OLDSRIP
New member
Hi all,
Looking for some help on a electrical problem that is driving me nuts.
Tractor is a Mid 80's JD 420 lawn tractor with front and rear pto's and a front loader.
My problem is with the pto circuits. I am not getting any dash lights and no power to the pto's. the pto work when hot wired. I have the factory manual and am following the flow chart. Problem is the flow chart keeps telling me that different wires are open. How ever when I check these wires 1 by 1 they check out good.
The oil press and charge light work good.
When checking the pto switch power, it says to check for power at switch terminal with yellow and purple. Voltage IS present with key on. Book says that means Purple wire to pto switch is open. It is NOT open when checked with a dvom.
Power test at TDC module, it says ck power at pink and purple wire terminal. Voltage IS present. Book says purple wire to pto light switch is open. Again, it is NOT open.
This next test at the 20 amp fuse. I have voltage on both sides. Book says to replace pink wire to 8 pin connector. Again I check this wire and it is good. NOT open. This wiring harness has not been hacked and is in good shape.
All 3 of the starter safety switches work, the 2 pto switches and the transmission neutral switch.
The only safety switch that is not there is the seat switch. Missing for years ever since I have owned it.
I do have a question on the seat circuit. The 2 pink wires that go to the missing switch have continuity between the pink wires even though there is no jumper wire. That doesn't look right to me. But I checked both wires by ending the loom and they are fine.
I am guessing the Time delay control module may be bad. But I don't like to quests and throw parts at a problem.
This is the early model with the external grounds and the grounds test good.
Anyone out there willing to help? I will run any test suggested.
Also, does the TDC do screwy things like this when they go bad?
This tractor is in nice shape. I know I can hot wire the switches, but I am going to sell this since I bought a bigger tractor and would like to have all the safety equipment working.
Thanks, Joe W
Oldsrip@yahoo.com
Looking for some help on a electrical problem that is driving me nuts.
Tractor is a Mid 80's JD 420 lawn tractor with front and rear pto's and a front loader.
My problem is with the pto circuits. I am not getting any dash lights and no power to the pto's. the pto work when hot wired. I have the factory manual and am following the flow chart. Problem is the flow chart keeps telling me that different wires are open. How ever when I check these wires 1 by 1 they check out good.
The oil press and charge light work good.
When checking the pto switch power, it says to check for power at switch terminal with yellow and purple. Voltage IS present with key on. Book says that means Purple wire to pto switch is open. It is NOT open when checked with a dvom.
Power test at TDC module, it says ck power at pink and purple wire terminal. Voltage IS present. Book says purple wire to pto light switch is open. Again, it is NOT open.
This next test at the 20 amp fuse. I have voltage on both sides. Book says to replace pink wire to 8 pin connector. Again I check this wire and it is good. NOT open. This wiring harness has not been hacked and is in good shape.
All 3 of the starter safety switches work, the 2 pto switches and the transmission neutral switch.
The only safety switch that is not there is the seat switch. Missing for years ever since I have owned it.
I do have a question on the seat circuit. The 2 pink wires that go to the missing switch have continuity between the pink wires even though there is no jumper wire. That doesn't look right to me. But I checked both wires by ending the loom and they are fine.
I am guessing the Time delay control module may be bad. But I don't like to quests and throw parts at a problem.
This is the early model with the external grounds and the grounds test good.
Anyone out there willing to help? I will run any test suggested.
Also, does the TDC do screwy things like this when they go bad?
This tractor is in nice shape. I know I can hot wire the switches, but I am going to sell this since I bought a bigger tractor and would like to have all the safety equipment working.
Thanks, Joe W
Oldsrip@yahoo.com