JD LT155 SN072651 wiring problem

Reply

  #1  
Old 04-17-07, 05:01 PM
Member
Thread Starter
Join Date: Dec 2006
Location: south carolina usa
Posts: 180
JD LT155 SN072651 wiring problem

ding mower w/o elec PTO and electronic control board, has four Bosch type relays in control circuits. The only wiring info I can find is on the JD site which shows wiring harness only. Need wiring or schematic diagram to trouble shoot starting problem. Found one in line diode that did not read good and jumped out , problem solved. Almost!!!Got a new diode from JD store and put in line, same problem. Put jumper in again, all works well. With a schematic, I could determine if the diode was an essential devise and if not could be jumped out. Oh for the lack of a diagram. Tom
 
Sponsored Links
  #2  
Old 04-17-07, 08:55 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
I don't know where to find a diagram, especially for a PC board like that. I would suspect that there wouldn't be a diode there if it wasn't needed. It just blew the new diode? Did you install one with the proper amperage rating? Even if it wasn't essential to have a diode there, the fact that it's burning up is indicative of another problem. Patching it with a jumper would just be a bandaid, not a repair of the actual problem.
 
  #3  
Old 04-18-07, 12:28 PM
Member
Thread Starter
Join Date: Dec 2006
Location: south carolina usa
Posts: 180
It was never my intention to leave the jumper in place of the diode, that was placed there only to test the starting circuit. You are right, the diode is there for some blocking purpose. The diode is not bad, and is a Deere part as well as the new one tried in its place. This mower is probably an HD or Lowes sold unit and does not have the PC board, but does have four Bosch relays.
We have solved some of the problem, but could still use a schematic to check out and service the rest of the circuitry. I really appreciate your reply and still hope that you can come up with a schematic source.
This particular mower was left at another repair shop for one year, according to the owner, and finally returned to him with, I'm sorry we just can't fix it.
Always good to hear from "Cheese" God Bless Tom
 
  #4  
Old 04-19-07, 10:36 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
It was at a repair shop for a year and returned un-repaired!!?? Sheesh. What exactly is it doing? Have you verified that all the relays are working properly? Not just clicking, but making proper contacts when on and off? I believe these relays close some connections and open others when on, and close some and open others when off as well.

Seems like moisture likes to get in those relay housings and corrode the contact points. Especially on mowers that people wash often, or that stay outside.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes