getting signal to new solenoid, still won't engage starter

slomo

Well-Known Member
Joined
Jul 14, 2019
Threads
24
Messages
906
I know bad grounds can often be the source of the problem. Been through that a few times. This "seems" to be something else though. I've already removed the frame ground and reattached it, and the battery post and terminals look brand new. It has the automotive style round lugs and everything is tight and clean. Starter spins and cranks the mower easily when I run a small positive wire directly to the spade on the solenoid. Just touch the wire to it and it engages. Getting the same 12V charge from the wiring harness (when key is turned to "start" of course) and nothing but "click"

Somehow, the 12V + from the wiring harness is different from the 12 V + direct jumper wire

Edit: would also like to add that "sometimes", like 1 out of 10, the thing will actually crank with the key. Most of the time it will not. Although it will click every time.
Ignition switch or solenoid is bad.

First thing I look at is grounds. Most people neglect it or overlook them. They attack the + wires all day.

slomo
 

slomo

Well-Known Member
Joined
Jul 14, 2019
Threads
24
Messages
906
this ^^^^^^

i just spent a day chasing the same symptoms as you even after i replaced the battery

so next i replaced the solenoid and no joy, then the wire from solenoid to starter and still not working so i replaced the starter and still does nothing but click (all were confirmed good working used spare parts i keep on hand from mowers i scrapped)

after all that i went back to my shade tree mechanic days and broke out the jumper cables and jumped all power connections from battery to the source

turned out all it was was the main ground connection from the frame was corroded and no longer letting any amps flow yet it still read 12v on the test meter with everything. made a new ground point and connections and its all good now
Yup, jumper cables do other things too. (y)

slomo
 

cbs123

Member
Joined
May 26, 2020
Threads
6
Messages
24
You probably have a corroded connection somewhere in the circuit. No load you will measure battery voltage through considerable resistance. Try this test. Connect volt meter to positive on battery and the other lead to the signal wire at the solenoid but have the signal wire connected to the solenoid. When you turn the key and you get the click see what the voltage is. It should be less than about half a volt but i will bet it it is in the 4 to 6 volt range which indicates a bad connection somewhere in the circuit from the battery to solenoid.

Thanks everybody for the replies.

Haven't had a chance to check it for last couple of days. I just performed this test, and sure enough it goes from 12.5 V to 6 V when I turn the key. So the issue must be in the wiring from the key switch to the solenoid. Bad thing is, it travels through a PTO switch (which I've already tried a new switch in, as well as a new ignition switch) and three safety switches, and a harness connector. I suppose I can perform the same test through each switch or connector and try to narrow down where the problem is. Or will that work?

Thanks Hammer for that good adivce, much appreciated
 

cbs123

Member
Joined
May 26, 2020
Threads
6
Messages
24
well that is just it, in my case and possibly yours as well, the positive wire has full voltage and amp capacity but the ground wire to mower frame bad connection was where no amps are being allowed to flow. the ground wire is where you need to look. hook jumper cables from battery ground to the engine fins and i bet it fires right up
Just tried that. Still just clicks. I'm thinking a weak connection somewhere in + side of wiring. Gotta love wiring problems lol
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
45
Messages
10,556
Run that same test at the battery. If it drops below 9V, bad battery. If it is 10V or more battery good and you must then proceed down the positive side, testing each connect to find where you have a voltage drop. Pain in the butt, just like most electrical troubleshooting. Patience and an assistant will be of great help to you. Good Luck.
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
12
Messages
1,619
These kinds of problems are just so much fun. First thing is one at a time pull the connector off of the switches and plug back in about ten times to "clean" the connectors. If it starts working you need to fix the bad connection. Clean or replace the spade connector pins. If that doesn't work will need to bypass each switch one at a time till you find the bad switch. The test you did was a voltage drop test. A good reading is less than half a volt not battery voltage. You are testing the current carrying ability of a part of a circuit. It seems counter intuitive to some folks not measuring to ground but on the same wire. When you find the problem do the test again and see if you get about half a volt. Good luck.
To make life easier disconnect the wire from the solenoid and connect a 12v bulb to it and ground then pull the connector off the ignition switch and jump the B and S terminals. This should give you a dim bulb. When you find the problem the bulb will go bright. Save you massive time not having to keep turning the key to test.
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
12
Messages
1,619
Thanks everybody for the replies.

