91 b250 not charging.check engine light on

[JOFO17]

I have a 91 b250 w/318. It died on me one night coming home. Lights went dim and it died just as I hit my street. I coasted home and the next day charged battery and tested for voltage. Altenator was not charging, so I replaced it. I started her up and still no charge. Am I missing something?

[KimMG]

Some cars have fuses or fusible links in the charging circuit. If yours does, make sure they are good.
Test the new alternators output. New parts aren't always good parts.

[JOFO17]

A bad part off the shelf was my first instinct. So I took the replacement altenator off and took it back to the parts store. He tested it and it came back good. The origonal that they had there for a core, did test bad. He said the voltage regulator may be bad, and start there. None of the manuals I have list a regulator though. Is it in the altenator....or someplace else?

[alloro]

Originally Posted by JOFO17

None of the manuals I have list a regulator though. Is it in the altenator....or someplace else?

If the regulator was in the alternator you'd have a new one...right?

You won't find a regulator because the PCM regulates the alternator voltage. Your problem is more likely a wiring harness issue or a fusible link.

[CoreyE]

Originally Posted by alloro

If the regulator was in the alternator you'd have a new one...right?

You won't find a regulator because the PCM regulates the alternator voltage. Your problem is more likely a wiring harness issue or a fusible link.

If it is a fusable link how would you check it?

[CoreyE]

I have a 1991 Dodge ram 150 van and the altenater is good, the battery is good, but the altenater aon't charge the battery. If it is a fusable link how do you check it, or can it be bypassed?

[alloro]

Disconnect the negative battery cable, disconnect the red wire from the alternator, make sure that red wire isn't hitting any metal and reconnect the negative cable. Test this red wire to see if you have 12 volts to ground. If you do the fusible link is good, if it's dead then the fusible link is blown.

Pull the negative cable and reconnect the red wire to the alternator when you're done testing.

[CoreyE]

Where is the fusable link located. I know it's in the harness but what does it look like?
Is it the soft wires? I need some help Please.

[alloro]

They're up around the master cylinder. It's just a smaller gauge piece of wire several inches long in the harness that will vaporize quicker then the rest of the harness to protect it. There's usually some type of molded plastic tag on it for identification.

[CoreyE]

too

[alloro]

"Too" ... What?