Hello, here's the blues...

I decided to swap my weak battery out of my 04 f150 with a bigger badder optima a friend gave me for free. I popped it in and realized that the optima was low on charge. I jumped it with my original battery and nothing. Whole lotta clicking and alot of movent in the gauges.

I disconnect the optima from the the trucks negative and jumped it again so the original battery was powering the truck. Then something happened.

I don't think I crossed or ran he wires in series but you never know. Smoke started pouring from the alternator, and a little from the positive wire close to the terminal. I checked the positive wire, it seemed fine. I checked the fusible links, they are fine.

I bought a new alternator, installed it and then the original battery. Truck started fine.

What happens next sucks.

ABS light comes on with the brake light. Shortly after, the battery light comes on with a charging error message. I checked the voltages. 12.5 with truck off, 13.5 with it running.

Also, the stereo is dead. Looked at the fuses. they seemed fine. Drove the truck and it went into a fail safe mode or something......

I should have just left her alone

 

How exactly did you have the cables hooked up?

 

Sorry to hear about the problems. Sounds like you shorted it, but hard to tell what happened from your description. Take the truck in to have it checked out, you most likely smoked a module or two, they do not tolerate much abuse, if any at all.

Let us know what you find out.

 

I wonder, can I drive it there in that safe mode? Any obvious places to check? also, how do I reset the ecu?

 

Yes, you should be able to drive it in safe mode if it's drivable. There's not really any places to check and you usually "reset" the ECU as you call it by pulling the neg cable for a time, but that won't "reset" a smoked PCM/BCM/TCM etc.

 

another update, just got off of work ( graves ) and spent more time under the hood. The area where the wire appeared to be smoking is fine. I metered out the wires, they are okay. I found 3 fuses blown under the kick panel. Stereo, abs are fine.

The charging thingy is still there. I called ford, they think its the pcm. They also said it is safe to drive it there in limp or safe mode.....

Gonna drop it off, will keep you posted.

 

if the PCM is done you wouldnt be able to drive the truck much less start it

 

Isn't there a fuse for the field on the alt? Granted the ols alt was probably toasted. But if the new one isn't working, you might check that.

And I would be concerned about a Dealer that told you to go ahead and drive it with a burnt out PCM! Just saying.

 

From your description it sounds like you you sent 24v through the system frying the battery, alt, and who knows what else. The charge light on the dash means the alt or battery is fried. More then likely its the battery.

 

okay it's fixed. Ford took a look at it and said it was the alternator. They said one of the pins was shorting out. I thought that's weird, it's brand new and I installed it after I f'd the electrical.

They said it would be $580 for the alternator plus 1.8hrs labour. Just under $850.

I thought they are probably wrong but just get it done so I can drive again. Then thay said they won't have the part until next week tuesday as they are out of stock.

I pulled the truck out of there, took it to the alternator shop where I walked to earlier and told them what happened.

He told me there are several alternators for that truck and they had a few for mine depending on what month it was built. Whatever man, your alternator is faulty and it cost $152 for me to figure it out.

He replaced it on the spot for free and it is perfectly fine.... with the exception of fords beautiful mexican made cam phaser / timing belt tensioner engine knock that makes people ask me " hey, is that truck a diesel? "

So the lesson of the day is A: don't try and jump a dead battery in this truck like I did

B: buy the correct alternator, if motocraft is cheaper for you guys in the USA, buy that one. Up here we get hung out to dry for car parts in general.

Thanks for the help guys!

 

FYI an alternator is meant to recharge a battery from its short draw of the starter. It is not meant to recharge a dead battery. What's more is that some sort of charge is required in the battery to start the electrical field in the alternator.

tl;dr- if the battery is dead, put it on a trickle charger, don't let an alternator charge it

 

Glad you got it fixed!