Starter solenoid help

Hello everybody, I need some help here. I bought a new solenoid for my MF 390, the old one was more than often for not working (a single click when turning the key and i had to to the key for minutes before i actually worked once)

So here is my major problem, remove the old one there was corrosion inside in it. Hooked it up to the fork (which i hope was the right way), plugged the cables exactly how they were. I had to put the booster since the batteries were weak. It started extremely well, so i removed the booster and went to eat. After an houri went back switched off the tractor. Tried to start it again. nothing.... when i went to touch the solenoid it literally burned my hand. What i find strange is the i had to unplug the negative of the 2 batteries so the the solenoid cooled down. Sadly i think that part it fried but i want to know what went wrong? Bad install, bad part, something else?

i know some basic mechanic but i far from being an expert

Hello dralon,

Sounds like bad contacts! You should just get a new one! Hard to
trusted now. Is it a
single wire? Make sure it is grounded if it is single wire.
Guido.

What I would do is get a voltage meter and with the battery hooked up take a voltage reading at the small wire that hooks onto your solenoid. It should read zero. If it shows voltage remove the small wire and check the voltage on the small wire terminal. If it still reads voltage then you may have a short some where. If the voltage did drop to zero then you have a bad starter switch.

Sounds like either your key is not returning when you release it or as a result of messing around with a low you caused the contacts in the solenoid to ark and weld together.

Was supposed to say; messing around with a low battery you caused the contacts in the solenoid to ark and weld together.
.
Why doesn't edit work anymore?

I'm going to say it was a bad solenoid. Unless you think the starter stayed engaged and ran with the engine
running... In that case there is more wrong than just a solenoid!

When you replace it, try starting it a few times. Like pinball said, check for voltage on the small wire with
it running. Another test would be to reconnect the batteries, touch the battery cable to the solenoid stud,
watch carefully for a spark, should be none. If it checks out, watch it for a while, be sure it's not heating
up.

Though I've never seen that happen before, if you go with the same brand solenoid, chances are there may have
been more than one bad one made.

Guido is probably right. Is the tractor a ford? Did you have the right solenoid? The Ford solenoid energized from a ground wire. Sounds like you energized the ground wire.

Today i will try it with the old one since the "new one" smell burned like crazy. The old one was a pain but i will clean it and see if i can make those electrical test. I doubt it is the switch since i never had trouble with it before.

The solenoid in question is for a Massey Ferguson 390
if you want to see how it look: https://allpartsstore.com/ItemDetl.htm?ItemNumber=VPF2207

I have 2 batteries so i plug the 2 cables and the small wire to the top stud and the lower one to the starter

Just to make sure i didn't do a mistake there since it is the only thing i am unsure, if you look at the solenoid picture, i attached the fork arm between the end and the tiny plate with the spring

Thank for all the tips, i will try again today that is if i have time the hot water tank died last night .. not a great week end *sigh*

When you initially hooked it up and connected the battery, if it did not try starting on its own indicates the circuit to energize the solenoid was open.
You turned the key and the solenoid pulled in and enabled starting, this indicates your wring hook up was sufficient to provide power from the key to the solenoid.
You said it got really hot.
Only two things that can cause this:
1-Key not returning which resulted in continuous flow of current through the coil in the solenoid leading to melt down.
2-Contacts in solenoid welded themselves together due to a high amp draw that will result when attempting to start with a low battery.

Both of these would have resulted in your starter running for the hour you left it, if this did not toast your starter completely it was probably the equivalent wear of starting the engine 600-700 times.
A third possibility is a mechanical jam caused when the solenoid was attached to the fork, maybe something you did incorrectly or maybe a manufacturing flaw; burr, ding etc.
This as well would have resulted in the starter remaining engaged.
Do you by chance recall a high pitched noise coming from the engine that is not normally there?