Bench test lawn mower starter solenoid

Thread Starter

Circuits123

Joined Dec 7, 2012
64
I have an old riding mower that won't start. I tested the solenoid while it was still in the mower and I think that's the problem. But I'd like to double-check before I buy a new one. I've got it out of the mower on the bench now. Can anyone suggest how I can test it?
 

SamR

Joined Mar 19, 2019
1,505
Starters typically have a grounded frame and a hot connection from a relay. Pair of jumper cables neg to frame and pos to hot connect. Better to put the nut on the hot connect bolt and connect pos to nut instead of thread to prevent pitting threads.
 

LesJones

Joined Jan 8, 2017
2,417
When you say that "tested the solenoid while it was still in the mower and I think that's the problem." exactly what dis you do to test it ? Did you just test that you heard a clung when the coil was energised or did you verify that there was no output to the connector that goes to the starter motor. I am assuming it is just a relay type solenoid. (Not the type on a pre engaged starter.

Les.
 

Dodgydave

Joined Jun 22, 2012
8,586
Post a picture of the solenoid....

You can short out the two Big Nuts with thick leads to test for starting.
 
Last edited:

Thread Starter

Circuits123

Joined Dec 7, 2012
64
When you say that "tested the solenoid while it was still in the mower and I think that's the problem." exactly what dis you do to test it ? Did you just test that you heard a clung when the coil was energised or did you verify that there was no output to the connector that goes to the starter motor. I am assuming it is just a relay type solenoid. (Not the type on a pre engaged starter.

Les.
I tried the tests recommended on this YouTube video and got 7 volts instead of 12. This is what the solenoid looks like.
 

SamR

Joined Mar 19, 2019
1,505
Don't know why they want to call it a solenoid? It's just a 12V relay almost like the std. Ford starter relay except for a hot spade lug instead of a nut and bolt and lower ampacity of the contacts I'm sure. Sounds like it's contacts are damaged and needs replacing. Did you jumper the starter to check it?
 

Thread Starter

Circuits123

Joined Dec 7, 2012
64
Did you jumper the starter to check it?
I'm not clear on what the jumper start is, but I found another video and did the test he shows. The solenoid works when I connect it to the battery out of the mower. I get continuity between the terminals when it clicks. So, unless there's something else to it, I guess it works.
 

SamR

Joined Mar 19, 2019
1,505
12V battery and jumper cables. Neg to mower frame, pos to cable to the starter you took off the relay. Does the starter spin? If so just replace the starter relay. If not your starter is bad. You should be getting 12V across the relay so I would replace it. If the starter isn't spinning it is drawing all the amps it can from the battery and may be why the relay is damaged. Or if it doesn't spin the starter windings may be open and new starter needed for either case. Or just replace the relay and keep your fingers crossed that it is the only problem.
 
Top