alternator exciter no voltage need help

[jetboat36]

so i changed my alternator because the old one wasnt charging the battery and even with the new one still the same thing so i check the fusible link with a voltmeter is good and as well the exciter wire goes to the alt should have 12volt when the key is on but nothing !!the ecu control the voltage going to the alt ? and also when the key on the dash battery light dont come on so pls need help

 

[schiker]

The passenger side battery has a spacer between the positive battery cables one goes to the starter I think the other crosses to the driver's battery. This spacer can corrode or bolt loosens and lead spacer gets deformed some then connectivity gets intermittent. It took out an alternator for me jumping in and out of charging. This side also tends to make the dash voltage low. It's worth a check.

I like the mod where you cut off all the side post cable rubber and put a stud /nut in the side post to make a mock top post connection.

 

[WarWagon]

What year? Did you keep the diesel sized, larger, pulley off the old alt for the tach? Can you get the core back...

Charge lamp not on means it will not work. That lamp circuit is the turn on source for the alternator. Burned out lamp, bad connection at alternator plug connection, fusible link, or fuse may be bad.

 

[jetboat36]

ok thanks but i fixed the alternator now is charging but the tach still dosnt work so what you thing is the problem now ?

 

[jetboat36]

the pulley is the same size yes how much voltage should the tach wire get when the truck is started ?

 

[WarWagon]

What was the fix? That other wire off the alternator plug goes to the tach...

 

[jetboat36]

well i had it plug in wrong plug but now i got the good plug alternator work but the rpm doesnt such a headache any idea why the alternator work but not the tach ??

 

[JMJNet]

Did you see DieselPro reply on your thread in the other forum?