Why did I get Shocked

I was working on my 1952 chevy 3100 pickup truck tonight. I had my forearms on the fender and reached in the engine compartment and grabbed the carb to adjust the linkage. Just as I was touching the linkage I felt a good shock of a electricity. After thinking something was wrong I took the negative lead off the battery in hopes to kill the engine (forgot to tell you the engine was running when i was shocked). To my surprise it did not stop running.

So a couple of questions.

Could this be a positive ground vehicle
even if it was a positive ground vehicle should i have been shocked
or do i need to look for a short to ground
finally shouldn't the motor have died when i pulled off the negative lead.

Thanks for your help

 

you can actually change batteries with the engine running, I don't think that was your ptoblem

 

interesting. I though by removing a battery lead you would brake the loop. Thus no juice to fire the motor. See that is what the HAMB is all about, a little education

 

Hi mj, yeah I believe it is positive ground in stock configuration.

It's good that your engine kept running when you disconnected the battery-cable...shows your charging-system is working.

I'm thinkin' you got shocked because one of the spark-plug wires is touching something. Turn the lights out, run the engine, and look for arcing. Fix that, and it might run a little better too. Good luck.

 

re-ground your truck....seems like you became the ground and got the tickler as a result.

 

I think this is your answer.
Check for poor ground between the engine, frame and body.

 

Im going with the one previously posted twice..

Sounds like a bad ground.

 

Chevy 3100's are negative ground - GMC's were positive ground from the 30's through 55 second series.

You need to check the ground from the bellhousing by the starter to the frame. If it is missing or corroded - you could get a lively shock.

 

As has been said, check to make sure the ground straps are all in place.
Electricity takes the path of least resistance. It was probably flowing through a bad contact, rust, whatever, and when you laid your arm on the fender and touched the carb (engine ***embly), you became the path of least resistance.

I believe most engines have at least two ground straps: one to the ch***is, and one to the firewall. Some have more than that.

There should also be a ground from the body to the ch***is.

As for why it continued running with the battery cable off--that's what an alternator does: it keeps the engine running.

-Brad

 

actually, by disconnecting the battery thats how you test the generator lol if it stays running its putting out the proper voltage for the most part. you got a shock because you were most likely sweating and it had a bad connection.

 

Exactly...same with an alternator...if you remove the battery cable(s) and the engine stays running...the alternator is doing its job...

Your shock is a result of a bad connection somewhere...

R-

 

UMMM, your getting a shock from 12 VOLTS??? I don't think so, don't believe me,take your left hand and grab the negative terminal of the battery, grab the positive terminal with the right, do you feel all that 12 volts cursing through your body, NOT.

The engine was running!, most likely one of your spark plug wires are cracked, thus the jolt of electricity. Check your plug wires for cracks and shorts. Most likely one of the wires is in contact with the linkage or close to the linkage and when you touched it, you completed a short circuit.

 

hes right! maybe you touched the coil? ive done that before! didnt hurt. just woke me right up!

 

Had this happen to me, definitely FM

 

Probably run into the ground by now but I believe your problem is a lack of ground. HRP

 

#### Bingo !! And you need to get the engine grounded to the ch***is and the firewall grounded to the ch***is and the engine grounded to the firewall. The last thing you want is the carb linkage to be the grounding link between the engine and the firewall >>>>.

 

Yep, my thoughts exactly before I read their answers. Run a ground strap from the engine to the body and one to the frame. When you got shocked it was because you had become the easier path for electricity to go between the body (fender) and engine and completed the circuit.

 

now take a wrench and hold it while you touch both sides of the battery, let us know how that works out for you when you get back from the hospital, father-in-law almost lost his finger when his wedding ring started burning to the bone.

i'll toss out another vote for poor ground for the problem

 

My point is 12 volts is not enough to feel, Must have been voltage from the coil! So engine to body ground doesn't matter unless the coil is body mounted.There are 2 different circuits in the motor bay, 12 volt which in 99% of cases you cannot feel and the high voltage from the coil, which will knock you on your *** if your not careful.

 

^^^^^ I'm with Jr on this one. 12 or 6(on a truck this old) volts DC will not shock you but 40,000 fron the ing. system will give you a jolt. Spark plug wire, for shure.

 

Your point is wrong. Nice hot day, sweat flowing, reach into variuos locations of the car with a wet t-shirt leaning across the fender and you'll get a buzz. And you don't even have to have the car running. Especially if you come into direct contact with the + battery cable !! >>>>.

 

Ive been tickled with 12 volts several times on a hot sweaty day. I vote for bad grounds also.

 

jrblack30 is right

 

If you were really hot and sweaty, maybe the 12v could have shocked you.

But I would guess it's more likely the ignition that somehow got you.

 

Try the same thing with the engine off, shock or no shock?? I bet no shock.

 

It isn't the voltage, it's the current (amperage) that shocked you. It can certainly come from a 12-volt source. Agreed on the posts re the grounds; make sure the ground straps are in good shape and their connectors nice and clean. Ditto where they connect to the ch***is and BODY.....the body needs to be grounded as well as the ch***is. Remember that the body sits on rubber isolators, so simply grounding the ch***is does not get you a grounded body. Make sure the body includes a ground strap to the engine block or some other path to the negative side of the battery.

 

obviously JRBlack And snow man havent been shocked by a 12 volt battery before but you can be shocked by one. its not the intens shock you get from a sparkplug wire but it will definitly get your attention. its more like a tingaling but it can make you jump if it touches the right part of the body.I leaned into an engine compartment with the sweaty shirt method touching the battery and my arm on the valve cover.and bzzzzzz.it got me. in fact if any you fellas dont belive me I can still show you on my ford ranger. send me an email i'll give you my address and I'll let you try it out.lol

 

hahahahaha! yea its a bad ground, but i have been coil bit before! and i have the tingle of a loose ground,ground everything and you should be ok!

 

It seems to me that a bad engine ground could cause you to get a shock from the ing. system even if its not arcing... That 10k Volts has to go somewhere after it arcs across the plug, right?

I've also heard disconnecting the battery with the engine running is not a good idea, it will put the alternator into full field (full charge) and without a battery in the system it can burn up some of the higher output alts pretty quick...

 

Thanks for all the replies. Shocked was a strong word, it was more of a good buzz. I will be checking and redoing the ground straps this weekend. thanks. And now I know that my generator works