Page 1 of 2 12 LastLast
Results 1 to 20 of 36

Thread: Alt. not charging

  1. #1
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Alt. not charging

    Hi all

    Brand new 120A alt from Rock Auto. The power and ground feeds check out, but there is no voltage at the field wires. System voltage with the car running is 12.xx until the battery runs down. I had it down to 11.87 and the car was still running with no noticeable problems. Oops.

    Tonight was supposed to be the night I broke the engine in properly, but then this came up.

    Assuming no broken wires or unplugged connectors, what are the possible causes and solutions to this problem? Also, the check engine light is on but the only codes it throws are 12 and 55.

  2. #2
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    So here is what I've found:

    The alt power and ground lines are fine. The power module to alternator lines are fine. The logic module to power module lines are fine. The only problem I can find is that the logic module doesn't put out anything on the voltage regulation line when the car is running. Sometimes when the car is off it will put out between 5 and 8 volts, but as soon as I start the car is drops to 0.01 volts. I even popped it out of the case and checked the voltage at the pin on the circuit board itself.

    Sounds like whatever drives the voltage regulator in the logic module died? There are no error codes though. I think the check engine light from before was the "flash CEL when knock" mod on the calibration I'm running. It went away after the lifters bled themselves out some and the pistons warmed up.

    Has anyone successfully repaired the LM voltage regulator before? Or should I find a new LM or pop in an external regulator?

  3. #3
    Buy my stuff!!!!!!!!!!! :O) Turbo Mopar Vendor turbovanmanČ's Avatar
    Join Date
    Dec 2005
    Location
    Abbotsford, BC
    Posts
    44,167

    Re: Alt. not charging

    The PM does all the work for the alt, so assuming all the powers and grounds check out, you need another PM or use an external voltage regulator. I don't think anyone has repaired the internal one due to PM"s being so cheap and plentiful but I guess that will change one day.
    1989 FWD Turbo Caravan-2.5 TIII, GT35R, auto, a/c, cruise, pwr windows/locks, fully loaded with interior and ran with full exhaust. RETIRED FOR A FEW YEARS! 12.57@104 :O)
    1984 Chev Getaway van, 6.2 Diesel with a remote mounted turbo setup burning WMO-For sale.
    2003 GSW 2.0L TDI, auto, fully loaded, modified, 360K-wife's.
    2004 GSW TDI, 5 speed, fully loaded, modified.

    Aurora ignition wires for sale. Link to info

    Super60 roller cams or custom/billet cams. Link to info

  4. #4
    Hybrid booster
    Join Date
    Feb 2007
    Location
    mid-atlantic
    Posts
    933

    Re: Alt. not charging

    Not to hijack your thread, but can you provide a link or p/n for that new alternator? Been looking for a new 120 alternator, but didn't see one from Rock Auto.

  5. #5
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    Quote Originally Posted by neongary View Post
    Not to hijack your thread, but can you provide a link or p/n for that new alternator? Been looking for a new 120 alternator, but didn't see one from Rock Auto.
    Found it listed under 88 Shelby Z. Rock Auto P/N 1866010. 120a Beck/Arnley. Wholesaler closeout - 5 remaining. $41.99 with no core charge. 30 Day warranty.

    The one I bought got shipped to me in its original box with very little packing material and the plastic cover plate was cracked from being banged around. I thought about sending it back, but its only cosmetic and it seems to work fine.

  6. #6
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    Quote Originally Posted by turbovanman View Post
    The PM does all the work for the alt, so assuming all the powers and grounds check out, you need another PM or use an external voltage regulator. I don't think anyone has repaired the internal one due to PM"s being so cheap and plentiful but I guess that will change one day.
    I know the PM does the actual work, but I think I meant to ask if anyone has tried repairing the part of the LM that tells the PM what to do. I suppose it doesn't matter.

