A family member with a 2001 2.3L Ford Ranger passed away. Before he passed, the truck was rarely started, so the battery was dead even while he was alive. Anyway, I was trying to fix the truck to sell it, so I did what I've done in the past: charge the battery and then boost from another vehicle to get it started. However, the battery would not take a charge this time, so I decided to try to install a smaller battery for a tractor that I had taken off for maintenance during winter. After I had both cables touching the tractor battery posts, all kinds of electrical stuff happened: the windshield wipers turned, the washer fluid pump started spraying, the ABS pump started running, and something on the passenger side from what looked like a connection to the alternator started smoking. I was so freaked out that I didn't notice exactly where the smoke was coming from, but like I say, it seemed to be the alternator. After connecting the battery briefly a couple more times to see what all was running, I pulled the fuse for the wipers, the relay for the wiper fluid pump, and the fuse for the ABS. Then, I connected the battery (I tightened down the cables this time to make good contact). After putting the key in the ignition, everything on the dash looked OK (the same lights as always came on, but I did notice there was no alarm from having the key in with the door open). The problem is that the truck didn't start when I turned the key. I could here the starter motor run, but the flywheel never engaged. Obviously, this sounds like a starter solenoid, but what's causing all the other freaky electrical stuff? I don't want to spend money on a starter solenoid until I know what's really going on electrically (basically, everything that can come on without the key being turned is coming on when I connect the battery). Any ideas?

 

Welcome to the forum

What you describe can't happen unless KEY WAS ON, or there were shorts in the CAB fuse box/ignition switch wiring, maybe a rodent decided to make a home in the cab somewhere and chewed some wires

If the "magic smoke" came out of any parts then those parts won't work any more, simple as that

What you describe about the starter doesn't make sense, it starter motor activated but starter gear was not pushed out to engage flywheel then starter motor is bad, could be the solenoid on top of the starter as well but starter has to come out in any case so you can see whats what
Not a wiring issue, this is a mechanical issue

 

If the alternator is bad (I suspect the smoke was from the diode), then yep, it will have to go (or at least the diode will have to go). I didn't mention that when my family member acquired the truck, he reworked a lot of the electrical stuff. Of course, that was 18 years ago, so I don't think he screwed it up. I'm actually thinking that a wire is crossed somewhere, but I don't know where. It makes the most sense that the short is where the smoke was, but I didn't see anything around there. It's probably a rodent chewing on something like you said, but I don't know why a rodent would take shelter under the hood in the summer. I really just don't understand how so many things can come on without the key even being in the ignition.

 

They can not come on unless the key was on...........or the ignition switch or the cab fuse box was shorted to 12volt power
And in 2001 Ranger wipers are activated by GEM module behind the radio so it may have some shorted wires, but..................if would have to be powered on first, by the key or short at another location

There are a few diodes in an alternator, none would cause a short, they are there to convert AC Voltage to DC voltage when alternator is generating power
Alternator is hooked up directly to battery positive on 2 of its wires, so if it had an internal short it would smoke when battery negative and positive were connected
But alternator is ONLY hooked to battery positive, if it shorted out it would ONLY effect alternator and battery, nothing else would be effected
So you have more than one issue

 

@ RonD I don't know exactly how alternators work, but,

Is it possible that the alternator/regulator has some kind of short so that when the battery was connected, it sent power through the green wire back to the ignition switch ?

Just asking because I don't know if it's possible.

 

I can assure you that the key was not in the ignition when all this happened. I honestly think (pretty sure) there's a short somewhere. I think the smoke on the alternator was from a possible short near there. I suspected the GEM module earlier, but I just don't know. The fuse panels look clean and dry with no blown fuses or anything to suggest a short there. The real question I have is what would cause a short. I see no evidence of varmints in the engine or cab, and the truck has just sit idle for a few months. I could see water being an issue, but it has been abnormally dry here, so even that's a long shot.

 

Yes, if you put 12volts on the alternator end of green wire it would go thru battery light and to fuse 11 in cab fuse box which is connected to fuse 19(no other fuses), but 12v can't travel thru ignition switch to anything else because its physically disconnected as the ignition switch is mechanical, it has 4 separate 12v OUT wires that have no connection to each other inside the switch when in the OFF position

But green wire connection in alternator is a "ground" when alternator is off, that's why Battery Light comes on when key is on and alternator is off(engine off)
Anything is possible but can't see it causing wipers to come on

2001 Wiper power is from Fuse 16 in cab fuse box, which has no connection to fuse 11 or 19
But wiper relays are in Engine fuse box, if there was a short to 12v under engine fuse box in any one of the wiper relay wires that could cause wiper and washer to come on, as they all share one common wire from fuse 16 in the cab