B7500 won't start. Glow plug key position seems incorrect

england006

New member

Equipment
b7500
Jun 11, 2021
11
0
1
ohio
Whenever I attempt to start I alway leave in the glow plug key switch position for a few seconds before engaging the starter. Normally in the glow plug position there is an yellow light that comes on. Today it won't start. The glow plug light only flickers on for a second but then goes off and seems to drain all power from the other starter lights. Never allowed to even engage starter after that. Battery is good. could it be the glow plug relay or controller? any ideas???
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,249
1,030
113
Williamstown Ontario Canada
Whenever I attempt to start I alway leave in the glow plug key switch position for a few seconds before engaging the starter. Normally in the glow plug position there is an yellow light that comes on. Today it won't start. The glow plug light only flickers on for a second but then goes off and seems to drain all power from the other starter lights. Never allowed to even engage starter after that. Battery is good. could it be the glow plug relay or controller? any ideas???
More likely you have bad battery connections. Do you have repair ends on the battery cables like this one.



battery cable repair end.jpg


Remove the ground cable where it attached to the frame or engine block and clean.

Battery ground connection  on painted block caused starting problems.jpg


Replacing battery cables with new ones solves most problems.

Battery cable new.jpg


If you have a multi meter and can do voltage drop tests then follow this DENSO procedure to find where the high resistance connection is.

Have battery tested. The test is free at most auto supply stores.

The GP's and their controls are not draining power. You have high resistance connections in the battery cables which are inhibiting current flow under high load conditions.

Best if you identify your tractor more completely as sometimes it makes a difference. 2WD gear, 4WD gear or 4WD HSD

Dave
 

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Roadworthy

Well-known member
Lifetime Member

Equipment
L2501 HST
Aug 17, 2019
1,647
526
113
Benton City, WA
You may indeed have poor battery connections. My starting point would be cleaning the battery terminals themselves as well as the cable clamps. Then tighten the cables securely onto the posts. Follow the ground lead to the frame. Clean if necessary and ensure it's tight. If the battery has a good charge and is in fact a good battery as you say your problems may be gone. Incidentally, even a brand new battery can have a cell fail prematurely. A load test never hurts.
 

england006

New member

Equipment
b7500
Jun 11, 2021
11
0
1
ohio
yes it was the battery, it read 12.5 so I trickle charged it overnight and it was 10.2 in the morning. must have had a damaged cell. thanks for the help!
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,249
1,030
113
Williamstown Ontario Canada
yes it was the battery, it read 12.5 so I trickle charged it overnight and it was 10.2 in the morning. must have had a damaged cell. thanks for the help!
Thanks for the final chapter. v it helps nus all learn

When you said in your first post: Battery is good .

Where did that statement come from. Your assessment of its age, you tested it in some way............

Dave