Must be electrical...?

[TSchroed189]

Hey guys, I'm having some trouble with my monster. The batteries were tested at O'Reilley's and he said they were both fine, and I can jump it with my wife's little explorer. Now I'm taking the alternator in to get it tested too, but it looks brand new! Used to be, once I started her up, she'd charge the battery up to what looked like 14 on the dash, now she's barely maintaining 9-10 while running. Just in case it's not the alternator, do you guys have any ideas as to what else it might be? Thanks in advance!

-Travis

 

[killen1]

Battery cables could have corrosion

Check.grounds better yet do 1/0 cables from frame to motor, motor to cab then back to frame.

Could be the old style alt. If you havnt switched to a 1g alt its money well spent. The old alternators im sure its the rectifier on the back side that likes to wreck havoc. Not sure what else have to double checked your wires in and around alternator?

Also dont go by the gauges on dash basic idiot lights. Have you done a check with the truck running with a voltmeter? Or that box o riellys uses just want to clarify most prefer a hand held voltmeter if batteries are good. Then with the truck off it should read 12.7 volts and running should be over 13.5 anything less then 13 your not charging your batteries.

Sorry for long rant this should get you started.

 

[TSchroed189]

How do I do a 1/0? Wires are always hardest for me because they're so damned hard to chase. How do I get a 1G alt? I can't find them online, all I can find is how to install them. Thank you!

 

[bbjordan]

You want a 3G (Third Generation) alternator. It has the built in voltage regulator. You already have a 1G. That was probably a typo by killen1. The conversion is fairly simple. There must be several threads on this site on how to do it.

 

[killen1]

Yes typo darn smarphone keyboard wont go any larger 3g yes and the wire i would just find a pair of thick jumper cables. And cut to fit but I'm cheap and can make them work. Thanks bbjordan got into a rant but you can find threads everywhere on here also with diagrams. If the truck isnt hacked up

 

[TSchroed189]

I'm finding threads on how to do it, but even with Google, I can't find what I'd pull a 3G alternator off of. Do they come off of the 7.3 Powerstroke? Thanks!

Sent from my SM-G900V using Tapatalk

 

[riphip]

http://www.ebay.com/itm/ONE-WIRE-FORD-MUSTANG-3G-Small-Body-ALTERNATOR-1965-66-67-69-70-1975-Generator-/131992775499?hash=item1ebb61eb4b:m:ml93mLkoouysCV7rv8i0j0w&vxp=mtr
This is the type I have on my '86. Change the pulley with present one.

Rick