12 valve cummins wiring problem

[KYSAR725]

a friend of mine just installed a 12 valve cummins out of a 96 dodge and we are having a problem with the alternator wiring and the fuel solenoid wiring. we installed it into a 98 chevy suburban and converted it to the solid axles but we just cant find a way to get the alternator to charge, we used a regulator from an old ford pick up but that didn't work. any help would be a great help. and yes this thing is cool!

[Barrman]

The fuel valve is easy. 12V positive when you want it to run. Make sure the engine is grounded to the chasis.

The alternator should be an internally regulated unit. I am at home and don't have access to any schematics for that truck. However, it should have a positive in that is always hot it should have a post this wire attaches to, an exciter wire that turns on with the key but is seperate from the fuel valve mentioned above. Then a positive out that goes back to your battery.

[Kamikaze12volts]

on mine ( 93 6bt ) it was externally regulated so i use a regulator from my local autoparts and 2 wires to have it worked. I know it's the same alternator as a Jeep XJ because when the bearing gave up , i just drop a jeep's alternator in it because it was $60 cheaper then the dodge ram one.

[amphi]

The fuel valve should have two coils.

One intermittent duty for start that is pulled in thru a relay energized by the ignition switch start position.

The other coil is a continuous duty holding coil energized by the ignition switch in the run position.

You can bypass the relay for the start coil by wiring it directly to the starter side of the starter solenoid.

I'll have to look at the wiring diagram for the alternator issue. I have a factory service manual.

[amphi]

Fuel solenoid should have three wires

Tan wire -- Ground
Black wire -- Ignition on position
Violet wire – Start position

[tndonor]

Another option that I did on my J10 Cummins was replacethe fuel solenoid with a push pull cable. Those solenoids are a little pricey.

As the alternator goes, that is unfamiliar territory for me. I can tell you my friend has a 94 Cummins in his chevy truck and it is externally regulated. Not much help but it appears there is both out there.

[KYSAR725]

we got the solenoid working but still have the alternator problem, thanks for the help.

[amphi]

The alternator is externally regulated by the PCM on my 1997 dodge and it shows the same in the 1994 factory manual.

It has four wires:
Ground
Battery +
PCM pin #20 - Gen field (regulated)
PCM pin #57 – B+

Kamikaze12volts suggestion above might be your best bet.

Are you using the original PCM?

Did you bypass the relay on the solenoid?

[Barrman]

Sorry for any confusion with my alternator post above. The 6BT I have here in class has obviously a non Dodge alternator on it.

[amphi]

Sorry for any confusion with my alternator post above. The 6BT I have here in class has obviously a non Dodge alternator on it.

Tim, the one you have is probably the best way to go if not using the PCM -- single wire setup.