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wildcard · Post by **wildcard** » Sat Feb 24, 2007 10:37 am

On a 300, which connection does the pos. clamp go to to check output voltage?

splavin90 · Post by **splavin90** » Sat Feb 24, 2007 7:38 pm

the thicker wire goes on + and the smaller one goes on F

wildcard · Post by **wildcard** » Sat Feb 24, 2007 9:07 pm

Thanks

wildcard · Post by **wildcard** » Sat Feb 24, 2007 9:40 pm

OK, this may sound a bit odd but here goes.

It seems when the engine is running, something is drawing power down. To about 11.9 volts. After it sits a while not running it gradually goes back up to 12.5 volts. I actually watched it do that. I know I haven't had much sleep lately but .............
Also when it runs a while it won't start back up for about 10 min. Then starts with no problem. Acts like a dead batt until it cools off a few min. All this on a new engine.

QC · Post by QC » Sun Feb 25, 2007 1:25 am

Your alternator is not charging. You are just reading battery voltage. The battery will recover a little on it's own, but it is going to get progessively lower until it's too low to start the truck.

wildcard · Post by **wildcard** » Sun Feb 25, 2007 9:26 am

It's a brand new alt. I got yesterday and the old one was doing exactly the same. I'm gonna try to go get the batt. and alt. checked this morning. I'll let you know what I find out.

ToughOldFord · Post by **ToughOldFord** » Sun Feb 25, 2007 9:33 am

Don't forget the regulator.

wildcard · Post by **wildcard** » Sun Feb 25, 2007 1:45 pm

I took it to AutoZone and they checked the battery and regulator. Both were bad. It still won't show any more than 23.3 volts. That's with the engine off. 11.8 with it running.

I've double checked the hookups on the alt and they are ok. I've about replaced everything now so it may be in the wiring. Any ideas where to start looking?

wildcard · Post by **wildcard** » Sun Feb 25, 2007 1:47 pm

That should of been 12.3 with the engine off.

fordman · Post by **fordman** » Sun Feb 25, 2007 2:17 pm

maybe the wiring was hooked up wrong on the alternator. did it work before the engine swap?

wildcard · Post by **wildcard** » Sun Feb 25, 2007 4:36 pm

As far as I know it worked before the swap. Never had a problem that I recall. I took a pic before I unhooked it to be sure it went back right.

I did wash the engine bay with a pressure washer prior to install.

ICEMAN6166 · Post by **ICEMAN6166** » Sun Feb 25, 2007 7:15 pm

is there a fusible link in the harness on that?
i see it in the 70 diagram.you would still have all your other power items working except charging if it was bad.

wildcard · Post by **wildcard** » Sun Feb 25, 2007 9:02 pm

Yes, it does have one. Could I bypass it by cutting it out? Or use a jumper wire to go around it to see if it makes a difference?

fordman · Post by **fordman** » Sun Feb 25, 2007 9:42 pm

yuo could try just temporarly bypassing it until you figure out if thats whats bad or not. if it is bad then you are suppose to replace that link wiht the proper size wire to recreate the fuseable link. sorry i don't know which size that is.

wildcard · Post by **wildcard** » Sun Feb 25, 2007 10:20 pm

Tried it. Didn't work. Looks a job for a prpfessional.

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