I know finding an electrical issue in a vehicle is like finding a needle in a haystack but I figured I'd ask for some likely culprits first.

First and foremost we just bought this truck a few weeks ago and it's in awesome shape. 160,000ish miles on it, very minimal rust and the engine ran great. However, we have been driving it a lot more than the previous owner and have had a few electrical gremlins but nothing major until a week or so ago I left the lights on by accident overnight (oops). Instead of trying to recharge a crappy battery (walmart brand) I bought a brand new battery and since then we've been having issues.

My GF drove it to work and in the 4-6 hours it sat it needed a jump. The lights weren't left on but I noticed the glovebox light doesn't always turn off, so I figured that was the likely culprit.
After that first encounter with this is it seems like any time the truck sits for more than an hour or so it just won't start. Also, the ground strap from the block to the firewall melted through the vacuum tube going into the MAP. I know the basics of hunting down the short but again, does anybody know of any likely culprits to help me narrow down my search?


Thanks!

 

If the ground strap got hot enough to melt the vacuum hose, that tells me that your ground cable from the battery to the block is either not connected at all or has a bad connection. It was trying to ground thru that strap on the firewall because the main ground was not working.

 

The connector to the ground on the battery is really rough. I had planned on replacing them anyways. I will start there and see where that gets me. Thanks!

 

I would leave that ground strap disconnected as it severs no truck engine operation purpose anyway other than maybe a radio static ground.
But make sure you have a good block ground from the NEG post of the battery. Also make sure you have a good body ground from the NEG post of the battery to the passenger fender.

Engine ground:
Attachment 283226
Attachment 281051

Body ground:
Attachment 277906

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That engine ground looks like it's on the bottom side of the engine, on the passenger side as well?

I'll take a look at it tonight when I get home.

Thanks!

 

Turn everything off. Get an ammeter, hook it between the battery and positive cable. With it dying, you should see a pretty good current. Start removing fuses until the current drops.

 

So, the terminals weren't a huge pain to replace but the battery wires were really badly corroded (I cleaned them as much as possible) and the ground coming from the engine looks very rusty and possibly needs replacing/repairing.

Charging it now to see what awaits!

 

Bringing this back up to see what you have for battery terminals and cables. I supposed I should just bring it up in your new thread, but this one is about the battery stuff, so maybe update this one just to run it full circle and then keep the other one going hunting down the drain.

Sounds like you have either the "temporary" type of terminal, which hardly ever are (temporary that is) or military style terminal blocks, or perhaps one of the high-end audiou connectors. All of which take a battery cable as a separate entity, rather than having it molded into the cable end?
Got pics?

Either way, with your cables sounding so old and tired, as mentioned originally you should be replacing them rather than just wondering if they're good or bad. They may not be the source of your drain of course, but old tired cables don't help you in any way at all.
And new heavy duty ones are so inexpensive in general that they're a good, cheap upgrade. Granted, the originals had a convoluted routing and were covered together in plastic sheathing and run ***** nilly with other wires, but if you don't want to get original and go through the trouble, you can run new ones by themselves and leave the other stuff relatively unmolested.
Still though, not really clean to leave the old one sitting there, but if it's tied up, protected from spinning things like belts and fans, and is disconnected at both ends, it's not going to hurt anything to leave it.
Just don't leave an old one doing the work of a new one.

Paul

 

I'm just going to take it into a shop that specializes in electrical. I know they will take me to the cleaners but there's so much going on with it and I have so little free time to take care of it it's worth it to me.

 

Battery drain can also be caused by a bad solenoid in the alternator.

 

That's the next thing I was going to look at as well, but with the cables, a ground point and the alternator I'm willing to have someone else look at it

 

I think he means power diode (Rectifiers) and not solenoid.
There is not a solenoid in the alternator.

 

Actually, if the battery is draining back thru the alternator, that is the voltage regulator that is bad. It is the voltage regulator's job to disconnect the alternator from the battery when it is not charging.

 

Not true.
The Voltage regulator only regulates the power going to the field windings
The Voltage regulator has no way to disconnect the alternator from the battery.
Most of the time if an alternator is discharging a battery it is because one of the Power Diodes (Rectifier) is leaking or shorted.


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Subford...thanks for the correction. Yes, diode.