Hi guys,

I searched the forum and couldn't find a thread that answers mt problem.

Started truck and it ran for 40 minutes. Then dead. Jumped it and it ran for 20 minutes and dies, gauges going haywire. Jumped again and got another 5 minutes.

Towed home and replaced alternator, still not charging.

Replaced batteries as they were 8 years old and weak, still not charging.

Before the issue, would read 14-14.2v running. Now its running 11.8-12 but does seems to discharge steadily.

Is there a fuse I need to check in the 2000 SD? Any other things to check before I have it taken somewhere?

Thanks!

 

You may well have a bad replacement alternator, if it is a NAPA, or any of the other box stores for that matter, most are sent to China and rebuilt there, I have seen at least 3 bad out of the box ones in the last 5 years.

Might also check all of your cables for rubbed areas, and the ground cables where they hit the frame, make sure they arent damaged or arcing.

 

Thank you. I bought the alternator from DBelectrical, online.

I noticed the "battery" light doesn't illuminate when I turn the key on either, can that be indicative of the root problem?

 

I would take the Alt off and take to a parts store like Autozone and have them test it. It is test fine then I would go and check all the fuses in the box in the engine compartment. I had that issue about a year ago and one of the wires melted in the back of the engine. Good luck.

 

Replaced the wire and all was good after that?

 

Yes, After I found the issue which took a couple of days and few blown fuses. I just cut the melted wire and spliced it back together and I was good to go. I spent a lot of time tracing wires and testing them to see where this issue was.

 

Thanks guys, I'll try and check it tomorrow.

Just curious, what fuses were blowing? I don't have any blown that I know of. Is there some other fuse block I should be looking for?

 

One of the Mega fuses was blowing. I just started fallowing the lines that went out of the Alternator. Make sure to check the fuses under the dash as well to make sure that nothing is blown. And last is have the ALt checked before you go barking up a tree that you do not need to.

 

there is also a fusible link that if burned out will not let the battery charge.

 

I looked for a fusible link but couldn't find anywhere in the harness. Any direction as to where to find it?

I had the old alternator checked, it failed. Checked the new alternator, it passed.

Checked resistance from battery negative to alternator case, zero ohms. Positive post to positive feed on alternator, zero ohms. There is 12.7 volts to the back of the new alternator...

Dash "battery" light does not come on at all when key turned on. So I'm thinking a fuse, but haven't found anything burned out.

Any ideas on where in wiring harness I might find the fusible link?

 

Should be at least 13.5 volts loaded. Is the 12.7 volts with all accessories IE headlights, wipes, radio, etc. on? with engine running? That's too low.

Make sure all of your battery cables are good.

I only buy from Motorcraft just for these high defect rates from the aftermarket.

 

No, that reading is with engine off. 12.7 at battery, 12.7 at back of alternator.

Running, i hover right around 11.8-12.2. drops with accessories going, but bumps back up when they're turned off. So some charging taking place, just not the 14.2-14.5 that it should be....

 

that is not charging at all.
it is only reading battery voltage.

 

I agree....your alternator is not charging.

 

I checked as far as I could and couldn't find a fusible link. Any idea where t's located, maybe I just missed it?