    I putzed with it a while tonight and found that the LM will send the PM around 5v in a key on/engine off state, but as soon as the engine is running it stops sending the regulation signal. I can't tell if the actual regulator circuit in the PM works or not as I don't have a handy way to send it the proper regulation signal with the car running. I tried another PM I found in the shed, but the car wouldn't even start with that one.

    I also went junkyarding today looking for an external voltage reg and connector. The only thing I came up with was a 4-wire ford regulator off a 78 F150. I couldn't figure out how to adapt it though. I guess I'll buy a new dodge regulator and rig together some sort of connector temporarily until I can find a real one.

  7. #7
    Buy my stuff!!!!!!!!!!! :O) Turbo Mopar Vendor turbovanmanČ's Avatar
    Join Date
    Dec 2005
    Location
    Abbotsford, BC
    Posts
    44,167

    Re: Alt. not charging

    Quote Originally Posted by iangoround View Post
    Found it listed under 88 Shelby Z. Rock Auto P/N 1866010. 120a Beck/Arnley. Wholesaler closeout - 5 remaining. $41.99 with no core charge. 30 Day warranty.

    The one I bought got shipped to me in its original box with very little packing material and the plastic cover plate was cracked from being banged around. I thought about sending it back, but its only cosmetic and it seems to work fine.
    Bummer, too bad its a Bosch type unit,

    Quote Originally Posted by iangoround View Post
    I know the PM does the actual work, but I think I meant to ask if anyone has tried repairing the part of the LM that tells the PM what to do. I suppose it doesn't matter.

    I putzed with it a while tonight and found that the LM will send the PM around 5v in a key on/engine off state, but as soon as the engine is running it stops sending the regulation signal. I can't tell if the actual regulator circuit in the PM works or not as I don't have a handy way to send it the proper regulation signal with the car running. I tried another PM I found in the shed, but the car wouldn't even start with that one.

    I also went junkyarding today looking for an external voltage reg and connector. The only thing I came up with was a 4-wire ford regulator off a 78 F150. I couldn't figure out how to adapt it though. I guess I'll buy a new dodge regulator and rig together some sort of connector temporarily until I can find a real one.
    Hmm, interesting.

    What about just getting some or a resistor to knock the voltage down to 5 volts and apply it to the PM sense wire.
    1989 FWD Turbo Caravan-2.5 TIII, GT35R, auto, a/c, cruise, pwr windows/locks, fully loaded with interior and ran with full exhaust. RETIRED FOR A FEW YEARS! 12.57@104 :O)
    1984 Chev Getaway van, 6.2 Diesel with a remote mounted turbo setup burning WMO-For sale.
    2003 GSW 2.0L TDI, auto, fully loaded, modified, 360K-wife's.
    2004 GSW TDI, 5 speed, fully loaded, modified.

    Aurora ignition wires for sale. Link to info

    Super60 roller cams or custom/billet cams. Link to info

  8. #8
    Garrett booster
    Join Date
    Feb 2008
    Location
    Orange, CA
    Posts
    200

    Re: Alt. not charging

    This is what I did to my old GLH-S when the voltage regulator went out. Worked great, and if you want paint the VR black before you install it, so it won't stand out so much.
    if that doesn't work, here's a linkhttp://picasaweb.google.com/lh/photo...eat=directlink

  9. #9
    Buy my stuff!!!!!!!!!!! :O) Turbo Mopar Vendor turbovanmanČ's Avatar
    Join Date
    Dec 2005
    Location
    Abbotsford, BC
    Posts
    44,167

    Re: Alt. not charging

    Make sure you leave spot on the reg as it uses the case for a ground,
    1989 FWD Turbo Caravan-2.5 TIII, GT35R, auto, a/c, cruise, pwr windows/locks, fully loaded with interior and ran with full exhaust. RETIRED FOR A FEW YEARS! 12.57@104 :O)
    1984 Chev Getaway van, 6.2 Diesel with a remote mounted turbo setup burning WMO-For sale.
    2003 GSW 2.0L TDI, auto, fully loaded, modified, 360K-wife's.
    2004 GSW TDI, 5 speed, fully loaded, modified.

