Voltage drop in secondary starting circuit

[Mr Mower Man]

I have a Land Pride ZTR (ZSR54) in the shop with a starting problem. The engine is a Kawasaki FX730V-AS08-R. I diagnosed it rather quickly as a starter solenoid problem (it's a solenoid shift starter). The solenoid energizing wire was hot, but the battery voltage wasn't always getting over to the starter side of the solenoid. So I get a brand new $150 solenoid from Kawasaki today, put it on the starter...and it still does the same thing. Sometimes the starter engages, and sometimes you just hear a click. So instead of using a test light like I did the first time, I decided to get a volt meter out and take some actual readings. The solenoid energizing wire, when it's unhooked from the solenoid, gives me a reading of 12V. But when it's hooked up to the solenoid, when I turn the ignition key and the solenoid "clicks" but the starter doesn't engage, I get a reading of only 6V at the solenoid energizing terminal.

I feel like I'm missing something elementary from those voltage drop classes I took from Briggs & Stratton 2 or 3 years ago. Seems to me that if I check the circuit without the starter and get 12V, and then check the circuit with the starter and get 6V, the problem has to be in the starter, right? But I feel like I'm not remembering something. If so, I'm sure you guys here will be able to set me straight.

[38racing]

when I has that same issue it was a bad connection at the S tab of the keyswitch

[KE4AVB]

This was problem on some JDs where the fix is to wire inline a relay as there was too much voltage drop in the trigger circuit which was causing starting problems. The additional relay being of lower current needs to engage feed power right at the starter solenoid to the trigger side.

[RJRacing]

check the voltage at the battery when trying to start

[bgsengine]

I have a Land Pride ZTR (ZSR54) in the shop with a starting problem. The engine is a Kawasaki FX730V-AS08-R. I diagnosed it rather quickly as a starter solenoid problem (it's a solenoid shift starter). The solenoid energizing wire was hot, but the battery voltage wasn't always getting over to the starter side of the solenoid. So I get a brand new $150 solenoid from Kawasaki today, put it on the starter...and it still does the same thing. Sometimes the starter engages, and sometimes you just hear a click. So instead of using a test light like I did the first time, I decided to get a volt meter out and take some actual readings. The solenoid energizing wire, when it's unhooked from the solenoid, gives me a reading of 12V. But when it's hooked up to the solenoid, when I turn the ignition key and the solenoid "clicks" but the starter doesn't engage, I get a reading of only 6V at the solenoid energizing terminal.

I feel like I'm missing something elementary from those voltage drop classes I took from Briggs & Stratton 2 or 3 years ago. Seems to me that if I check the circuit without the starter and get 12V, and then check the circuit with the starter and get 6V, the problem has to be in the starter, right? But I feel like I'm not remembering something. If so, I'm sure you guys here will be able to set me straight.

do a ground side voltage drop between the solenoid housing and B- , may find a bad ground connection somewhere?

[Luffydog]

I had one last week come in for the same thing but he picked it up before I could get to it suppose to be coming back in next week. I know that does help u out but issues r the same. My first thought when he dropped it off was either a bad ground or relay that is starting to fail or bad or weak battery without the proper cca. If it shows back up I will post what I find but if not I'll watch this thread as you post. We r in a drought here of some what so I find it hard to see it Come back in before rainfall. Let u know what you find out.

[KE4AVB]

Do a ground side voltage drop between the solenoid housing and B- , may find a bad ground connection somewhere?

I probably going as clear as mud here.

When doing this test you want to make sure you are using the battery negative post and not the cable at the post. I have seen where the connection at the cable terminal to be a problem cause strange voltage drop outs. Otherwords if there is a problem in the grounding (negative return) between the starter solenoid or starter it will show up as a voltage and not the zero reading that you should get while trying to crank. If you do a voltage present just leave the metering lead on the negative post and gradually move the other meter lead along the ground (negative return) path until you no reading. Once find where it has no reading you just passed the problem area. Depending how the wiring is set this just a loose or rusted cable connection to the frame. Once you get a zero leave the lead at that point and use the lead that is negative post and start going back to the solenoid if it is a bad area it should show up as soon as you pass it.

Now with that said your voltage drop can also be on the positive side which basically you to same thing except you start at the solenoid trigger lead and work back to the Positive battery post. And then you to isolate where the drop occurred.

What you are checking for is resistance that shouldn't be there which shows up as voltage drop. As I said JD had a lot problem with both Kawasaki and Kohler shift starters at one time where the wiring in the start circuit had too much of voltage drop even when there was physical problem other than wire size being too small.

I know it is pain doing this but sometimes takes it to find the problem. I have spent half day chasing a bad connection.

Meanwhile I got to find my wake up juice (coffee) as I am about half asleep.

[38racing]

This was problem on some JDs where the fix is to wire inline a relay as there was too much voltage drop in the trigger circuit which was causing starting problems. The additional relay being of lower current needs to engage feed power right at the starter solenoid to the trigger side.

I had to add that relay on a jd 160 I was given. Part of issue I think is that starting circuit when through keyswitch twice plus the regular switches.

[Mr Mower Man]

do a ground side voltage drop between the solenoid housing and B- , may find a bad ground connection somewhere?

So exactly how do I do this? You'll have to spell it out for me.

[38racing]

do a ground side voltage drop between the solenoid housing and B- , may find a bad ground connection somewhere?

So exactly how do I do this? You'll have to spell it out for me.

Go to section 17.35 of this
http://web.ncf.ca/da229/smallengine/mtd ... ical-2.pdf