soxfan82

Hi everyone,

I'm new here, this is my first post, but it certainly won't be my last, as this truck keeps me busy! :-)

Last night I went to re-park my '93 F-150 (4.9L 6cyl, 2WD) and it didn't turn over the first time, but did the second time. Parked the truck, then realized I parked badly so I went to park it one more time, and it was 100% dead. No cranks, no lights, sounds, nothing. Checked again this morning and it's still 100% dead. Here are some things I know so far:

- Battery is 5 months old and is what I consider to be a quality battery.
- Attempted jumping the truck to the battery terminals unsuccessfully. No cranks, lights, sounds...anything.
- Multimeter shows 12.5v on the battery
- Connections to the terminals are tight. Connection from the negative terminal to the ground is tight. I doubt the terminal posts have corrosion as both the battery and the terminal connectors are new as of 5 months ago. However, the actual positive and negative wires coming off the battery are original, and look like they've seen better days, and the ground connection bolt appears to be corroded. Photos attached. I'll attempt cleaning off all of these things later today after work. But still, it worked fine forever, and then magically didn't work last night... right after it did work
- I don't see any blown fuses in the fuse box from a visual inspection. I need to pull out the relays I think, and check those. Is the power relay the one in the bottom-right?
- I want to check the other end of the positive wire to check for continuity across the entire wire, but I'm not sure where it ends up. I see it going down into the engine block, but I can't find the same wire sheath coming out the other side to the fuse box.

Any help in figuring this issue out would be greatly appreciated!

Thank you.



...

Steve83

Click this & read all the captions:


(phone app link)

Your 2nd pic shows nothing wrong.

soxfan82

Thanks - so if I'm reading it correctly, you're thinking that I should consider replacing the terminal ends? I don't disagree with you - mine are exactly those crap ones that they say not to buy in the thread you shared.
What I think I'll do when I get back from work is test a little ways down the wire and see if I'm still getting 12.5V. If I am, then I know nothing is wrong with the terminal ends. But I'd be surprised if nothing was wrong with them.

I'll let you know what I find out!

Thank you.

soxfan82

RunninHorse

I wouldn't think it's a battery issue if sometimes turning they key lights up the dash and other times it doesn't. I also suspect something in the ignition. I'm not real familiar with that engine. See if you can find how to test the key lock cylinder.

Edit: Does this truck have an alarm system? They can sometimes cause problems like this.

soxfan82

PerryB

It's your terminal ends, they're oxidized/corroded inside the clamps. Give them a good wiggle/twist and it'll probably start right up. Then pull them apart and clean them. The immediate problem is probably under the clamp plate in the first picture.

soxfan82

Solved.

PerryB, like you thought, and like Steve83 mentioned, the terminal ends were corroded inside the clamps themselves, where the bare wire gets clamped in. It was messy inside, especially on the negative side - almost appeared that it had been burned inside? Even after cleaning the metal looked burned, so I flipped it over when I put it back together. On the positive side, that same part was mostly ok, but the wire ends were very oxidized.

I didn't think it would be this simple, but I simply took everything apart, cleaned the wires, the crimp connections, the bolt where the negative attaches (it's still green but better than it was) and also the battery posts (which looked fine but why not), and now it starts up just fine.

Thanks guys! I really didn't think it would be that simple, because I could measure 12.5v on the terminals before. I really thought the problem was in between the terminals and the cab somewhere. Guess not!

Steve83

You haven't repaired it - you've just started over with the same crappy terminals, and they're going to fail the same way again. But faster this time, since they're already aging & corroding.

soxfan82

Steve83, I agree. I didn't mention this in my last reply, but I do intend to put new & better terminal ends on, and solder them. I also intend to look into replacing the wires themselves. I'll be doing that sooner rather than later, before it all craps out again. In the short term, I needed to get the truck running, so it's a short term victory!

Thanks again!