Alternator Problems

[IDI_Journeyman]

i have a 85 F250 with a 7.3 ats turbo/ZF5. Recently the batteries have been dying and I'm almost positive my alternator isnt working. I bought a brand new pair of motorcraft batteries 2 weeks ago and they're already dead. upon further investigation I found a white wire that's been clipped on the top plastic plug on the alt. This truck has the original 6.9 wiring harness too if that changes anything. I'm almost positive that white wire is my problem. If anyone knows where it is or where it goes any help would be appreciated. Thank you

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[IDI_Journeyman]

This is also a reman alternator from napa, i bought it last week.

 

[laserjock]

Check your output. If it's not over 13 V at idle it's not charging.

 

[ifrythings]

That white wire is the other side of the field coil, with out it you will get nothing out of that alternator. From the looks of it who ever crimped those butt connectors on did a horrible job at it as the one on the white wire pulled off. Look around for the other end, it should be by the alt or beside the engine or follow it back from the regulator on the inner fender and reattach it with heat shrink and solder the wire for a permanent fix. Or upgrade to a 3G alt and never worry again.

 

[IDI_Journeyman]

So my friend and I thought we found the wire and we hooked it up, my volt gauge on my dash never worked so I assumed we might have fixed the problem. That night I was driving home and my lights kept getting dimmer and dimmer to the point where I couldn't see anything. Then all on my gauges stopped working except for speedo. Then I started to smell burning plastic so I cut they wire we crimped. Next morning my truck was dead as a doorknob. Battery charger wouldn't even turn on the interior light, had to hook up my dads duramax for about 40 minutes to get it so start. I really hope I didn't ruin anything. I will keep looking for that wire your talking about

 

[IDI_Journeyman]

When we hooked the wire up the volt gauge started working

 

[pelky350]

I have the same plug on my alternator it needs both wires hooked up to work correctly, if whenever hooked up you still have problems I would look into maybe the voltage regulator being bad or a loose connection somewhere in the charging system. Since someone has messed with the wiring there it's possible there is issues other places as well look for and check all the non factory connections in charging system checking for loose or corroded wires would be a good starting point