Electrical issue and question

[Code54]

We have an old mule (1985) that ran good until last night. I pulled the plastic off to clean it all up and when I went to start it today - nothing....
Not a crank, nothing. Thinking it was a loose connection somewhere, I checked them all. Cant find anything. Checked the brake interlock - seems fine. Put a 12v tester on the battery (the simple one with just a light) and nothing - no light. Ok, the battery is dead - pulled it out and put my ATV battery in to start it - nothing. Put the tester on the ATV battery while it was hooked up -nothing. OK, the ATV battery is brand new and just charged up. Took the battery out and tested it - light right up. Hook the Mule cables to it, NOTHING and will no longer light up. Tried to jump start the Mule - smoke - I know that is not good. Found where the fuse blew and replaced it. Still nothing.
I have no idea what could be wrong. The only electrical things I touched removing the plastic was the on/off switch for the front lights and the key switch - both are just plug in harnesses so nothing real tricky. Any idea what is going on and what I need to check? Could the Cdi box have suddenly went? (it basically has a 10HP Kaw. motor )
Thanks for any ideas as Im stumped

 

[Code54]

Not sure if I wrote that clear, but when the Mule's battery cables are hooked to the battery I can't get the tester to even light. Never had this happen and seeing I couldn't find a bad safety switch (not many in 1985) I'm really stumped

 

[Johnny g]

Are you putting the test light on the battery terminals or on the cable ends attached to the battery? maybe corroded cable ends?

 

[timswi]

First guess is that the main ground is bad...Try manually grounding the battery and re-test.

 

[Code54]

Thank you both.

I was putting the light on the screws of the battery. But no light????

By manually grounding it I am gassing you mean run a wire from the neg straight to the frame?

The part I just can't understand is it worked fine 24hrs before and I never messed with the battery/electrical - just took the switch out of the plastic.

 

[timswi]

Thank you both.

I was putting the light on the screws of the battery. But no light????

By manually grounding it I am gassing you mean run a wire from the neg straight to the frame?

The part I just can't understand is it worked fine 24hrs before and I never messed with the battery/electrical - just took the switch out of the plastic.

Yup, just clean up a place on the frame and temp ground it to see it that's the cause..I like cleaning my stuff like that too, but sometimes it creates more problems than it solves..The most reliable used vehicles I've ever bought had the beejeebers beaten out of them. The most un-reliable, the ones that were over maintained..Why?--I can't say.

I take care of my stuff anyway..

 

[Scrambler82]

Did you say you rechecked the connection on the key switch ?
The battery should show full voltage if you test across the poles !
Is there anything like a battery minder in the circuit ?

Test light should be positive to frame.

Take a continuity tester, and check the cables from end to end.

Why it worked 24 hours ago and not now is a hard question to answer, you need to review all of the connections you played with. If there are connectors you need to check the pins on both ends, some may have unlocked and slips and/or some may be broken.
Not a lot could change in the time frame you are stating other than something going wrong with what you touched.

Luck on your search.

 

[mjw357]

Is this a side post type battery? The fact that a fully charged battery will not even light a test light tells me you aren't getting a good connection with the cables.

 

[timswi]

One more thing--I've had ground cables rot out and separate under the insulating cover..Just FYI.

 

[Scrambler82]

Is this a side post type battery? The fact that a fully charged battery will not even light a test light tells me you aren't getting a good connection with the cables.

Sometimes the strip connecting the side posts are weak and break or burn up... but you did say you used another battery to check.