So long story short - I was trying to fix the power windows motor/regulator, and during one of the testing sessions I dropped a Costco battery in WHILE THE KEY IS AT THE ON POSITION.

I quit defending myself a long time ago. I'm an engineer, too. Whoa, you say.

In the debugging process, I came across this forum dozens of times and it helped me tremendously. Time to give back.

Here's a list of things that went wrong -

1) Two wires from solenoid to alternator rectifier are melted. The fusible links did NOT.

2) Alternator rectifier is bad. Possibly other parts of the alternator too, but I replaced the whole thing so I don't know for sure. The bad rectifier ended up frying the rectifier connector too AFTER the battery was connected correctly. In my case, some diode in the rectifier was SHORTED, not opened, as my rudimentary circuit analysis revealed. Lesson - in this kind of massive electrical failure, test the alternator first before you proceed elsewhere.

3) The ignition control module was dead. Very dead. This created a no-spark condition. After following a pretty elaborate test procedure I finally pinpointed the problem. I was getting worried that the ECU was fried too, but the problem ended in the ICM.

4) An ACG fuse connected to the radio head unit was blown. Fixed it this morning.

5) A positive battery wire. The old one just looks awful and it makes a high-impedance connection to the + terminal, which probably caused the old battery's untimely death anyway.

Of course, I replaced a few things that wasn't needed to be replaced, including:

1) the rectifier connector. The bad rectifier was responsible for its demise, see above.

2) Ignition coil. I worked backwards to fix the no spark condition.

3) The window regulator. The motor has excessive resistance, and the regulator wasn't broken after all, but I took heed of some bad advice from the internet (not this site though). This has nothing to do with the battery fiasco.

4) A bunch of circuit testers, ICM removal tools, piecing probes, and so forth. I can sell most of them for a few bucks I suppose...

A side note - since I learned that ICM gets toasted often and one can buy a custom wire harness to relocate the ICM to the fender, I made my own ICM relocation kit, but decided not to mess with it for now. If anyone wants to find out how to do it yourself or want to buy my cheap harness, let me know.

So that was my story. All in all it cost me around $250 to do all these. Ebay was the primary source of parts.

 

Welcome to FTE & congrats on owning up to a major cluster £#@%

You'll fit right in.

 

Thanks Scndsin. I was going to hide my silly/bonehead side a bit longer but hey, no one's fault I didn't register here before taking the hammer to the truck.

I'm going to repeat a piece of advice I read somewhere - when you suspect any shorted/melting situation, check the alternator first before attempting to start the truck. It's among the first things to break and it's likely to wreck other things.

I was lucky I didn't end up frying the ECU. On my model year the ECU's a pain to get off, and there are so many ECU models for the same year it's nearly impossible to figure out which one to buy without looking at the thing.

 

Depending on which year truck you have, the ECU is protected by a diode going to the ECU power relay. Reverse voltage will not cause the relay to activate via diode and protects the ECU.


The rest is not protected as much, check EVERY wire at ignition switch I have seen reverse battery hookups fry wires at the ignition switch and fuse box.

 

welcome to FTE.
look at it on the bright side.

at least you did not set it on fire and burn it up.

and no, i have not done it but have seen others that have.

 

If I had to list every boneheaded mistake I've made while repairing things, it would look like a copy of War and Peace.

As for you being an engineer...I'm a medically retired toolmaker. I'm the one that would take what an engineer thought up, and show them just how it's not going to work the way they designed it...then re-engineer it to make it work.

The nice things about these old trucks is that it takes a lot to kill them, often times more than what we can throw at it.

 

I thought only a REAL IDIOT would hook up a battery backwards...

A couple years ago, went down to shed to start my lawn tractor, battery was dead, just one click, that was it. Went back and lugged in old but still serviceable 12" top Type 24 battery, and actually remembered to bring the jumper cables with me.
It was pretty dim in the shed, and these old eyes need a lot more light than they used to. Could clearly see colors on tractor battery wiring, attached cables there. And when I went to connect the last jumper to the booster battery... POW! Shower of sparks! Melted off part of the lead terminal post on the booster battery. What the heck?

Yup. In the semi-darkness, I mis-identified the black raised "+" and "-" markings molded onto the booster battery. Luckily, the dead tractor battery had enough guts left to resist a total polarity inversion, which saved all the electrical and electronics on the tractor!
DUH!

 

so does this mean that you finally admit you are a card carrying member of the "real idjiot "klub??

 

What? NO!
I blame it on the low-light conditions and my aging eyes.
I'm a VICTIM, I tell ya, a VICTIM!