Haven't had a chance to check it for last couple of days. I just performed this test, and sure enough it goes from 12.5 V to 6 V when I turn the key. So the issue must be in the wiring from the key switch to the solenoid. Bad thing is, it travels through a PTO switch (which I've already tried a new switch in, as well as a new ignition switch) and three safety switches, and a harness connector I suppose I can perform the same test through each switch or connector and try to narrow down where the problem is. Or will that work?

Thanks Hammer for that good adivce, much appreciated
To test at each switch or connection you need to add a load. Meter won't find the problem.
 

StarTech

Lawn Addict
Top Poster Of Month
Joined
Feb 19, 2020
Threads
5
Messages
2,287
Bad connections and long wire can cause huge voltage drops under load. Place your meter leads across the starter relay control wires and try starting. What is the voltage across the solenoid? IF under 10v then work your way back to battery by the voltage at control switch. Once you go to full battery you have pin pointed the problem as do voltage drop tests under load. Bad gronds is just one source of problems. Bad Packard wire terminals cam be another source as the spring contact hinge breaks. Or just the starting I just repaired yesterday. The B (battery) terminal of the ignition switch had 12v until I tried starting then it would drop completely out. It turned out to be the positive battery terminal at the solenoid where the ignition B power supply provided had corroded internally. Same thing can happen on the negative cable. The terminal might be clean on the outside but corroded on the inside; Hence, why we do voltage drop tests to find a bad connection.

Now on JD with Kawasaki or Kohler solenoid shift starters I have added help relay due huge voltage drops the starter trigger wiring run.
 

cbs123

Member
Joined
May 26, 2020
Threads
6
Messages
24
These kinds of problems are just so much fun. First thing is one at a time pull the connector off of the switches and plug back in about ten times to "clean" the connectors. If it starts working you need to fix the bad connection. Clean or replace the spade connector pins. If that doesn't work will need to bypass each switch one at a time till you find the bad switch. The test you did was a voltage drop test. A good reading is less than half a volt not battery voltage. You are testing the current carrying ability of a part of a circuit. It seems counter intuitive to some folks not measuring to ground but on the same wire. When you find the problem do the test again and see if you get about half a volt. Good luck.
To make life easier disconnect the wire from the solenoid and connect a 12v bulb to it and ground then pull the connector off the ignition switch and jump the B and S terminals. This should give you a dim bulb. When you find the problem the bulb will go bright. Save you massive time not having to keep turning the key to test.
Awesome advice, thanks a lot for the help!

Unfortunately we are still wrestling this bear. I made a light tester like you mentioned. But the bulb seems to be just as bright when testing it on the solenoid wire as when connected directly to the battery. Either way, its a good idea and one ill use in the future I'm sure. As well as jumping the ignition packard. We've been working for hours trying to find the source of our anguish. I'll let yall know if I ever find the problem with this thing
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
12
Messages
1,619
Something not right. If light is same brightness should have enough current the power solenoid.
If you connect wire from batt+ to small terminal on solenoid engine cranks over at proper speed (y/n)
Remove trigger wire from solenoid and connect meter from batt- to trigger wire and turn key to start. What is the potential voltage measured?
Reattach trigger wire to solenoid. Connect meter to batt- and trigger wire connection at solenoid. Turn key to start. What is measured voltage?
Move meter to batt + and trigger wire connection at solenoid. Turn key to start. What is the circuit voltage measured?
 
Top