AutoZone told me that they don't have a scanner for my truck. It's New Mexico after all! I hate to take it to the dealer because of the insuing sexual assault! This one has me baffles for sure. I will try to find the voltage in wire from the schematics and stick a voltmeter on it when it's doing it's thing.......

 

They're stupid. Ask them if they have a scanner for a '93 Dodge minivan. I have an el cheapo scanner (Auto X-Ray) that talks to mine.

 

Well, the truck was charging sometimes, the needle would all of the sudden snap back up to it's normal position, then it quits charging, and the needle falls back to 12 volts, then lower, then my radio quits and I know it's only a matter of time before the fuel cutoff soleniod closes. I had to limp her home. Interestingly the air conditioning compressor stayed engaged. I checked the CPS connections, battery connections, etc. and can't see anything obvious. I think the computer might be dying.

 

Latest in the saga...
I was looking at the Diesel Schematic and notices that the Water sensor is connected to the CPS, and my light has been on for quite a while, despite replacing the sensor on the fuel filter.
Does anyone have the ohm values for each wire of the Hall Effect (CPS)? I'm thinking at least one wire is dead.
Thanks,
Mark

 

If you check a Hall Effect sensor with an ohm meter you will render the sensor useless. You have to check them with a volt meter while in the circuit.

 

Got it. I will check it with the engine running to see if there is any output.
I have been driving around on an overnight charge trying to keep the AMPs down like "Apollo 13"! That is, no air, no radio, hand signals, no radar detector, nothing! It's still better than driving around in the spare car!

 

I got the codes pulled by a local shop (for 5 bucks!) and it threw three:
11
41
47

This does not really help me becausemy air and cruise are working. I swapped relays, still no charge. If I pull the block off the back of the alternator and grounded one of the field wires and hooked the other to the battery and it charges. If I hook the stuff back up it chages but only for a min or so.

I can't tell if it's intermittent brush issues or the PCM regualtor. I guess I'm pulling the Alt. and getting it checked.......

I'll do the external regulator workaround if the alt is OK.

Am I missing anything?????

 

If the codes mean the same as what it is for my truck,

11 (if the same as 12)= means the battery was disconnected in the last 50 key on cycles.

41= Generator field not switching properly; Open or shorted condition detected in the generator field control circuit.

47= Charging system voltage too low; batt voltage sense input below target. Also no sigificant change detected in battery voltage during active generator output circuit.

 

Actually yours is a DRBII and mine a DRBI.
My 11 is "No crank reference signal at PCM"
The other two are the same though.
Thanks!

 

Checked my FSM again. 11 is the same. I looked at the wrong one.

I wonder if there is a ground problem somewhere.

 

I checked everything, I think. I even tried direct ground to the battery.

 

I guess we are down to the alternator itself or the PCM, if it controls the voltage output.

 

Mark, I think your problem may be a bad connection at the PCM. Unplug the PCM and look at the pins and terminal ends, if you see any grungy ones clean them. Sometimes just disconnecting and reconnecting a plug will clean off the oxidation and give you a good connection.

Since the alt. charges when you full-field it, it's not the problem.

 

Thanks Dave, that's one thing I haven't tried.
The problem is it quits even if I bypass the PCM....

 

Ah, I missed that part. If the alt won't charge full fielded, it is toast. Probably brushes.