 

I had a customer in the shop with an 89 E150 Conversion Van who had a shiny new drop down large screen TV installed, well it took more juice than the stock battery had when not running so he soon found out it would run the battery dead if the engine wasn't running. Not having a clue, he had his neighbor pull his tractor trailer along side to give it a jump start. That was screw up number one, 24 volts in a 12volt system. Bye Bye new TV, battery, alternator, ECM, Radio, Premium Sound Amp, power antenna motor, TV antenna motor and controller, rear radio, and the TFI module.
A week or so later the truck was back, dead again, this time the battery had a hole blown in it where the positive terminal used to be and a chunk of jumper cable still melted to the negative terminal. The story I got was that he learned his lesson about getting a jump start from a big truck, so this time he used his work truck, a twin battery powerstroke diesel. This time, even though he had the right voltage, he again reversed the polarity and fried just about everything all over again, this time the list included a good portion of the main wiring harness around the starter solenoid.
$1800 later he's out the door again. A month later it was back, this time he wised up, he didn't jump start it, he went right out and bought a new battery, the biggest thing Sears had that would fit. He connected the new battery, again he reversed the terminals and fried even more parts. This time 1450 CCA battery was still connected in reverse, the cables melted right to the battery, but the damage was far worse, he ruined the engine harness, battery, solenoid, melted the nearby heater box, and again wiped out all the same components as before. Basically anything that was on and was grounded took a hit. Again we fixed it but he gave up on the TV, he blamed the TV for the problem, not his stupidity. He swore he'd never own another Ford, "The things just cost too much to keep going". It wasn't long before he showed up again with a Cadillac that had some aftermarket stereo installed wrong and it took hours to sort out the butcher job installation on that one too. Luckily he gave up on messing around with the battery or anything under the hood by then. (He was also the same customer who drove in one day with a flat tire on a Toyota Avalon which obviously had been flat for a long, long time. About two inches of the rim was ground away, the tire was gone, he handed me the one sidewall and bead that had rolled off the rim about 30 miles prior to making it to the shop. He blew a gasket when we told him he needed a new rim and a new tire. When I looked in the trunk, he had a matching spare, ground down just as far as the one on the car. The worst part was he wasn't some young kid, the guy was in his 70's or better. No telling how long his pattern of destruction had been going on.

 

LOL
By chance, was this in Sw Florida area? I have heard a story about a similar scenario few years back!

 

It was up in Jersey but the van had FL plates, but I think he had moved here permanently by then. I never really asked, he wasn't the most agreeable customer, especially after he got he bills for the repairs. All he did was blame the vehicle.

We had another guy who reversed polarity in his Ford Taurus but he was trying to use the new car to charge the batteries in his electric golf cart thinking it would work better than the 36 volt charger that came with it. The resulting 36 volts in the Ford's electrical system fried just about everything but from what the guy said it ran for an hour connected to the golf cart. He did say the dash lights got really bright and the radio's LCD screen glowed orange before everything went dead and the car died.
After we replaced all the damaged parts and two wiring harnesses that melted, including one going back to the fuel pump, he drove away saying he was going to turn it into his insurance company. About three months later the car was back in the same shape, this time he left the headlights on or something that drained the battery down so he found a way to use the 36v golf cart charger to charge the battery and get the car started. That time he called the insurance company first. They looked at the car and about a week later the car got towed away, I don't know if they totaled the car or if he was still fighting with them about it. We never saw the car or that guy again.

We had another guy decide he wanted to add a second battery to his 460 van, he bought the second BXT-650 battery but made up his own cables, in wiring it up he wired the batteries in series, the minute he turned the key on things started to burn up. He lost the radio, alternator, ecm, TFI module, and most of the light bulbs that came on at the time. He disconnected it and had it towed to the dealer where we found the DIY wiring job.

 

That's too funny, he had Florida plates! May have been the same guy.


I got a free car once due to a backwards battery hook up. Smoke job big time from under the hood, engine harness was charcoal. Few trips to the junk yard and I got it running and made some $$ selling it. It was a Chevy car(forgot model) beyond burnt engine bay harness and alternator, the rest survived as the fuses did their job.


Just today I had a service call..... for a backwards battery in a burglar alarm panel! Had to replace the control board. Mr was color blind so he could not see the red wire to red post on battery from the black coloring.

 

Hi Supernova1987a -

I know this was sometime ago now, but per your #:
4) An ACG fuse connected to the radio head unit was blown. Fixed it this morning.

Can you tell me where this fuse is located, please? Is it on the radio, inside the radio, in the main interior fuse holder panel or elsewhere - gracias!

 

The main/fsvtoey radio fuse is in the panel under the dash near the left door, it does a few things in addition to the radio. If you have an aftermarket radio often those have a fuse of their own, typically accessible from the rear after the radio is pulled out of the dash.