Ford 3600 Fuses or Solenoid

Question for you folks. Had a wiring issue a few weeks ago I traced it back to broken fuse line at the solenoid. Wired in new fuse and all was good.

Just out of the blue I have no have a no start issue. I have traced out my wiring with multimeter and everything looks good. Power at battery, switch, altnator, and when I turn the key I verified I got 12v to the wire going to the blade connector on the solenoid.

Its kind of hard to get to I couldn't get it to jump on the tractor but I put 12 volts external to the solenoid and did hear it click.

Before I pull the starter/solenoid this evening anyone thing of a fuse or something I missed?

Can you get to the starter/solenoid with your meter?

If so, check the voltage at the spade terminal with the wire connected while holding the start switch on.

If the reading is low, below 9VDC, there is too much voltage drop. Could be a failing neutral switch, a weak starter switch, a loose, bad corroded connection somewhere between the battery (the fuse you just replaced) and the solenoid.

Keep checking, working back from the solenoid until you find the drop. It must be tested under load, holding the switch to start.

If you have good voltage at the spade terminal, check the voltage at the stud going into the starter itself, after the solenoid. If there is voltage there while holding the start switch, the starter is bad. Probably bad brushes.

If good voltage at the spade and no or very low voltage at the starter stud, the solenoid is bad or may just need to be cleaned inside. Sometimes dirt and oil collect inside the solenoid and starter and gum up the works.

Since this started when you replaced the fuse, there may be voltage drop at the new fuse holder. Might consider replacing the fuse with a fuse link. A fuse link is a sacrificial link of wire designed to burn out if there is an overload. It will give better connection, less resistance than a fuse holder especially if it is exposed to weather and vibration. Size the fuse link to approximately the output of the alternator if the alternator charges through the link. If not, then about a 40 amp will be sufficient.

Thanks I'll need to get a helper that can turn key while I try some of this.

I did bypass the neutral switch to eliminate that, and see the good voltage to my connector going to the spade. There may not be enough room to put the conenctor on the spade at solenoid and get meter in but I will try that.

The fuse link had an ring connector on the solenoid that is what broke I cut that wire back and wired in a 20amp fuse, solder connections etc. Fuse ohm'd out and looked good, but will reverify everything.

Which stud would I check at the starter? I have the solenoid connecting with 2 studs connecting down to the starter. with a good solenoid it should make the connection for those to conenct then voltage to flow down to starter.

I just to get better access to it i may pull it an put it on the bench to test it out.

Hello Luke0927,

If the starter is not engaging then you have no voltage at the solenoid side of the starter. Take a jumper
wire and go from the battery side of the solenoid, to the small ignition wire at the solenoid.

You already know which one it is, as you said there are 2 small wires and one is the safety switch. If
the starter does not engage, providing you have a good battery, then the solenoid is bad.

More likely you have a voltage drop though. You NEED to check voltages when you have the key turned in
the start position. Start at the battery, and work your way down to the solenoid,

Guido.

since you can hear a click when you put 12 volts on the spade lug start lead.....

You either have a bad ground
or a bad pos cable to the main connection
or... a bad solenoid that is not passing current.

I'm guessing the selenoid has a bad contact inside but could be the first two items.

since you can buy a new starter off ebay for around $110, it usually cheaper overall to just replace it. As always, clean all connections replace any suspect cables. Remember the selonoid main cable connects to a copper stud so dont over tighten it or it will strip very easily.

In the old days, we would take the seloniod apart and turn over the copper washer, and clean the two big bolts that acted as the contacts, but this is difficult to do successfully on the current generation of starter. After all "Lucus" is the prince of darkness.... as they say.(english joke about lucas electrial parts)

Careful testing with the neutral safety bypassed, I almost ran myself over like that. Good thing 1st is so low on the 8 spd!

Thanks Folks should have time and a helper to do some more testing this evening.

Will post up my findings and if any questions.

Hello folks If you could help me verify what I tested please but I think it is the solenoid.

With the switch off I verified I have ~13v at the battery and at the starter lug where the hot lead and fuse link connect.

When trying to start the tractor with my MM connected to the wire that goes to the spade on the solenoid I test 13v.

With the wire connected at the spade measuring on the spade voltage is 0.

When I turn the key if I also measure at the hot lead on the starter where fuse link and battery lead go my voltages drops to 0v.

With the key off if I make a jumper and go from the hot lead of the starter up to the spade connector I'm not getting a click or starter engage.

Something I would like to under stand. This switch has 3 postions, 1st turn I still measure 13~v at the starter lug, if I turn it to the 2nd position my voltage goes to 0v, if I try and turn the key fully to start I do read that ~13v at the wire going to the spade.

What is switching or happening for me to loose the voltage on the 2nd position of the key swtich?

your describing...


very bad battery cable connections that have a very very high resistance as most likely cause...

or a battery that have a broken internal connection with a very very high resistance...

Load test or switch the battery with a known good one... it same, replace both battery cables...

fuseable link and wire to ignition switch is bad or down to one strand...

for instance add a jumper cable between negative battery post and one of the three mounting bolts on the starter to see if the negative battery cable is bad...but you must touch the battery post, not the possible bad cable.

Really appreciate the help.

I pull a battery from my diesel truck tomorrow and see results, I don't have any extra battery cables but worse case I'll make some tomorrow won't hurt to have them on tractor. The terminals look really clean but the wires have been wrapped for years in electrical tape so maybe could be it.

How could I load test a battery at home (would like to know for knowledge)? I did just put it on the battery and hit the key and voltage did stay at the battery.