    Aurora ignition wires for sale. Link to info

    Super60 roller cams or custom/billet cams. Link to info

  10. #10
    Hybrid booster
    Join Date
    Feb 2007
    Location
    mid-atlantic
    Posts
    933

    Re: Alt. not charging

    Quote Originally Posted by iangoround View Post
    Found it listed under 88 Shelby Z. Rock Auto P/N 1866010. 120a Beck/Arnley. Wholesaler closeout - 5 remaining. $41.99 with no core charge. 30 Day warranty.

    The one I bought got shipped to me in its original box with very little packing material and the plastic cover plate was cracked from being banged around. I thought about sending it back, but its only cosmetic and it seems to work fine.
    That's not a new unit....it's a reman.

  11. #11
    Hybrid booster
    Join Date
    Feb 2007
    Location
    mid-atlantic
    Posts
    933

    Re: Alt. not charging

    Quote Originally Posted by turbovanman View Post
    Bummer, too bad its a Bosch type unit,
    It's a Chrysler unit, not Bosch.

  12. #12
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    So today I bought a dodge external regulator. I think the listing was for a 86 ramcharger or something. Got it wired in and I now have 14.78V at the battery! That seems a little high to me, but the battery is also probably pretty discharged so the regulator may be working overtime to bring the battery voltage up. I threw my charger on it and I'll start it up again later to see if the charge voltage goes down any. If not, is 14.7 too high or am I safe?

  13. #13
    Hybrid booster Turbo Mopar Contributor
    Join Date
    Apr 2010
    Location
    United States
    Posts
    437

    Re: Alt. not charging

    14.7 is stoic.

    Oh wait, that's air/fuel not charging volts!!

    14.7 is a little high. Not sure if it would be enough to damage a battery, but everything else SHOULD be fine.

  14. #14
    We Todd D dot D Turbo Mopar Staff sdac guy's Avatar
    Join Date
    Dec 2005
    Location
    Near Detroit MI
    Posts
    4,576

    Re: Alt. not charging

    Quote Originally Posted by iangoround View Post
    So here is what I've found:

    The alt power and ground lines are fine. The power module to alternator lines are fine. The logic module to power module lines are fine. The only problem I can find is that the logic module doesn't put out anything on the voltage regulation line when the car is running. Sometimes when the car is off it will put out between 5 and 8 volts, but as soon as I start the car is drops to 0.01 volts. I even popped it out of the case and checked the voltage at the pin on the circuit board itself.

    Sounds like whatever drives the voltage regulator in the logic module died? There are no error codes though. I think the check engine light from before was the "flash CEL when knock" mod on the calibration I'm running. It went away after the lifters bled themselves out some and the pistons warmed up.

    Has anyone successfully repaired the LM voltage regulator before? Or should I find a new LM or pop in an external regulator?
    According to the Instructors Guide (and the FSM wiring diagrams) there should be 12v on one of the field wires anytime the ignition switch is in the run position. This is a direct connection from the ignition switch to the J2 power feed, to the alternator.

    The power module adjusts the amount of ground that goes on the other field terminal lead via the built in voltage regulator.

    If you don't have the 12v present on the alternator field coil when the ignition switch is in the run position it is not a voltage regulator or LM/PM problem. It is a wiring problem.

    Barry
    86 Shelby Lancer Prototype
    90 Daytona Shelby VNT
    91 Spirit R/T



    For your questions about SDAC, please contact BadAssPerformance


  15. #15
    Buy my stuff!!!!!!!!!!! :O) Turbo Mopar Vendor turbovanmanČ's Avatar
    Join Date
    Dec 2005
    Location
    Abbotsford, BC
    Posts
    44,167

    Re: Alt. not charging

    Quote Originally Posted by neongary View Post
    It's a Chrysler unit, not Bosch.
    Close enough, lol.

