alternator trigger wire?

[Murtaza]

My car died on me a couple days ago and I got a boost from triple-a. The battery pack they used showed the voltage at the battery really low and indicated it wasn't getting charged. So I went ahead and changed the alternator, wiring to the megafuse, replaced megafuse, wiring from the battery and battery terminals because the wires itself were bad. I got a fresh battery from autozone under warranty and figured everything was good to go.. lasted about 1 hr before the gauges started flickering and then eventually wouldnt start up again.

I do have a 3 pin repair harness wired into the alternator because the original harness was nonexistent. I wired it up as shown here (which was working for over a year).. I hope this is correct. http://img189.imageshack.us/img189/2310/3galternator06.jpg

I came across this.. http://www.alldatadiy.com/techtips/Ford/20040726v.html.. "Before the voltage regulator allows the alternator to start charging it needs to see a signal (electrical tickle) from the wire for the battery charge light. It's that electrical tickle from the charge light to the regulator that is the heads up to start charging when the engine is running. Without the tickle from the light the charging system would not work." and traced the wire that goes to the 'battery charge light' and the previous owner just attached it by twist tying it into another wire then pulled it through the bottom to the alternator. I replaced that with 16 gauge primary wire and water-proof crimps and tape.. still not charging.

I double and triple checked everything and I'm thinking maybe there is another fault with that 'battery charge light' wire. Where exactly does that run to and is that the "trigger" for the voltage regulator to let the alternator start charging? Any help is appreciated I'm running out of ideas..

Edit: The battery light does not come on at all in the dash..

 

[Murtaza]

I traced the wire from the voltage regulator to the wiring harness it was half assed and the harness itself was deteriorating. I replaced that wire and tested the voltage at the battery terminals. 12v when car was off, key out. 12v when car was on.. are there any fuses at all besides the megafuse that have anything to do with the battery charging system? I'm about ready to rip out the wiring harness and repair or replace every wire on there.

 

[Murtaza]

Well if anyone was interested or having a problem similar to mine, double check the wiring for that 'trigger' wire or the 'battery indicator light' wire. Mine was corroded and after checking the wiring diagram and changing all the 7.5a fuses, I rigged a wire to the battery into a 7.5a fuse block to that trigger wire and now it's charging away. I'm just happy I didn't have to pull the full wiring harness out.. for now at least.

 

[royalblue]

Congrats on the repair ,can you post any pics and or draw a diagram of the repair you made and point out the fuse :shrug: My guess is nobody chimed because it may not be a common issue or nobody that may have had it understood the question

 

[Murtaza]

Probably not common because my wiring harness is now deteriorating on me and just trying to do this fix was tearing some insulation on other wires apart. Basically I replaced everything on the charging system and narrowed it down to a problem in the wiring harness itself. I traced the "battery indicator light" because I suspected the harness of already being bad and found that the previous owner must have rigged it up ghetto style with just tying in some extra wire in places that it cracked. I repaired it and it still didn't work so I guess my main problem was the previous owner half-assing everything.

According to autozone the trigger wire connects to a 7.5a fuse to the fuse block. I replaced all 7.5a fuses and that didn't do anything.. so I went ahead and ran the trigger wire to a 7.5a fuse and ran it straight to the battery and now its finally getting 13.8-14.1 v

Autozone diagram >> http://img401.imageshack.us/img401/4618/0900c152800a8d2e.jpg

the wire in question >> http://img34.imageshack.us/img34/2218/altdiagram.jpg

how i rigged it to test if it would charge >> http://img202.imageshack.us/img202/619/imag0119y.jpg

I had to put some electrical tape on the ends of the connectors that went to the fuse and put a bit of silicone or rubber on them so they wouldn't arc or touch each other since they were so close together. Hey, it works for now and until I tear apart the whole wiring harness this will have to do.

Edit: rig a switch to the interior from the 7.5a fuse because leaving the 7.5a fuse connected directly to the battery will draw power and drain the battery

 

[royalblue]

I had to do something like this when I took My alternator out because my light came on

but it sounds like your issue was a little different