Alternator voltage fluctuating ac delco si19

[kitepilot340]

I’m trouble shooting my 2001 3988 with 6bta m3  Ac delco si 19 alternators 3 pole battery isolater that showed 13.8 v on center post 13.11 on other 2 posts with engine running

I had low voltage and erratic tach and voltage at cruise after warm up  so removed the Alternator and  had it tested 

The shop claimed no output and shaft was bad and rebuilt it.

Same issue  

The upper and lower helm show only 10.8 v on the exciter pole of the switch and I can’t find the wire that goes to the alternator from the ignition switch because they are painted

Does the exciter wire go from both keyed ignition switch’s to one of the 3 solenoids and then to the alternator?<br />Is there a fuse on the exciter wire that may  be causing a bad connection?

Can I jumper the alternator to the battery to bypass the ignition exciter ? Its odd the ignition switch only shows 10.8 v  when I test at the switch<br /><br />

Plug in the alternator looks perfect

Thanks 

 

 

 

 

Topic

[Tony Athens]

3-Wire Alternator Regulator Diagram

Cummins Marine Delco Style Alternators – Identification

 

 

 

[kitepilot340]

Correction

It’s a 4 wire 3 on the plug and the positive wire

[Author]

Replies