Can't get M1078 started...

[Spdracr]

I was messing around and was looking at the breakers and saw a starter interrupt button. I pushed it and the truck would not start. Pushed it again and it started. Waited about ten more minutes and would not turn over. Is there some trick that I missed. Looked in operators manual and cant find anything on it. Everything was working fine until I messed with this and now nothing. Wont do that again. Any ideas on what is wrong? I can feel the starter relay hit and juice is good just nothing hitting the starter. Thanks...

 

[Lmtv772]

Turn the Master off ...and on and it will work.
READ THE TM. that's a direct order

 

[Spdracr]

Do you mean the master on the dash? If so have all ready. Do you mean another master switch? Everything clicks like it should just no start.

 

[Lmtv772]

Yes the master switch on the dash. It resets the starter over ride

 

[Spdracr]

Going to go take battery posts off and then back on. See if that resets anything.

 

[Spdracr]

That didn't fix it either. Seems like all the relays are clicking that should be...

 

[Suprman]

Push the button again. It inhibits the fuel solenoid. You can manually put 24v to the fuel solenoid with a clip lead.

 

[Spdracr]

Tried pushing the button multiple times. Even found relay that it powers or doesn't power and switch relay with another relay and still no start. Can even hear something click and unclick under cab when push the interrupt button over and over. Turn off power and cycle again over and over and still not turning over.

 

[NDT]

Is the transmission controller lit up?

 

[Suprman]

Measure make sure you have 12 and 24 volts
at the panel left lugs. Manually open the cab and jump the aux start solenoid drivers side frame rail see if it starts. Have power switch on or it will just crank. Could be a bad relay in the panel or something simple. You could also jump the starter relay take it out and touch a wire top to bottom of the socket.

 

[Spdracr]

Transmission controller is lit up and can feel all the starter relays hitting. Clicking under the cab like the solenoid is hitting but not turning over. Maybe solenoid but I will try what you guys said first.

 

[Suprman]

If the starter solenoid is engaging but not turning over it could be due to weak batteries. Someone else I know had this issue recently.

 

[Lmtv772]

I think it's the button of the starter interrupt ...

 

[Spdracr]

Walked out side after dinner and it turned over. Didn't start. I changed back the horn relay and starter interrupt relay and tried again and it hit and started. Tried three times and still started. Read somewhere maybe a thermal switch on starter relay? Anybody know about this?

 

[Suprman]

Thermal interrupt would prevent cranking. Get some new relays for your panel.

 

[Spdracr]

Where would I get some relays? They are 24v right?

 

[Suprman]

Half 12 and half 24 volt. Standard Bosch style automotive relays. Panel inside should have a diagram showing what's what.

 

[scottmandu]

Jumper the start relay and this will tell you if the starter relay is bad or not. If it starts then it's the relay or the switch or something in between. Also it's critical that battery voltage is above 24V.

 

[Spdracr]

Got it running. Not exactly sure what was causing it. Has been starting fine. Going to get some extra relays and if it happens again, maybe that is it. Thanks...

 

[Ue413]

Spdracr..... I've got same issue truck attempts to start but does not. I can hear start relay clicking and assume is bad. Can you let me know where you picked up relay and associated part number?

thanks!