B80 8 speed. Need ideas

[ERICM1 0]

I have a 1977 B80 8 speed. Started no problem 1st time after winter storage. Drove it around a bit turned it off and had difficulty starting. Jumped the starter motor from the battery to check solenoid because I was getting no click from it at all and it spun the starter motor freely without throwing out and engaging. So I run off to parts store change the solenoid, buy new battery in case the old is not holding charge &.....nothing. no click, OHM meter jiggling backwards a little bit but not showing + reading at all. So this leads me to believe either fuse, ignition switch or safety switch. Fuse looks good ( No breaks ) heres a few questions.

1) Any body know how to test the ignition switch so I dont go buying more parts I don't need?

2) Where's the safety switch on this thing?? It may have been pulled already.

 

Thanks in advance for the help

[rmaynard 14,897]

There are two safety switches. One on the PTO lever, and the other activated by the clutch pedal. Here is the wiring diagram.

 

 

You also mentioned that there was no throw-out when the starter turned. That is not uncommon for a starter that has been sitting for awhile. You need to clean the Bendix assembly and do not lubricate it, as oil and grease only attract dirt and will soon create the same "no throw-out" situation.

 

You should have 12 volts to one side of the solenoid at all times. The other side goes to the starter. Starter is grounded through the body, to the engine, frame and back to the (-) of the battery. Taking a jumper from the hot side of the solenoid and touching the small lug on the solenoid should do the same thing as turning the key with all safety switches working. However, by using the jumper, you are eliminating everything that could be a problem. If the starter turns over, then you can go back and trace your circuit to find where the problem is.

 

Hope this helps.

 

[ERICM1 0]

Gotcha. Thanks for the input & sorry for late reply. I think the safety switches may have been cut out. Any input on where they are physically located on the actual machine? Maybe a description on what I'm looking for?? because the way it's acting its either the ignition switch or a safety switch I cant find

[rmaynard 14,897]

Clutch safety switch is located in front of the clutch pedal. It is a ball switch that is mounted in a bracket attached to the frame. You should see two wires attached to it, one of which goes directly to the solenoid. The PTO switch is the same type of ball switch, and it is mounted in the dash tower, directly behind the PTO lever.

 

Here's the clutch switch

 

and the PTO switch location

 

Edited April 23, 2014 by rmaynard

[ERICM1 0]

They are both cut out and bypassed. New fuse put in. Starter motor spins when hot wire put directly to it and als spins when put to the solenoid. So what do you think? ignition switch bad?

[rmaynard 14,897]

So if the solenoid is engaging when you put direct 12 volts to it's coil, then my guess would be something to do with the rest of the circuit. The power to the ignition switch come from the wire connected to the hot side of the solenoid, to the ammeter, through the ammeter to the battery terminal of the switch. Sometimes the connection to the back of the ammeter is bad, and sometimes the ammeter itself is bad. You can bypass the ammeter and connect both of those wire together to eliminate the ammeter as a problem.

[rmaynard 14,897]

By the way, . Sorry I didn't say so sooner. Glad to have you aboard. When you get a chance, post some pictures of your B-80. Everyone likes pictures. I have 2 1977 B-100's. The B-80 is a great tractor.

[ERICM1 0]

Thanks for the welcome. I agree it's a great tractor. The fact is I have had it for 15 years as my mower and work horse in the yard & have never had a problem. Except for a flat tire and replacement of a solenoid this is the most I have had to work on it and the first time it has baffled me.