Hey guys im new here and have a problem that i have never even heard of happening. Basically i have been building a 1984 k5 and got it to the point that i felt it could handle some off road fun. Took it through some mud in 4low and did awesome, dropped it back into 2 wheel drive and backed up to disengage 4low and decided to go again, threw it in neutral and before i could even shift the transfer case it shut down on me power and all. I got no power to anything in the truck not even hazards. Got it towed back to my shop and ill be dammed if the frame of the truck is showing 12 volts on a power probe. I even double checked on grounded wires, valve cover, and other possible locations that should be shown as ground (even band clamps and the coolent hose its self is showing 12 volts) i tested the battery with a load tester and its good. Had the altinator tested and that was good. I couldnt find any brake in the wires to show exposed power shorting to ground. No fuses are blown theres no arcing anywhere and no burnt or melted wires. What the hell happend???
CK5
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12 volts to frame?!?!
- Thread starter 84bigblue
- Start date
evolve991
Resident Problem Child
Check for an inline fuse on a wire connected to the junction on the firewall. Mine blew that fuse 3 or 4 times ( never had in 10 years owning it) over 3 days, I found a few bare wires under my dash and rewired the mains to starter,no more blown fuses but now it's showing a drop in voltage with headlights/heater etc and the wiper switch turns on my dash lights.....
Sorry,I hadn't noticed your 'no fuses blown' before typing all this...not enuf coffee....but that fuse isn't in the typical place so.......
Sorry,I hadn't noticed your 'no fuses blown' before typing all this...not enuf coffee....but that fuse isn't in the typical place so.......
Heh coffee is importent! But yea i didnt check for a fuse back there although i didnt see any back there ether when i was checking wires haha, ill have to give it another look see, i still dont understand how the whole truck can be hot without blowing something
evolve991
Resident Problem Child
LOL on my 2nd cup 
OK...the fuse may be tough to find,mine is in a rubber block with a flip lid,it was hard to see. Yes the solenoid may be shorting and conducting,maybe some water got inside?
OK...the fuse may be tough to find,mine is in a rubber block with a flip lid,it was hard to see. Yes the solenoid may be shorting and conducting,maybe some water got inside?Might be worth pulling it off to get it tested then i suppose, the mud was pretty deep (at least the the bottom of my doors) with about an inch or two of water on top so i suppose its a plossible possibility ill have to get back to you on the fuse as i still havnt had my coffee yetLOL on my 2nd cup
evolve991
Resident Problem Child
I wish you luck BigBlue. I'm in the same wiring nightmare as you pretty much
Maybe try a process of elimination approach.....Disconnect the starter and see if it changes. Think of things that don't have fuses like winches and disconnect them one at a time. If nothing changes, start pulling fusses one by one.
As far as the starter goes i did take that approach and disconected my altinator from my starter, (runs to the same post as power to starter) and it stopped giving my 12 volts on the frame however. And this is where it still gets a little weird the only thing i have hooked up other then an aftermarket radio right now is an electric fuel pump that runs to a switch in dash and the switch runs straight to power on the battery with an inline fuse between. Even with the altinator disconected and no longer reading 12 volts on frame i still cant get power to that switch and the pump. I also tried pulling fuses one at a time, i did find one, the stop/hazards fuse. Now it gets a little bit weirder here. With the key in the off position pulling that fuse toom me from 12 volts to 3 volts. Turn the key on and it goes back from 3 to 12. Turn the key off and disconnect the negative battery terminal and it goes from 3 to 11. I also found that if i disconect the wire plug clip thing out of the altinator it takes that voltage from 3 to 0 with the key off. Thats what made me decide to pull the altinator to test it. Now after i had put the altinator back on i just get straight 12 volts again no matter what
The 12 volts would be relative to ground i suppose as that is what the frame and things should be. The power probe is i nifty little tool that hooks up to the positive and negative post of the the batter to supply its own internal power. With this you can apply power (12volts) to what ever you want. You can also apply a ground current to what ever you may need to apply it to. Now instead of having two test leads you just have one probe that you can touch to a ground and will show you 0.0 volts and you touch to a power connection and you will get how ever many volts are running through there. But in my case i am having everything reading at 12 volts. The only place that reads as a ground (0.0 volts) is where the negative cable comes off the battery
So then you lost the ground connection at the other end of the negative cable?
I am wondering if the nifty tool is over complicating this.....
A multi-meter set on ohms has helped me well in situations such as this.
You would be looking for a minimum ohm reading throughout the ground circuit, the negative cable to the engine and also the body.
I am wondering if the nifty tool is over complicating this.....
A multi-meter set on ohms has helped me well in situations such as this.
You would be looking for a minimum ohm reading throughout the ground circuit, the negative cable to the engine and also the body.
I guess i might have explained that wrong what i ment was that you test for ground where the negative cable comes off the battery to the frame. And you will get ground there but every where else is set at 12 volts
Something isn't right. Melting wires or a blown up battery would happen...instantaneously. Use a dedicated multimeter. Can you post a pic of this probe? I'm curious.
Thats the part im very confused about is how i cant find any damage to the wires or battery haha and ill post a pic when i get back to the shop for my next shift =]
I don't own a power probe, although I have used one from time to time. They are neat and can really help troubleshoot problems. However, they do require some thought when using them.
Since I work on stuff from 12 volt auto, to 240 volt multiphase, all the way up to 20 GHz RF, I tend to stick with a good multimeter and specialty stuff.
I think I might know what your problem is. Its a little unusual, and the power probe is confusing the issue.
Do you have a regular voltmeter? If so, connect it from the negative terminal of the battery and then touch the other lead to the frame.
If you get 12 volts, then you have found the problem.
Since I work on stuff from 12 volt auto, to 240 volt multiphase, all the way up to 20 GHz RF, I tend to stick with a good multimeter and specialty stuff.
I think I might know what your problem is. Its a little unusual, and the power probe is confusing the issue.
Do you have a regular voltmeter? If so, connect it from the negative terminal of the battery and then touch the other lead to the frame.
If you get 12 volts, then you have found the problem.
Well, that was stupid. I went back and reread what I typed, and realized I did not finish telling what the problem might be.
If you read 12v from the negative to the frame, then you have lost the negative attachment from the battery to the frame and the rest of the truck.
Could be where it attaches to the frame, cable bad internally, but its gone somewhere.
If you read 12v from the negative to the frame, then you have lost the negative attachment from the battery to the frame and the rest of the truck.
Could be where it attaches to the frame, cable bad internally, but its gone somewhere.
Yes, exactly. Like I posted above.
