018 07:07
  • By tom_p
  • joined 21 Feb'11 - 198 messages
  • Alberta, Canada

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) 33-1200C
Balling, Denmark
Used - Sale
Maxlion FD25
Hangzhou, China
New - Sale
Upcoming industry events …
January 28-30, 2026 - Bangkok, Thailand
March 4-5, 2026 - Detroit, Michigan, United States
March 24-26, 2026 - Stuttgart, Germany
Latest job alerts …
Erie, PA, United States
Dayton, OH, United States
Movers & Shakers
Jett Chitanand Jett Chitanand
President EPG Americas, Ehrhardt Partner Group (EPG)
CEO, Duravant
Manager of automated solutions engineering and implementation, MHS Lift
President and CEO, Manitou Group
Latest job alerts …
Erie, PA, United States
Dayton, OH, United States
SMV (Konecranes) 33-1200C
Balling, Denmark
Used - Sale
Maxlion FD25
Hangzhou, China
New - Sale
Upcoming industry events …
January 28-30, 2026 - Bangkok, Thailand
March 4-5, 2026 - Detroit, Michigan, United States
March 24-26, 2026 - Stuttgart, Germany
Editorial calendar - planned features
CONSTRUCTION FORKLIFTS
HANDLING GOODS IN THE COLD
LOADING/UNLOADING FREIGHT
BROWNFIELD AUTOMATION
FORKLIFT ATTACHMENTS
BATTERY AFFORDABILITY AND LIFETIME
FORKLIFT SAFETY
SMV (Konecranes) 33-1200C
Balling, Denmark
Used - Sale
Maxlion FD25
Hangzhou, China
New - Sale

PREMIUM business

Ningbo Ruyi Joint Stock Co., Ltd.
Manufacturer of forklifts, power stackers & pallet trucks.
Global Industry News
edition #1260 - 11 December 2025
In this week’s Forkliftaction News we report on DHL Supply Chain signing a deal to deploy autonomous mobile robots (AMRs) at its Mexican retail operations and look at Guidance Automation’s successful trial of an AMR with a hydrogen fuel cell... Continue reading