C-100 Ammeter Voltage Drop and Solenoid Fried?

[cslxt8 4]

So I started digging into a C-100 I acquired over the weekend and I have found two issues. One of which I am curious if anyone else has seen and the other I suspect the solenoid is toast.

 

I was not getting any power to the solenoid when turning over the key. Surprising enough both the clutch and PTO safety switches work (I wonder for how long), yet I was still not getting power at the solenoid. After working from the live hot wire on the solenoid I discovered the voltage was dropping from 12.5V to 3.4V across the Ammeter. After bypassing the Ammeter I got power to the ignition switch then to the solenoid when cranking. Just curious if anyone had seen something like this and where could I find a decent quality replacement, any suggestions?

 

Now that I got power to the solenoid, there was a loud click but the starter did not budge (I have not confirmed the starter is free not did I confirm power was passing through to the starter). However I observed that the power was continuing as if I was holding the key to the crank position. I am just curious if the solenoid is fried such that it is somehow sticking and jumping power? I checked the ignition switch and it is checking out fine as I would expect.

 

Thanks,

C

[ohiofarmer 3,265]

It's pretty easy to test a solenoid. Just apply a jumper wire to the center post. The starter should turn.

 Clicking does not guarantee function. The magnet inside clicks,but can still be stuck or the contacts can be corroded inside.

[ebinmaine 67,472]

5 hours ago, ohiofarmer said:

It's pretty easy to test a solenoid. Just apply a jumper wire to the center post. The starter should turn.

 Clicking does not guarantee function. The magnet inside clicks,but can still be stuck or the contacts can be corroded inside.

 

I've had experience with a bad solenoid clicking and still not being functional.

 

Solenoids are cheap enough at about 12 to 15 bucks to just replace.

Tell the parts store you want one for a 1975 f250 with 3 posts.

Bring your old one to see how the bracket is shaped.

 

 

6 hours ago, cslxt8 said:

. After working from the live hot wire on the solenoid I discovered the voltage was dropping from 12.5V to 3.4V across the Ammeter. After bypassing the Ammeter I got power to the ignition switch then to the solenoid when cranking. Just curious if anyone had seen something like this and where could I find a decent quality replacement, any suggestions

 

 I'm NOT a fan of ammeters.

 

They have a place in the world but not with me.

I replace ALL of mine with a voltmeter.

 

If an ammeter goes bad it can melt/burn down a tractor.... Or much worse.

If a voltmeter goes bad it's inconvenient, at most.

 

[953 nut 55,218]

[ohiofarmer 3,265]

I actually restored function to a solenoid by drilling a tiny hole where I hoped the drill bit would not hit anything important. I squirted some Deep Creep inside and the next day it worked again.

 

When you live "out here" it is sometimes best to avoid trips to town..I can also remember Dad starting tractors by jumping the solenoid. This was before keys were in our tractors. Farmers died every year when jumping tractors as they were standing in front of the rear wheel and forgot to take it out of gear.

 

I got a free 26 HP MTD  lawn tractor that had the magic smoke let out. It came with the battery cable cut as a result of the calamity caused by wiring the + battery to the ground by a guy who "repaired " lawn tractors.

Believe it or not the previous owner then took it to a second lawnmower shop and the repair guy hooked up another battery and let more smoke out after being told what happened the first time.So the second repair shop told the owner it would cost $800 to fix it. That is how i got it when the second shop cut the + cable with a side cutter.

 

I pulled some stuff apart and freed it up and it was a runner for about $75.

Both coils were Fried on that big Briggs.  Actually that is what saved that tractor, because the Mother of all Mouse Nests would have cooked the engine but good. It is a big unit with a 56" deck, but the frame twists and flexes and it uses twice the gas to cut the same size lawn as a cast iron Kohler K series.

 

 

Edited July 30, 2019 by ohiofarmer

[cslxt8 4]

Thanks for all the input, I got a new solenoid put on and with a few fuel delivery system tweaks it's now running! I have some bugs to work out on the carb yet though. I also need to find a good quality fuel pump or rebuild kit. I have not touched the Ammeter, just bypassed it for now.

[953 nut 55,218]

8 hours ago, cslxt8 said:

good quality fuel pump or rebuild kit.

Here is the place to get a good kit.   http://www.then-now-auto.com/kohler-fuel-pumps-2/