GF 1800 motor stops when pto is engaged

mrbig1too

New member

Equipment
GF 1800
Oct 21, 2014
3
0
0
Topeka, Kansas
I have a GF 1800 mower (diesel, hydrostatic) that the motor shuts off instantly when you engage the pto for the mower blades to run. I installed a new safety switch for the pto lever thinking that was the culprit. I removed the seat and jumped the seat safety switch and same thing still happened. I then jumped the pto kill switch on the other side of the mower and still no luck. The mower runs fine and the blades turn freely. I had a pack rat visit recently but I can't see any damage to the wires, in fact I can't tell where the wires start and finish as they are in conduit. What to do?
 

mrbig1too

New member

Equipment
GF 1800
Oct 21, 2014
3
0
0
Topeka, Kansas
The engine starts and runs fine and the mower can be driven at any speed. When the pto shift lever is moved to engage the blades the blades start turning and the engine shuts off. The blades turn freely. They are not stopping the engine. The engine just goes dead like the key has been turned off. Thx
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,191
2,061
113
Bedford - VA
The engine starts and runs fine and the mower can be driven at any speed. When the pto shift lever is moved to engage the blades the blades start turning and the engine shuts off. The blades turn freely. They are not stopping the engine. The engine just goes dead like the key has been turned off. Thx
Check the PTO safety switch.........bypass it and report back
 

mrbig1too

New member

Equipment
GF 1800
Oct 21, 2014
3
0
0
Topeka, Kansas
I jumped the pto safety switch and the seat safety switch and the same thing still occurs. Replaced the pto lever safety switch. The engine shuts off when the blades are engaged. Does the problem have to be somewhere in the wiring if it is not in the switches?
 

rentthis

Member
Lifetime Member
May 30, 2012
997
21
18
summerville,sc
Does the brake on your machine have to be set in order to start? I had one once and can't remember. If you have to press the brake to start, you might have a problem with a brake safety switch.
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,191
2,061
113
Bedford - VA
I jumped the pto safety switch and the seat safety switch and the same thing still occurs. Replaced the pto lever safety switch. The engine shuts off when the blades are engaged. Does the problem have to be somewhere in the wiring if it is not in the switches?

Has to be a broken wire or something in the mix, IF the switches are being bypassed ........can you take a switch out and test it for continuity with an OHM meter just to make sure that it is working when bypassed?
 

AZ.

New member
May 4, 2014
22
0
0
Arizona
Im having a problem following and Im sorry... Take off or unhook the mower deck? Make sure blades are spinning freely then focus on a electrical problem?
 

nick288

New member

Equipment
GF1800E
May 15, 2023
8
0
1
Fresno
MrBigOne, did you ever figure out what the issue was? I'm having the same issue on my GF1800...