Regulator Excite “E” Terminal

[deleted user 89485]

I have read about the quick fix. I tried it and my regulator will come on, however I am trying to find the source problem. I have tested the E terminal wire to the K11 relay and it is good. I just do not see in the schematics what actually turns on the coil in the excite relay. I have a 2006 M1078A1R. Thanks for any help.

 

[deleted user 89485]

CB77 has also been checked and is good. I just need to know what controls this relay.

 

[Suprman]

The quick fix was really only for first gen trucks. The polarity box under the spare tire is involved with charge regulation on the newer A1 trucks.

 

[deleted user 89485]

I was also told that the low oil pressure light on the dash is what energizes the K11 relay and turns the E terminal on. Good oil pressure keeps the relay off, in a Normally closed state, sending 24vdc to excite the regulator and when the dummy light comes on it energizes the relay and opens the contact thereby shutting off the 24vdc to the E terminal. LBCD has been tested and is good. Can anyone confirm this?

 

[deleted user 89485]

According to the schematics, the LBCD has nothing to do with the excite circuit for the alternator or relay K11.

 

[Suprman]

It looks like 86 is the positive that would engage the relay. Schematic appears to show it going to the cat ecm. But it appears there is also a connection on that line to neutral start relay 87 terminal. There is a resistor r11 between the connection and the excite relay. There is a transistor t2 that appears to be able to remove the ground from the relay.

 

[Suprman]

 

[Suprman]