Technical: Electrical- testing for solenoid or starter switch problem

[phartman]

1934 Ford Pickup converted to 12 volt and GM style 3-wire alternator so that I can run gauges and an idiot lights. Same starter solenoid as on my '61 that Ford used from the mid '50s-88.

Went to start the truck, and got low current, then no current when I turned the key and lifted the ignition lever. Normally I can hear the fuel pump come on after lifting the ignition lever and before hitting the starter button. Now, nothing. No fuel pump, no gauges register.

Battery is fully charged.

Thinking it was the starter solenoid, I replaced it. When I turn the key now and lift the ignition lever, at first I heard the solenoid click; now it buzzes as soon as I lift the starter lever.

Where should I begin my diagnosis? Bad ignition switch? Bad starter solenoid?
Not sure what my next step should be?

Thanks for the guidance.

[phartman]

I am wondering if I didn't inadvertently hook up the replacement solenoid wrong.... if the solenoid is buzzing then I assume juice is going to it. It should not unless I have the starter button pressed.

[Tinker]

Solenoids rarely are bad. Guess anything is possible with a new one.


Basically it is a through point. Neg or Pos on the "large" posts (same). A opposite polar on the 3rd small post.

[AKCJ]

I’m also having the buzzing solenoid problem on my 37 coupe. Internet research says bad connections or low/bad battery.
Had the battery tested and cleaned all the connections but that didn’t fix it. Pulled the starter and looked inside, brushes and all look fine.
After all this it turned over a few times but now it’s back to the buzzing solenoid.
It’s 12v negative ground.
Using an ohm meter, I’m trying to measure resistance through each leg of the circuit but I don’t really know what I’m looking for. Is 1 or 2 ohms normal?

[V8COOPMAN]

Originally Posted by phartman

Thinking it was the starter solenoid, I replaced it. When I turn the key now and lift the ignition lever, at first I heard the solenoid click; now it buzzes as soon as I lift the starter lever.

Where should I begin my diagnosis? Bad ignition switch? Bad starter solenoid?
Not sure what my next step should be?

There are quite a few DIFFERENT solenoids available. The one you want will be electrically wired as below.




Something like this Cole-Hersee (Click the link BELOW):

https://www.amazon.com/Continuous-Te...762603&sr=8-14




You must also make sure to wire BATT to the proper BIG LUG....it makes a difference!


"BAT" Marking....

[phartman]

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Originally Posted by AKCJ

I’m also having the buzzing solenoid problem on my 37 coupe. Internet research says bad connections or low/bad battery.
Had the battery tested and cleaned all the connections but that didn’t fix it. Pulled the starter and looked inside, brushes and all look fine.
After all this it turned over a few times but now it’s back to the buzzing solenoid.
It’s 12v negative ground.
Using an ohm meter, I’m trying to measure resistance through each leg of the circuit but I don’t really know what I’m looking for. Is 1 or 2 ohms normal?

I have had these solenoids freeze up on me. Used the same on my 1990 F150, and twice the solenoid froze closed. The clicking you should hear is the solenoid opening and closing. But twice line froze closed and caused the truck to continue us cranking after releasing the key.

The solenoid then was making a similar noise as my '34 is making now.

[phartman]

Short video on how to test the solenoid:

https://m.youtube.com/watch?v=ZyBV-FLtVf0

[phartman]

Parts store tested the battery- fully charged but only 8 cca out of 665. Shot, completely shot. Did not realize a battery can take a full charge but have no capacity to carry a load. Learn something new every day.

[AKCJ]

Good to hear you found the problem.

My battery tested good. I also tried jumping with another battery so I’m pretty sure it’s not the battery in my case.
I’m planning to pull the starter again and try to figure out how to test it other than just spin it on the bench. Maybe it spins ok with no load but draws too much current when trying to turn over the engine.
Even though I cleaned all the connections it could still be a bad cable.
If anyone has suggestions I’d like to hear them.

[sidevalve8ba]

Pete, just for curiosity sake, how old was that battery? Any idea?

Ted

[5851a]

Does the solenoid have a good ground?

[V8COOPMAN]

Originally Posted by 5851a

Does the solenoid have a good ground?

An old Ford solenoid with TWO large lugs & ONE small lug, operated by grounding the SMALL lug via the start button, DOES NOT require grounding of solenoid body. The START button, however, should have solid path to GND when button is pushed.

Coop

.

[phartman]

Originally Posted by sidevalve8ba

Pete, just for curiosity sake, how old was that battery? Any idea?

Ted

Yup. 8 years old. The parts guy told me the only reason it lasted that long was because it always had a trickle charge on it.

[phartman]

Installed the new battery, cleaned all the connections and grounds, and the truck fired right up!

[Tinker]

Good battery and clean connections win again. Not a faulty solenoid, which rarely or never fail if installed and wired correctly.

[Tinker]

Originally Posted by V8COOPMAN

An old Ford solenoid with TWO large lugs & ONE small lug, operated by grounding the SMALL lug via the start button, DOES NOT require grounding of solenoid body. The START button, however, should have solid path to GND when button is pushed.

Coop

.

Yep.... reason the small post is there on 3 post soleniods. The later 4 posts from tractors give a pre-jolt to the dizzy like the 50's.


It's a coil controlled by outside wires and never is it grounded like a starter with one wire to it through the body.

[5851a]

Originally Posted by V8COOPMAN

An old Ford solenoid with TWO large lugs & ONE small lug, operated by grounding the SMALL lug via the start button, DOES NOT require grounding of solenoid body. The START button, however, should have solid path to GND when button is pushed.

Coop

.

Thanks I should have remembered that.