L3200 dead... electrical gremlin

[Fallon]

Doing some field mowing for somebody & shut things down for the night running fine. Come back today & it won't start. Thought I heard a click when I turned the key, so assumed dead battery. Ran home to get the jump pack, nada. No cranking, no lights, no nothing. All of the big 30-40@ fuses seem to have 12v at them, but the small fuse block only seems to have 3-5v. Tore the dash apart to get to the ignition as it felt a little weird (could easily just be me imagining things). Got 2 ohms of resistance across some likely seeming wires there, but didn't have my workshop manual with me.

Came back home & am looking my workshop manual again. When I head back I can re-check the ignition switch against the manual. I'm trying to figure out if there is any relay between the fuse box & the ignition switch, but having a hard time with the wiring diagram. Does the key stop solenoid relay also act as a relay for the fuse box? If so, where is it?

 

[k0ua]

The first thing I would check is the procedure in the WSM on page 298 on the pdf or page 9-s7 in the paper manual. This is the test to see if the battery connections are good by taking a voltage measurement between the post and the connector. No more than .1 volt across them. Then move on to the key switch tests on page 300 of the pdf or 9-s9 of the paper manual.. lets go from there.. The "wiring diagram" sucks. Unfortunately it is NOT an electrical schematic, just more or less a block diagram, and I am not use to following such a diagram. But we can work on it later as time permits. But I would perform those checks first and go from there.. I suspect the key switch.

 

[Tomtint]

My L3700 did the same thing. It was the small wire in the back /side of the starter.

 

[JerryK]

Not saying this is your problem... but probably in excess of 90% of starting problems like yours are either battery or battery cable related. With probably the large part of that battery cable related. Battery cables can fail internally because of the corrosive gasses present at the battery. The lead post connector that is swagged onto the end of the wire to connect to the battery post can fail where it may be physically still connected, but fail to pass the large current needed to turn the starter. Any poor connection on the ground wire or positive wire will also cause it to not pass the large starting current. Whenever a person gets the click with no start problem, they should check for voltage from the frame to the starter lug while they try to turn the starter over. If the voltage drops to zero, then test from frame to battery ground post while try to turn it over, then from starter lug to positive post. Worth a try...

 

[ritschner]

After rereading your post I decided to rewrite mine to suggest checking the battery cables as suggested by JerryK. Ran across a situation last week where the battery was showing 12.6v and the car would crank but not start. A diagnostic check showed only 10.4v at the PCM. It was the first time I have seen an issue like that one where the vehicle would actually crank and not start due to low voltage. Twisted and tightened the negative cable and issue was resolved.

 

[Mike from MI]

Had same problem with my l3200. Checked battery cables they seemed tight but I removed ground cable to chassis cleaned cable and chassis re tighten, fired right up with no issues since.

 

[Fallon]

Battery & cable issues were my first thought too. Everything seems good & my jump box changed nothing.

I got 12.5v or so at all the 30 & 40 amp fuses, but only a couple of volts at the small fuse block. Which made me start think master switch or relay. But I didn't have the WSM with me (thought it was just a dead battery & grabbed the jump box, didn't want to make a 3rd trip for the WSM by then) to properly check the master switch.

The free Harbor Freight multimeter was telling me there was a few ohms of resistance across a few of the wires for the master switch. WSM says anything but 0 is bad. An ohm or 2 shouldn't be to problematic though. At any rate I'll redo the tests & compare to the WSM tonight if it's not raining. Hoping it's just the switch, so I can figure out how to hot wire it & get it on the trailer to get home.

 

[k0ua]

Fallon, squirt some WD40 in the key switch and see if that will get it home. And if it does, you will know that to replace.

 

[Fallon]

Put a can onto of my tools, wire, connectors, switches & WSM this morning. Can of electrical contact cleaner too. Weather is looking miserable & we are going camping this weekend, so may or may not have a chance to rescue it before next week here tonight.