Archived Help!!!

[DieselPuter]

I have a question for you guys.....



I have a hydro clutch pump that sits right above my alternator.



About a week ago my check guage light came on and volt meter went all the way down. I pulled over shut it down and restarted, volts were fine, tested at 13. 75 to 13. 98 the next day. A day later it did the same thing and I pulled over and tested with the guage all the way down and it tested good. It did it off and on for 2 more days and then yesterday I noticed that radio lights were dimming I pulled over and it checked at 9. 45. I shut it off and had it towed to dealership.



The dealership said the batteries tested fine, but the alternator was not charging. I asked the tech if it might be the ECM and not the alternator, he said no, the OBD II codes said the ECM was fine. So they R/R alternator, they call me today and now tell me its the J-Tech computer that is part of the transmission that is bad becasue of some hydro oil that leaked in to the alternator and "fried it". I could not see any oil in or around the alternator or on the hydro pump for that matter, its a new muncie pump thats been on for a year.



Any body know what a little hydro oil dripping on the alternator will do to it and what the heck is a J-Tech computer????????? Am I getting the screw job from the dealer, its my work truck and no truck = no work = no $$$



Thanks in advance

 

[Bigramguy]

I doubt a little oil would short out an alternator,that's if there even was an oil leak in the first place.



The alternator is controlled by the PCM,which is a DC part,mounted in the passengers firewall area.



The ECM,controls the engine,and is a Cummins part,is mounted on the side of the engine.



I would get them to double check stuff,as simple things like the alt fuse (in the PDC),grounds,etc,could be causing your problem.

 

[DieselPuter]

Thanks.....

One more question for ya bigramguy, have you ever heard of a J-Tech?? The dealer told me it was the computer that links the ECM and the PCM. Does that sound right??



I have a good friend that is a Master Ford Tech and he doesn't't think a little oil would cause any problems with the alternator either but he admits he doesn't know much about the CTD.

 

[Bigramguy]

Never heard of the J-Tech. Not on a Dodge CTD anyways. Maybe that's what the call the fancy machine they (the dealer) uses to connect to the PCM to get data ? I always thought it was a DRB II or something else.



Go to the dealer and get them to show you the oil INSIDE the alt,and explain what it did. It would have to have shorted out the field control circuit for it to do any damage to the PCM. Get them to measure the resistance of the rotor and field circuit,and to prove it 's shorted out.



I have seen quite a few PCM's that just died,and would not charge,but it was ONLY the PCM,and the alternator was fine. You can take the alt to any parts store and have it bench tested. You may find it's OK.



And again,double check everything else. Do a search,there were some goods threads about PCM ground problems,and the famous blown alt fuse,which is usually blown when changing the oil filter.



If it's going to be big bucks to fix all this stuff at the dealer,then take it home and bolt on a Leece-Neville alt,available at most truck shops. They are cheap,powerful,reliable,and NOT controlled by the stupid DC PCM. I went through all the crap when my stocker died,and found it was cheaper to upgrade it to something better. See a pic of mine below.

 

[Bob4x4]

The JTEC is a D/C acronym for the PCM. It stands for Jeep/truckengine controller. In all the years I have been working on these things I have only had to replace 2 alternators,they were both fried. You could smell as well as see the damage. You can disconnect the field wires and run the alternator just like we did in pre computor control days,to test one field wire hot,the other a ground control. Good luck.

Bob

 

[bubba_zanetti]

I had very similar symptoms.



Check engine lights, tach drops to zero, voltage drops...



Mine was the connector between the engine speed sensor on the front dampener pulley and the engine wiring harness.



Right behind the upper radiator hose is a small 3 wire connector. Mine had corrosion. I WD-40'd it and reattached... works fine now.



In my case, if the engine speed is not sensed then the alternator will not turn on to charge.

 

[DieselPuter]

Follow up.....

I was able to talk to the tech who worked on my truck, he really didn't have much to say and the service advisor interrupted us several times. The alternator did have a small amount of oil on it and in it, I sprayed with degreaser and hosed it clean.



He replaced the PCM and the alternator. I was given both parts back after some heated disscussion, don't think they wanted me to have them for whatever reason. I am going to have the alternator tested, does anyone know how to test the PCM to see if it is fully working??? I think I get hosed by the ste..... oops Dealer... ... ... .

 

[Josparkz]

I'm going to put my $. 02 in here. I have gotten alternators soaked with water , which is electrical conductive , and never had a problem. I'm thinking that certain types of oil are used as insulators and flash suppressant material in certain types of high voltage electrical gear. If my memory serves me well , I believe conductors are in contact with the oil. That would make me think that oil is considerable less conductive than water , and would not short it out.

It could prevent the brushes from getting good contact . Fifty cents worth of contact cleaner would fix that.

I know I smoked that main fuse that is in that box under the hood once. I though I had smoked the alternator till I studied the owners manual. Anyhow , I may be wrong on this , but It sounds good in theory to me right now.

 

[DieselPuter]

Agree

Josparkz, I totaly agree. Every day my truck is down I lose about $2000. 00 in revenue. I didn't have the time ($$) to go round and round with the dealer. I think I can hook the old PCM back up and see if the problem returns. I am having a alternator shop tomorrow look at the one they replaced. So we'll see... ... ...

 

[Sticks]

Good job in getting your old parts back... . presuming they actually came off your truck.



I have seen an alt go bad when it was soaked in oil, but it took near 6 months to cook (not my truck, not my problem, he was warned). I have also seen about 10 alt problems cured by cleaning all the connections to the alt, batteries, and the ground points.



Keep us informed with the results of the alt test and the PCM