416h Onan wiring gremlin . Won’t crank

[Brian307 4]

Hi gang . I’m pulling my hair out working on a 416 model #73423 serial# 6900310. So the tractor just decided not to crank over . I’ve replaced the battery , positive battery cable , ignition switch , fuses , and relays . I’ve checked the safety switches and grounds and I’ve also pulled apart and cleaned and reconnected just about every plug connector on the tractor .now  The big pin connector on the left rear of the engine does have 2 wires that appear to have been cooked a little bit at some point in time but appear to still be making contact . If I jump the solenoid she cranks right over or if I put juice to the light blue colored wire in said connector but when you turn the key I just get a clicking at the relay . Any help will be appreciated  . Thanks 

[gwest_ca-(File Mod) 11,046]

Welcome to forum.

Download this file. Each circuit has it's own diagram so you can start at the battery and follow the current to each destination with a test light or voltmeter.

 

[Brian307 4]

I’ll take a look , thank you 

[953 nut 55,280]

10 hours ago, Brian307 said:

If I jump the solenoid she cranks right over or if I put juice to the light blue colored wire in said connector but when you turn the key I just get a clicking at the relay

Sounds like you have narrower the problem down to a few components, any one of which could be the culprit. The first thing to check would be the condition of then 25 amp and 30 amp fuse holders, They are subject to corrosion because they are so close to your battery. Be sure the PTO is in the off position.

Put the rear end of the tractor on jack stands so you don't have an unanticipated start take off on you'

Use a DC volt meter or 12 volt test light to check each component in this order. Any one of these parts that doesn't give the expected results should be inspected further.

At the ignition switch do you have battery voltage at the RED battery terminal with the key off? With the key in the start position do you still have voltage at the red battery terminal? 

With the key in the start position do you have voltage at the white wire at the s terminal of the switch and the same white wire at the PTO switch? Presuming power is making it to the PTO switch keeping the key in start is there power coming out of the switch on the Violet wire going to the neutral safety switch? You will probably need to remove the shifter tunnel cover to do this.

With the key in the start position if power is making it to the Neutral safety switch you can close the neutral safety switch to see if power is going from it to the start relay on the dark blue wire. some of these safety neutral switches are mechanically activated and others need a magnet to activate them. 

At this point you should hear the start relay close and the solenoid close activating the starter. If this isn't happening substitute another relay (they are all the same) and try again.

Hope this helps.

Edited April 4, 2023 by 953 nut

[rmaynard 15,501]

Is your motion control on the steering column? There is a neutral safety switch located behind the dash that can sometimes be the culprit.