School Bus Conversion Resources

School Bus Conversion Resources (
-   Mechanical and Drivetrains (
-   -   '99 Thomas no crank (

DJtwreck 09-22-2019 10:04 PM

'99 Thomas no crank
My 1999 Thomas Saf-T-Liner will not crank when I turn the key over or push the starter button in the rear. Batteries are charged up, all the dash lights turn on but when I push the start it's just one click from what I believe may be the solenoid. There are no door safety things that prevent starting. It's been a few months since I last drove it and had no problems with it then and I dont believe there as been any changes since.
3126b and Allison transmission.

Native 09-23-2019 05:09 AM

Have the batteries been maintained with a good charge? The CAT 3126 engine likes a lot of juice in the batteries.

DJtwreck 09-23-2019 10:39 AM

I believe so. I mean even when it's connected to a battery charger pushing 200A it still doesn't even attempt to crank.

ewo1 09-23-2019 11:23 AM


Originally Posted by DJtwreck (Post 350176)
I believe so. I mean even when it's connected to a battery charger pushing 200A it still doesn't even attempt to crank.

Do you have an electronic tranny?

The reason I ask is because if your push pad is dark, no lights then bus will not crank.

If not an electronic tranny then I would look at/for a neutral safety circuit that would prevent the bus from cranking.

Oh.... then there's the make sure your ignition switch did not go bad.

DJtwreck 09-23-2019 11:49 AM

Yeah. It has the push buttons on the dash. I can shift them in and out of gear. Only trying to start if it says it's in Neutral. I've tried shifting in and out of neutral a few times to get it started.

ewo1 09-23-2019 02:54 PM

I would check the VIM, not sure about your bus, but there should be 6 relays in the VIM. One of them is for the neutral starter safety. Unplug all 6 relays and reseat them.

Also I would try the #1 old school way for getting a stuck starter to spin, bang on it with a hammer while you hit the ignition switch.

Also don't forget to make sure voltage is reaching the solenoid when you turn the key.

Johnny Mullet 09-23-2019 04:04 PM

The starter should have a smaller "signal" wire to it and it should light up when the ignition is in the "Start" position or when starter button is pushed. If it lights, there is an issue with the starter motor. Try whacking it with a hammer like suggested only if the signal wire is getting voltage.

All times are GMT -5. The time now is 11:52 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.