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Discussion Starter · #1 ·
Welding w/ Battery connected, now it won\'t start

I know you are supposed to remove the negative battery cable before welding. I thought I left it off from the last time I was welding, but I didn't and I didn't check until I was done.

Basically, I was welding for about an hour put patch panels in the floor. Afterwards the CJ wouldn't start. Did I kill the battery (Optima Yellow)? The CJ started on Sunday, and I haven't had a problem starting at all even after sitting for a month.

I also heard some ticking under the dash, it was too dark for me to see anything, but I think it sounded like it was in the fuse box area. I disconnected the negative cable and called it a night. I didn't try to jump it yet.

Thanks for the help.

Mark F

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

Check your battery cables and your ground.
Welding current will find any weak connections.

With everything hooked up...
Take a 16 Ga. wire (or larger) and connect one end to the positive side of the battery, and the other to the small terminal on the starter solenoid marked 'S'.
Be prepared for the engine to crank! Have it out of gear and the E-brake set.

If the engine cranks, it's not the battery, battery cables starter solenoid or your starter.

Check to see if you have power to the wire that's supposed to hook up the 'S' terminal when the key switch is turned to 'Start'.
You can use a light or a buzzer with one side plugged into the wire, and the other grounded if you are working alone.

If you don't, check fusible links and fuses.

Get back here with the results and we'll go from there.

So many cats, so few recipes...
 
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Discussion Starter · #3 ·
Re: Welding w/ Battery connected, now it won\'t start

Thanks TR. I'll have to wait till Sunday before I have to time to try that out.

My question is a) should I bother trying to boost/jump it, before going through your suggestions? and b) Any thoughts about the ticking/clicking under the dash by the fuse panel?

Thanks again
Mark F

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

You can try jumping it, but that won't find your problem, just bypass the symptom.

So many cats, so few recipes...
 
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Discussion Starter · #5 ·
Re: Welding w/ Battery connected, now it won\'t start

I know you're right, I guess I'm asking if it is dangerous to try to jump it, or if it will make it worse

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

Jumping it won't hurt anything that isn't already hurt, as long as you jump it properly.

Your problem is almost certainly a ground connection between where your welder ground was attached and your work area.

In future welding projects, remember to connect your welder ground as closely as possible to your work area. What causes the problem is having the ground at one end of the frame and welding the body somewhere else. The welding current has to go through several joints and connections to get back to the source. In an old vehicle those joints can fail and force the current to take a different path.
 

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Re: Welding w/ Battery connected, now it won\'t start

Jumping it won't hurt anything that isn't already hurt, as long as you jump it properly.

Your problem is almost certainly a ground connection between where your welder ground was attached and your work area.

In future welding projects, remember to connect your welder ground as closely as possible to your work area. What causes the problem is having the ground at one end of the frame and welding the body somewhere else. The welding current has to go through several joints and connections to get back to the source. In an old vehicle those joints can fail and force the current to take a different path.
 
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Discussion Starter · #8 ·
Re: Welding w/ Battery connected, now it won\'t start

TR, this is the thing. The welding ground clamp was lying on the patch panel. In otherwords there was no more than 4" between my ground and my welds.

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

It doesn't matter...
If you were welding with reverse polarity, the introduction of high amperage and/or voltage current to the vehicle ground may have nuked the diodes in the alternator, and the alternator is sucking your battery dry.

You may have 'Hot Charged' the battery with AC or DC voltage... Hot charged it to death...

You may have started to nuke the battery, or some other component, but the bad ground let go and saved the components...

It may just be a coincidence that the problem showed it's self now...

You won't know until you charge and load test the battery, and jump over the solenoid...
If it starts once, and won't start in the morning, start looking VERY closely at your battery and alternator.
Both should ALWAYS BE UNHOOKED BEFORE WELDING ON ANYTHING!

BTW?
What kind of welding were you doing, ?
MIG, TIG, Stick?
Electrode positive or negative?
Stick welders are notoriously hard on batteries, and MIG welders are notoriously hard on alternator rectifiers...

So many cats, so few recipes...
 
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Discussion Starter · #10 ·
Re: Welding w/ Battery connected, now it won\'t start

Thanks TR, if the weather is bearable I'll start playing with ti tomorrow morning.

I was doing MIG welding, on the areas under the rollbars front feet behind the driver's seat. The ground clamp was on the panel itself. My gut is a combo of what you said, possible bad/weak battery and some grounding issue. I never started the CJ after I welded so I'm not sure if the alternator had a chance to kill the battery. When the battery was connected and showing 10 volts on he dash guage, even without the key I was able to hear some clicking going on. I disconnected the battery and called it a night. I'll double check the fuses and the wires in the area where the clicking was coming from. Then I'll jump the CJ as you suggested and go from there. I'll report back.

Thanks again for the help.

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

You know TR, thats something that I had never heard. In all the stuff I have read in hear noone ever mentioned it. I guess I have been lucky up to now, the couple of times I have welded something on to the jeep, I didn't fry anything. but it makes sence and I will defently start unhooking those two components before I weld.
That should be Listed on that list you were going to create for the TR website as item no. 1

surveyboy

http://www.csupomona.edu/~sdmiller1/jeep.htm
 

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Re: Welding w/ Battery connected, now it won\'t start

NOPE!
Proper eye protection is always First and Formost...
Not just your day is over, or you need a few replacment parts, if you have a serious eye injury your LIFE is over as you know it...

It's hard to wheel,.... or look at Playboys..... or anything else when you are blind...

So many cats, so few recipes...
 
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Discussion Starter · #13 ·
Re: Welding w/ Battery connected, now it won\'t start

TR, Thanks again for the help. I think I got away lucky. I went out and tested my battery 10 volts. I connected the battery anyway and of course it wouldn't start (only 10 volts). However, I was able to track down the source of the clicking. I bought the CJ a year ago, apparantly there is an alarm that has been left unarmed since before I got it, so I had no idea it was there. When I reconnected the battery the alarm brain was making the clicking sound. I must have grounded out or shorted the alarm brain, because even after I attached the booster cables from a running car it wouldn't start due the alarm relay on the starter circuit. After performing a quick labotemy and removing the alarm, the CJ fired right up. Needless to say, I finished the rest of my welding with both the positive and negative cables disconnected. Reconnected the battery and it fired up again. The real test will be tomorrow night after sitting for 24+ hours.

Hopefully I was lucky and didn't kill the battery or alternator.

Thanks again for the help

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 

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Re: Welding w/ Battery connected, now it won\'t start

The thought of a previously installed alarm getting fried during welding would have driven me crazy for DAYS!!!! /wwwthreads_images/icons/mad.gif

Glad to hear you are up and running!

So many cats, so few recipes...
 
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Discussion Starter · #16 ·
Re: Welding w/ Battery connected, now it won\'t start

Well I'm real lucky I even found it. I got up under the dash hearing this cliking noise. The CJ is showing 14 Volts on the dash guage cause I have jumper cables from a running car. Nothing. But I hear this clicking, so I start checking the big fuses, blinker wiper I move some wires it stops starts again, then I look to see where the wires are going and there is this box way up behind the vent tubes with a flashing red light. That's when I started to be relieved and I was hoping that was the problem. I pulled it down and it was an alarm (I forget the brand), bypassed it and bingo it started.

I hope 2 things were happening 1) the alarm was doing enough to drain the battery, there is no speaker and 2) the starter cutoff was preventing the starting.

I'll find out tomorrow night.

Thanks again all!

Mark F

1986 CJ7, Chevy 350, D44/D30, more to come shortly
 
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