Charing system

Reply Subscribe

Thread Tools

Search this Thread

Jun 1, 2005 | 01:54 PM

gjpose

Thread Starter

New User

Joined: Jun 2005

Posts: 3

Likes: 0

Charing system

I have a 1990 F-250 7.3 4x4. The alternator was not turning on and I was running off my batteries for a week now. I got the alternator to work by bypassing the regulator and running one cable to the battery. What i need is a wiring diagram of the charging system. When the truck is running at idle it is at 13.6 volts and when i give it gas it goes to 18 volts is that normal? I amd not familiar with diesel but eager to learn. Please any ifo would be very greatful. thanks Glenn

Jun 1, 2005 | 07:14 PM

IB Tim

FTE Leadership Emeritus

Joined: Jan 2003

Posts: 161,999

Likes: 75

From: 3rd Rock

...Welcome Glenn, to Ford Truck Enthusiasts! Please read the Guidelines, it will help you to navigate through and understand this site.
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!

Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.

Jun 1, 2005 | 07:51 PM

trike1946

Logistics Pro

Joined: Apr 2004

Posts: 4,292

Likes: 5

From: NJ where fun comes to die

Welcome to FTE. I would take your alternator to get tested and replace the regulator. 18 is much too high. Also test your batteries while you are at it. Test them seperately, and disconnected. Good luck with it.

Jun 1, 2005 | 08:37 PM

deanj

Senior User

Joined: Nov 2004

Posts: 315

Likes: 0

Get a regulator asap. You can over charge the batteries - warp the plates, even boil them. Get the alt. and batteries checked (your local parts store should do it)

Jun 1, 2005 | 09:42 PM

gjpose

Thread Starter

New User

Joined: Jun 2005

Posts: 3

Likes: 0

The alternator, regulator and batteries are brand new. I have had them (batt and alt.) out twice already in the last 2 days and brought them to auto store to be tested all good. On the regulator I have the 2 wires that got to the alt. marked S(white) and F(orange) and 1 that is not coonected to anything marked A(yellow wstripe) and 1 I lose in a the bundle marked I(green red stripe). I am completly lost. Does anyone have a wiring diagram? I got a book on ebay tonight it most likely won't get here for a week. Thanks for the feed back. Glenn

Jun 3, 2005 | 12:35 PM

willd

Elder User

Joined: Oct 2002

Posts: 743

Likes: 1

F is for field pole on the alternator. I is from the ignition or powered by ignition. S I can't remember. I think (I) is supposed to be hot when the key is on. F goes to the field terminal on the alternator. It should be marked on the alt. The whole harness is pretty simple. The wires may be spliced in for the volt guage. Check autozone.com to see if they have a wiring diagram.

Jun 3, 2005 | 03:26 PM

ryanvaughn

New User

Joined: Dec 2004

Posts: 7

Likes: 0

From: Buckeye Lake

Your problem is most likely the yellow wire I had sort of the same problem and ended up the wire was so corroded at the regulator it broke I had to replace the starter not long after cause I was over juicing it. I believe the yellow wire runs to the alternator hot. Is it loose next to the regulator if it is it may have broken out of the connector harness.