M1009 passenger side alternator

[wiccantoy]

The alternator lights come on when the key is turned on but then go off again before the truck is running?

that is correct. the same as my f450 dually

 

[dirtroadoutlaw]

Have you checked the "tickle" wires going to the alternator in question? These alternators will not charge without a hot tickle wire.

 

[dirtroadoutlaw]

Btw, hey guys. <<< noob to the site. Love it so far

 

[wiccantoy]

Have you checked the "tickle" wires going to the alternator in question? These alternators will not charge without a hot tickle wire.

Can you define where and color of the wire in question? And the best way to test it?? Not sure whats tickle wire is

 

[dirtroadoutlaw]

The black and red wires that are coupled together in the flat plug that plugs into the back corner of the alternator. Should be getting 12 volts across them with the ignition switch in the run position.

 

[Warthog]

The black and red wires that are coupled together in the flat plug that plugs into the back corner of the alternator. Should be getting 12 volts across them with the ignition switch in the run position.

First off welcome to the site. Hang on and enjoy the ride.

Second. Do you have any experience with the CUCV electrical system? The wiring is simular but very different.

You may want to spend some time reading the CUCV TMs and studying the wiring diagrams.

In this particular thread we have been talking about the GEN2 (passenger)alternator. Althought it is a 12v unit, the readings you just spoke about will be 24v and not 12v.

The CUCV alternators do not use the case for a ground. They have an isolated stud that serves as a ground. The GEN2 unit is fed 12v to this ground stud and the output of the unit is 24v

The "tickler" or excitor wire for GEN2 is also different. It is 24v instead or 12v.

The red wire is 24v at all times and the brown wire is zero volts with the key off and 24v with the key in the run position.

Now when we are talking about the GEN1 alternator (driver side) the voltages are 12v and the ground stud is attached to the engine for a regular type of ground. This alternator doesn't have to be an isolated groound unit, but GM put one there so the military only had to stock one type of alternator for the CUCVs (the M1010 is a separate beast).

 

[dirtroadoutlaw]

I've spent way more time in the tm's than most. Having repaired several issues on these Chevy cucv's. As far as to graft a civy fuse panel into one and a dual headlight wiring harness into my own while retaining all b/o light function. My only problem is retaining every little fragment of information that I've stumbled upon through those processes which is a heck of a lot when dealing with a hybrid 24/12 system like this. Honestly, I've never worked on the 24v although that voltage difference should have registered however the principal is identical in every way. Just add 12 volts. Sorry for the misinformation.

Thanks for the welcome. Glad to be here. I've loved mv's every since my dad's willys when I was a little kid. I will update all of my info when I can make time to sit at my computer to do so.

Back to the subject as to avoid thread jacking.

 

[mistaken1]

that is correct. the same as my f450 dually

The exciter circuit passes through the lights. They should not go off until the alternators are producing electricity in a stock system. If they go off before the engine is running something is wrong.

 

[wiccantoy]

ThatThat's great. Even more for me to search for now.

 

[wiccantoy]

So any idea where I should start?

 

[mistaken1]

From this link: (there are pictures at the link)
http://www.steelsoldiers.com/cucv/56247-alternator-trouble.html

Welcome to Steel Soldiers.

Visit the CUCV Wiki page and download the Tech Manuals that are listed

Cucv Wiki - Steel Soldiers::Military Vehicles Supersite

From your description your GEN1 is not working. With the key on and engine not running, both idiot lights must be working for the alternators to work. They are part of the excitor circuit.

When testing the alterernator wiring on a stock system you should have the following

GEN1
large red wire - battery voltage from the front battery via the 12v terminal block
small red wire on 2plug - battery voltage from the 12v terminal block at all times
small brown wire on 2plug - battery voltage when key is in run position
large black wire - ground from engine block to alt case ****** This is probably your problem ******
small black wire w/white stripe - ground for STE/ICE diagnostic system
small brown push on wire - tach for STE/ICE diagnostic

GEN2
large red wire - 24v from both batteries via the 24v Positive terminal block
small red wire on 2plug - 24v from both batteries via the 24v Positive terminal block at all times
small brown wire on 2plug - 24v via the GEN2 relay when key is in run position
large red wire w/white stripe - 12v feed from 12v terminal block
small orange wire - ground for STE/ICE diagnostic system
small black wire w/capacitor - removed on most trucks

The CUCVs run most of the truck off of GEN1 which is on the drivers side and the front battery. The starting system, glowplugs and the diagnostic system run on both batteries and GEN2 which is the passenger alternator and feeds the back battery.

Check and clean the 2plug connector on the alternator and replace it if necassary. Also check the black ground wire on GEN1.

Right click on thumbnail and choose "Open Link in New Window"

Make sure your batteries are charged. Measure the battery voltage on each battery (positive to negative) and from the front battery negative to the back battery positive (write down the results). Then measure voltage at all the points warthog notes and write down those results. Post them here when you have minute.

Have you removed, cleaned and reconnected the ground connections from the driver's side alternator to the engine, the front battery negative to the engine and the front battery negative to the chassis (right in front of that battery on the radiator support)?

Electrical things need a complete circuit from the battery positive to the battery negative. These trucks are negative ground systems so many items use the vehicle chassis to complete the circuit back to the battery negative. Many electrical problems can be traced back to missing or faulty ground (negative) connections.

 

[wiccantoy]

Ok went to the 1009 and checked it all out and it seems both stay on the whole time as it aparently is supposed to. Just never really noticed i guess.

 

[jhyatt7]

1

 

[wiccantoy]

Ok did more testing. Batts sit 14.4 but alarming things were drivers alt was showing 137 amps draw at idle with a lot on. Aka lights, heater, 4 ways, and my light bar on. All the items that will be getting used when I am out plowing. Also red wire going from front battery to the junction block than to the drivers alt is showing a 7/10 amp drop. Which is quite a lot for the short trip. This is also verified by the person who was helping me who owns a alt and starter rebuild shop. He just rebuilt my mep-701a gen starter for $200.00 .