Archived Charging Problems

[JCrank]

Can anyone provide troubleshooting advice for my 93 Cummins/Dodge 350 ?

I recently gapped the crank position sensor to . 050" in relation to the damper pulley, installed a new alternator, battery and fan belt. The system still is not charging. ANy suggestions what to look at next would be greatly appreciated.

THANKS

Jon 93 D350 4x2, Stock Cummins

 

[SRadke]

First place to look is connections. Be sure you have good contact at the battery posts as well as between the ground cable and the block. Dielectric grease is your friend You didn't mention a regulator... . is the regualtor in a 93 in the alternator or external?



-Scott

 

[JCrank]

I'm not sure if I have internal or external regulator. I'm going to read up some more tonight. I do know my battery connections and the ground connection to the block are nearly perfect.

 

[pwerwagn]

I have a 74 and although it is not the same this may help you. I have to replace the regulator fairly often. Its about 3"x4" on the firewall. the other problem I have is the connection at the alternator. I have to use connection maintenance compound (basically die-electric grease) on the connection to keep it working. I've also bought a new alternator once and it did not work at all, so make sure the alt is good. If you got an alternator with the one wire hookup (internal regulator) you sometimes have to rev the engine up to get the exciter to activate the alt and start charging the batt.

 

[JCrank]

I was talking to a technician at a local Auto Electric shop. He told me that there is possibly a chip in the PCM which has failed. He expalined how to check to see if this is the problem. If it is the problem, he can put me a chip in the alternator for $ 50-70 rather than the chip in the PCM for $300-400.

I'm going to do the test his weekend. I have a alternator with 3 terminals.

Jon

 

[tgbol]

If it is your pcm there is a way to use an earlier voltage regulator to control your alternator.

 

[RGuzzo]

check the y splice on the left front fender where 2 red #12wires are spliced to a #20 white resistor wire connects this was a problem I had with mine and others have also had It took me 2 solid days and nights to find and Im an electrican and a damn good one If I must say. The conn. might look good but corrsion gets into it and it breaks the conn.

 

[Paychk]

There is a plug that is located just in front of the first valve cover, this leads down to the sensor, check it for clean dry and tight. Put some dielectric grease on it and reconnect it. If the computer losses the RPM signal from the crank sensor it wont turn on the alternator. The computer is located behind the battery. Check for fault codes, turn key, on-off-on-off-on, "on" is the run position not start. It will flash the check engine light this sequence, flash short pause flash, longer pause between codes. code 11 = no crank reference signal, code 12 = battery disconnected, 55 = end of codes

 

[paccool]

You need to check the cruise and AC to see if they work. Usually when the ECM takes a dump these quit working as well. You can install an external voltage regulator but that won't fix any other problems that may exist. By the way, you can get a rebuilt ECM from dodge for about $230 or so. They don't make new ones anymore but the rebuilds look like new units.



The 92 amd 93 years had this problem, not sure about the 91's.

 

[JCrank]

Thanks everybody ! I'm going to do some troubleshooting this afternoon when I get finished with mowing the yard. If anyone knows how to test the crank position sensor let me know. I know it has been replaced on my truck, but I don't know if it is working.

Jon 93 D-350 Club Cab LE, dually,stock Cummins, auto transmission

 

[JCrank]

After working on my truck today, I've reached the following conclusions. Cruise and A/C are working. When a new crank position sensor was installed by the previous owner, the way they spliced the sensor wires together was sloppy. I redone the splices, soldering the connections and protecting with heat shrinks. Doing some testing we found that at the two terminals at back middle of alternator (one is ground and other is supposed to be battery voltage) there isn't a ground or battery voltage at these terminals. We made a jumper wire with a remote starter switch... when activating the remote switch ,thus grounding the ground terminal, the alternator is charging.

I have checked every connection that has been recommended here and found all connections to be OK visually. we checked wires for voltage and ground all the way to the PCM and everything checked out OK. Pulled the plug on the PCM, and found that connection to be fine. I am getting the following codes using the key on/off/on/off/on method : codes 11,12,41,55.

After I redone the splices on the wires for the CP Sensor, I was no longer getting the code 11. I continue to get code 12,41,55. I found out also that the voltage regulator is self contained in the PCM. Is there a way to check the PCM ? WHAT should I check next ?

 

[Paychk]

code 41 = generator field not switching properly

 

[JCrank]

I thought that code 41 was "auto shutdown relay" That is part of the PCM ? Can that be replaced separately ?

 

[Paychk]

We made a jumper wire with a remote starter switch... when activating the remote switch ,thus grounding the ground terminal, the alternator is charging.

code 42 is ASD relay



The key here is the above statement. The wire at the ground terminal is hooked to the computer. You need to do a continuity check and make sure it is good (no break or short) back to the connector at the computer, that will be pin 20. If the wire is good then the computer has taken a dump. Here is a diagram of the connector:



https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=3750&width=3



Also here is a schematic of all the connection to the computer:



https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=3751&width=4

 

[JCrank]

I guess the PCM has took a dump. We checked the continuity of both the green and the blue wire from the alternator all the way to the PCM plug.

 

[Paychk]

You can get refurb computers from your dodge dealer, I believe $299 or so. Also you can get them from Autozone or Advanced Auto, and others $ unknown.



PS Welcome to the TDR, come on down to the 1st Gen. forum and meet Guys/Gals

 

[Paychk]

JCrank



Come down to the 1st gen forum and post there about the dead computer, one other the other guys had the same problem and rewired with a stand alone regulator. He saved the cost of a computer.