Short where do I turn

[tennessee toy]

New battery. Started right up. Cut it off and now it is one click and no power. I can disconnect battery, hook it back up and I have lights and power. Go to start it and clicks once and lose everything again. Any advise on chasing this - what seems to be a grounding short to me?

 

[Brush Hog]

Check ground wire on negative side. Mine got frayed looked like it was connected but caused similar problems. And it happened after removing and reinstalling the battery. Figured it out after having it towed home.

 

[Golfball]

Yes, clean all of your main connections and also check the voltage at the battery. You can have lights and such at 10 to 11 volts but that isn't enough to engage the starter/solenoid.

 

[Wes harden]

Also check that the connections at the fender mounted solenoid are tight and clean. Check at the starter itself, look for melty cable insulation and tightness at the starter lug. Make sure cable hasn't shorted to exhaust manifold.

 

[DirtDonk]

All of the above.
Plus it could be a bad/failed battery cable. Either the positive or negative side, but not always visible.
In my case it was the short positive side, and I've seen it two other times on other rigs.

It likely is not the ground to the body. The starter relay/solenoid would be effected by that, but not the other stuff. You would not have a 1-click and nothing scenario I would not think.

How old are the main cables, and what condition are they in visually?

Paul

 

[Rustytruck]

First place to check is the alternator and voltage regulator. Charge your battery. them hook it back up. start your truck and check the running voltage. while running it should be close to 13 volts. cut the engine and check the battery voltage an hour later. disconnect the alternator and voltage regulator. mow let the battery sit all connected for the next 3 days. check the battery voltage every morning should not loose voltage with the alternator and voltage regulator disconnected. if battery is still using voltage you either have a short or some parasitic battery drain. like the memory from an aftermarket radio a tachometer or the ignition switch.left on. with the key off check for voltage at the coil, their should be none. when disconnecting the alternator remember the wires are still hooked to the battery and are live take all precautions. Brake lights and brake light switch are live so a fault there is a common drain spot. as are head lights.

 

[4xfun]

It sounds like may you have a self resetting circuit breaker in the system. Has the wiring been modified (highly likely)? Has the wiring been upgraded to a newer wiring system? You may have to start pulling fuses and unhooking wires to isolate the issue. It sounds like it might be related to the starting system. you may want to unhook the starter and see what happens when you turn the key. If you can turn on the lights afterwards, you may have found the issue.

Several people make a circuit tester and tracer wire short circuit finder. It can help find a short in a wire that is covered in tape or is hidden in a loom.

 

[DirtDonk]

And while you're at all this digging around, take some pictures under the hood for us to look at too.

Thanks

paul

 

[sprdv1]

All of the above.
Plus it could be a bad/failed battery cable. Either the positive or negative side, but not always visible.
In my case it was the short positive side, and I've seen it two other times on other rigs.

Concur.. Just take your time, keep tracing out the issue *always something w/these things

 

[1970 Palmer]

Several people make a circuit tester and tracer wire short circuit finder. It can help find a short in a wire that is covered in tape or is hidden in a loom.

This can be a very helpful tool, if you know how to use it.

It can be as simple as a test light bulb with two alligator clips. Connect one clip to the battery positive terminal, and the other clip to the disconnected supply wire. If the bulb lights you have something turned on draining the battery. Remove fuses, disconnect/re-connect switches until you find the one that turns off the bulb and you have narrowed the problem down to the circuit in question.

 

[tennessee toy]

Thanks for all the replies. As always, this group is second to none! Been crazy busy, replacing starter cable in the morning as it has a fray - will give feedback. Thanks again!

 

[Ecavalino]

Hey had similar problem recently .. mines a ‘74 and turned out the starter relay crapped out. Changed it and new starter (302 manual specific) and voila … like a charm all good now. Hope it’s an easy fix for ya!


Sent from my iPhone using Tapatalk

 

[cldonley]

Always check the simplest, cheapest thing first. Terminals for corrosion and security. Starter relay for proper operation. As said above, 10 volts will turn on the lights but won't turn the starter. I've had a battery cable (on an airplane, but same thing with a 12 volt system) have a ground cable that showed continuity but wouldn't hold a load due to internal corrosion. Check the cables first!

 

[tennessee toy]

Replaced cables! Same scenario. 1 click and lose everything. Disconnected starter - one click but DID NOT lose lights. Replace starter?

 

[DirtDonk]

You replaced both battery cables? Positive and negative?
That’s interesting.

Yes, the starter could be at fault here for not cranking. But the starter can’t cause a power loss anywhere else.
Just doesn’t work that way.

The only other thing I can think of is if your fusible link on the black wire is being overloaded slightly because it’s partially melted already.
Not sure how to check that though. Anybody know if there’s a voltage drop test that can be performed on the black power wire?

 

[Wes harden]

Sounds like a bad connection at the solenoid. If the smaller wires connected to the battery side of the solenoid looked melty, pull on them if they stretch then the fuse links are bad.

 

[Steve83]

No, do NOT replace any more parts until you KNOW what the problem is. And it's not a "short" (which blows fuses &/or sets things on fire); it's an "open circuit" (which turns things off).

Re-connect the starter as normal, and clean some test points on the battery posts & clamps to shiny metal. Open the hood & doors so you don't have to disturb anything, and then try to start. When it clicks & power is lost everywhere, DON'T DISTURB the truck any more than necessary - not even slamming a door. Get your digital multimeter set to DC Volts (solid line above dashed line), make sure the meter has good batteries, and then start measuring voltage across the battery POSTS (not the clamps around the posts). It should be ~12.5~13.5 VDC. If so, move ONE of the probes at a time onto the clamp around the post, noting the voltage - it should be exactly the same. If so, move the other to its clamp. Continue moving ONE probe at a time across ONE connection at a time (from the clamp to the cable; from the cable to its ring terminal; from the ring terminal to the bolt; from the bolt to whatever it's bolted to...) working your way toward the dash fuse block, using the body tub as ground.

At some point along that path, voltage will drop to or near zero. When you see that, move the last probe back half as far as you just moved it, trying to pinpoint the physical location where voltage changes - that's the problem. Disassemble, clean, & repair it. Post pics.

 

[triracer67]

Had similar issue years ago. Mine turned out to be VR. Kind of stunk because it killed battery dead. I always carry spare solenoid, VR, and points. Seems like these are common failing points…I did discover by isolating electrical components as mentioned above.

 

[tennessee toy]

Late response. Donk - sorry - at this point I have changed cable to starter - starter tested good, I have replaced starter solenoid. Visually have looked at everything and crawled on, under, over, etc. Unfortunately, ditto - same thing happens. I replaced the steering column a while back and those wires were a pita but can figure this would have anything to do with scenario I have. I HATE electrical issues

 

[DirtDonk]

at this point I have changed cable to starter - starter tested good,

What about the two main battery cables that we are talking about?
It’s always good to have a nice new relay to starter cable, but it has absolutely zero to do with losing power to the vehicle.

have replaced starter solenoid.

Here again, absolutely zero to do with loss of power to the vehicle.
It can keep the starter from cranking, but it can’t kill power to the rest of the vehicle.

Visually have looked at everything and crawled on, under, over, etc. Unfortunately, ditto - same thing happens.

But did you replace the two main battery cables with new?

replaced the steering column a while back and those wires were a pita but can figure this would have anything to do with scenario I have.

Correct. Absolutely nothing to do with losing power to the vehicle.
Unless while changing the column you accidentally messed with the large black and yellow wire that supplies power to the vehicle.