I Messed Up…

[Horse Newbie 7,159]

I had to get to my yard trailer I pull behind my tractors.

To do that I have to move all tractors since the yard trailer is seldom used(2-3 times a year).

One tractor would not crank over even though it is kept on a battery tender.

Well I was gonna jump that tractor with my 1994 520H which was parked right beside the one that was dead.

I hooked the jumper cables up wrong( cross-crossed) and got a big spark.

Snatched them off… actually they were never really hooked up because of the fireworks show…

Hooked them up right and jumped the dead tractor.

While I was waiting for the battery to charge( less than a minute) I noticed the volt meter on the 520H was right at 12v or a hair below. I will consider this normal since I had jumper cables on there. 
When the dead tractor cranked and I took off the cables, the volt meter went up to about 14v/ normal.

Both tractors ran fine after that and the 520H was showing 14 v the whole time it was running. 
What are the chances I may have harmed something on one or both of my tractors, and if so what would likely have been affected or zapped ?

[adsm08 2,214]

If everything starts, runs, and charges you are probably OK.

 

These tractors don't have the advanced electronics that vehicles have that are usually what takes a hit from events like that. Just check any fuses that they both may have, maybe put a voltmeter set to AC on each battery with the engine running and make sure the reading isn't above .03.

[953 nut 56,091]

Only thing injured was your ego.

[Horse Newbie 7,159]

11 minutes ago, adsm08 said:

Just check any fuses that they both may have, maybe put a voltmeter set to AC on each battery with the engine running and make sure the reading isn't above .03

I didn’t know I could touch the leads from a volt meter to the DC posts on a battery when the tester was set on AC… I thought that would zap my volt meter….

[Horse Newbie 7,159]

8 minutes ago, 953 nut said:

Only thing injured was your ego.

And the threads on the bolts that hold the battery cable clamps tight…

I will most likely have to install new bolts when I ever take the clamps off the posts…

[adsm08 2,214]

2 minutes ago, Horse Newbie said:

I didn’t know I could touch the leads from a volt meter to the DC posts on a battery when the tester was set on AC… I thought that would zap my volt meter….

 

No, it will measure the AC voltage there. If you check just a battery you should be a zero reading. The generator on that engine should produce an AC voltage, which is turned into DC by running it through diodes. The test I gave you will check the integrity of the diodes. A 3-phase unit should allow not more than .03 volts bleed-through, .01 for each diode.

 

Hooking the meter to an AC source on a DC setting can cause damage, depending on the quality of the meter.

 

Hook the meter to ANY voltage source while the probes are in the mA configuration will cause damage. I managed to burn a trace off the board in my one.

[SylvanLakeWH 26,101]

Good thing none of us  have ever accidentally tried welding with jumper cables... 

 

[kpinnc 12,743]

39 minutes ago, Horse Newbie said:

I thought that would zap my volt meter….

Only thing that might do that is if you check resistance over an energized circuit. 

Edited December 8, 2024 by kpinnc

[Horse Newbie 7,159]

47 minutes ago, adsm08 said:

 

No, it will measure the AC voltage there. If you check just a battery you should be a zero reading. The generator on that engine should produce an AC voltage, which is turned into DC by running it through diodes. The test I gave you will check the integrity of the diodes. A 3-phase unit should allow not more than .03 volts bleed-through, .01 for each diode.

 

Hooking the meter to an AC source on a DC setting can cause damage, depending on the quality of the meter.

 

Hook the meter to ANY voltage source while the probes are in the mA configuration will cause damage. I managed to burn a trace off the board in my one.

Thank you kindly sir for that information.

I understand basic house wiring and simple circuits to a degree, but you start throwing in diodes, amps, ohms, controls, switches, and such and my mind struggles. 

[Horse Newbie 7,159]

20 minutes ago, SylvanLakeWH said:

Good thing none of us  have ever accidentally tried welding with jumper cables... 

 

I’m a trailblazer !

[Horse Newbie 7,159]

18 minutes ago, kpinnc said:

Only thing that might do that is if you check resistance over an energized circuit. 

I can do it ! I have the ability !

[adsm08 2,214]

4 minutes ago, Horse Newbie said:

Thank you kindly sir for that information.

I understand basic house wiring and simple circuits to a degree, but you start throwing in diodes, amps, ohms, controls, switches, and such and my mind struggles. 

 

I have known a lot of people over my career that really struggled with electrical. It's one of those things, you get it or you don't, and there is not really any middle ground.

[kpinnc 12,743]

3 minutes ago, Horse Newbie said:

I can do it ! I have the ability !

 
At least once, or until you run out of meters! 

[adsm08 2,214]

22 minutes ago, kpinnc said:

Only thing that might do that is if you check resistance over an energized circuit. 

 

Actually, that doesn't really do anything except return an incorrect reading.

 

Resistance measurements aren't direct, they are inferred. The meter puts a tiny bit of voltage out and looks to see how much it gets back on the other end. That's how it can use the same port for voltage and resistance.

[Treepep 591]

11 hours ago, SylvanLakeWH said:

Good thing none of us  have ever accidentally tried welding with jumper cables... 

 

First car ever died at the local gas station... Old timer that owned it jumped it bass awkward and melted the positive post.  I got a new battery that day for free but The lesson was you have to watch EVERYONE.  Even really bright folks step in it sometimes  Glad you are fine.  Horsey can be fixed relatively easily.  

[Racinbob 11,278]

[Horse Newbie 7,159]

1 hour ago, Racinbob said:

Those unexpected fireworks made me jump for sure…

[Kenneth R Cluley 535]

Hopefully like I always say " Nothing a new pair of underware won't fix"!

[c-series don 9,005]

22 hours ago, Horse Newbie said:

Thank you kindly sir for that information.

I understand basic house wiring and simple circuits to a degree, but you start throwing in diodes, amps, ohms, controls, switches, and such and my mind struggles. 

I’m in the same boat, I kinda get it but sometimes I’m left scratching my head. I’m sure if I had a good teacher and I did it more often I’d be much better at it.