245 Electrical problems

[Tyler Sperry]

Hello everyone. I'm still working on getting our Massey back into working order. It finally runs, but aside from a few new leaks, the electrical system seems to be doing some weird stuff. I am no expert in electrical. I know some basics but not really enough to get any useful diagnostics on the problem.
Anyways, I had been reading up on some forms and scouring the diagrams as to why the tractor is doing what its doing. I had seen on some of the forum discussions that there is a oil pressure switch somewhere that energizes the gauges? If so where is that located? As it seems that could be my problem? If not what should I check, and what should I check for?

Currently I get a oil pressure reading and a tachometer reading just fine since they are both mechanical. My work and head lights seem to work just fine. The gauge lights don't but I suspect my grandpa never changed those bulbs lol. The Amp/voltage meter only shows a drop when I hit the key to start the tractor then its back to neutral. Doesn't show a charge or anything. And I'm not entirely convinced the alternator is putting out enough power to charge the battery at the very least. I also am not getting any readings from the fuel or temperature gauge. Id really like to have the temperature gauge back at the very least. I have the hood off at the moment, so if I need to replace the fuel sender not a big deal. But if it works, I don't want to have to replace that if I don't have to. Same with the thermostat.

I have replaced the battery and the battery leads since both were not only old, but not making good contact and were beyond heavily corroded. With those the tractor does start far better than it had, no longer requiring a jump pack or jumper cables.

Any advice would be greatly appreciated!

 

[Jim.ME]

Do you have the Massey Ferguson Operator's manual, Service Manual, and Parts book that are correct for your tractor's serial number? Some of the manuals were for specific serial number ranges. The parts book can be accessed and used online.

The oil pressure switch should be found installed into a tee right at the rear of the oil pressure gauge.

The fuel and temperature gauges were electrical gauges originally. The oil pressure switch provides power to them. It is not uncommon for fuel gauges not to work. temperature gauges are more likely to still work.

Depending how the alternator is wired into the electrical system it might not show a charge, if it was not wired through the ammeter. If all load wires and the alternator wire are all on one ammeter terminal and the battery power wire from the solenoid is on the other, it will show amps being returned to the battery, it will not show amps supporting any loads on the same terminal it is connected to. Use a handheld voltmeter with the leads connected to the battery posts to check the voltage when the engine is running about half throttle. It should be 13.6-volts or better after running for a bit.

Test the temperature gauge and fuel gauge by unhooking the sender wire. use a jumper wire to short the sender terminal of the gauge to ground, if the gauge is good the needle will swing full scale. If the needle doesn't move the gauge is bad. You can test the fuel sender by removing it, hook one lead of an ohm meter to the mounting surface (must be shiny clean for good contact) and the other lead to the terminal for the wire to the gauge. With the meter on its low scale, you should see the ohm reading change as you move the arm from empty to full positions. You do similar with the temperature sender. Suspend it in a pan of water with one lead to the body and one to the terminal. The ohm reading should change as the water heats up. It is best to have a thermometer in the pan as well so you can note ohm readings as the water heats to different temperatures. Ohm ranges for electric gauges and senders have to match for correct readings. Unfortunately, I don't see that info given in my 245 manuals.

 

[Tyler Sperry]

Do you have the Massey Ferguson Operator's manual, Service Manual, and Parts book that are correct for your tractor's serial number? Some of the manuals were for specific serial number ranges. The parts book can be accessed and used online.

The oil pressure switch should be found installed into a tee right at the rear of the oil pressure gauge.

The fuel and temperature gauges were electrical gauges originally. The oil pressure switch provides power to them. It is not uncommon for fuel gauges not to work. temperature gauges are more likely to still work.

Depending how the alternator is wired into the electrical system it might not show a charge, if it was not wired through the ammeter. If all load wires and the alternator wire are all on one ammeter terminal and the battery power wire from the solenoid is on the other, it will show amps being returned to the battery, it will not show amps supporting any loads on the same terminal it is connected to. Use a handheld voltmeter with the leads connected to the battery posts to check the voltage when the engine is running about half throttle. It should be 13.6-volts or better after running for a bit.

Test the temperature gauge and fuel gauge by unhooking the sender wire. use a jumper wire to short the sender terminal of the gauge to ground, if the gauge is good the needle will swing full scale. If the needle doesn't move the gauge is bad. You can test the fuel sender by removing it, hook one lead of an ohm meter to the mounting surface (must be shiny clean for good contact) and the other lead to the terminal for the wire to the gauge. With the meter on its low scale, you should see the ohm reading change as you move the arm from empty to full positions. You do similar with the temperature sender. Suspend it in a pan of water with one lead to the body and one to the terminal. The ohm reading should change as the water heats up. It is best to have a thermometer in the pan as well so you can note ohm readings as the water heats to different temperatures. Ohm ranges for electric gauges and senders have to match for correct readings. Unfortunately, I don't see that info given in my 245 manuals.

Awesome! Thank you for this information! I do have 2 manuals for my tractor. A physical parts book with diagrams specific to the serial number, and a general maintenance manual, nothing that's too specific or serial number dependant. Both have been helpful up to this point lol. These issues have been harder for me to solve.

This information is a lot more helpful than what I could find anywhere in my books. Thank you very much! Ill give these a try here as soon as I get the time.