    Quote Originally Posted by iangoround View Post
    So today I bought a dodge external regulator. I think the listing was for a 86 ramcharger or something. Got it wired in and I now have 14.78V at the battery! That seems a little high to me, but the battery is also probably pretty discharged so the regulator may be working overtime to bring the battery voltage up. I threw my charger on it and I'll start it up again later to see if the charge voltage goes down any. If not, is 14.7 too high or am I safe?
    That's fine.

    Quote Originally Posted by sdac guy View Post
    According to the Instructors Guide (and the FSM wiring diagrams) there should be 12v on one of the field wires anytime the ignition switch is in the run position. This is a direct connection from the ignition switch to the J2 power feed, to the alternator.

    The power module adjusts the amount of ground that goes on the other field terminal lead via the built in voltage regulator.

    If you don't have the 12v present on the alternator field coil when the ignition switch is in the run position it is not a voltage regulator or LM/PM problem. It is a wiring problem.

    Barry
    Correct.
    1989 FWD Turbo Caravan-2.5 TIII, GT35R, auto, a/c, cruise, pwr windows/locks, fully loaded with interior and ran with full exhaust. RETIRED FOR A FEW YEARS! 12.57@104 :O)
    1984 Chev Getaway van, 6.2 Diesel with a remote mounted turbo setup burning WMO-For sale.
    2003 GSW 2.0L TDI, auto, fully loaded, modified, 360K-wife's.
    2004 GSW TDI, 5 speed, fully loaded, modified.

    Aurora ignition wires for sale. Link to info

    Super60 roller cams or custom/billet cams. Link to info

  16. #16
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    Quote Originally Posted by sdac guy View Post
    According to the Instructors Guide (and the FSM wiring diagrams) there should be 12v on one of the field wires anytime the ignition switch is in the run position. This is a direct connection from the ignition switch to the J2 power feed, to the alternator.

    The power module adjusts the amount of ground that goes on the other field terminal lead via the built in voltage regulator.

    If you don't have the 12v present on the alternator field coil when the ignition switch is in the run position it is not a voltage regulator or LM/PM problem. It is a wiring problem.

    Barry

    Thanks for the info. If I remember what I was doing last night, there weren't any continuity problems I could find between the PM and alt. I might go back through and see if I can find the problem just for giggles, but at least for now it is running correctly on an external regulator.

    If the charge voltage doesn't come down I'll double check to make sure the regulator is seeing true battery voltage off my J2 splice. I suppose 14.7 isn't terrible though...

  17. #17
    We Todd D dot D Turbo Mopar Staff sdac guy's Avatar
    Join Date
    Dec 2005
    Location
    Near Detroit MI
    Posts
    4,576

    Re: Alt. not charging

    Quote Originally Posted by iangoround View Post
    Thanks for the info. If I remember what I was doing last night, there weren't any continuity problems I could find between the PM and alt.
    The problem will not be between the PM and alternator. The problem will be between the J2 power feed and the alternator. Just turn the key to the on position and see where the 12v ends on the J2 (why it doesn't make it to the alternator).

    Barry
    86 Shelby Lancer Prototype
    90 Daytona Shelby VNT
    91 Spirit R/T



    For your questions about SDAC, please contact BadAssPerformance


  18. #18
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    Quote Originally Posted by sdac guy View Post
    The problem will not be between the PM and alternator. The problem will be between the J2 power feed and the alternator. Just turn the key to the on position and see where the 12v ends on the J2 (why it doesn't make it to the alternator).

    Barry
    There is/was 12v at the alt with the key on. Maybe I was over complicating things and I just have a PM with a bad regulator in it. To rig up the external regulator I tapped in to the J2 feed at the alt harness and moved the R3 pin from that connector to the external regulator.

    It is still charging around 14.78v. I noticed there is about a 0.2v difference between battery voltage and the J2 feed at the external regulator. Could that account for the slightly higher charge?

    I'm going to go through and clean all the connectors and re-apply dielectric grease. Perhaps that will change something, maybe not. Not a bad thing to do anyway on a 24 year old car I suppose.

    I still can't figure out why the check engine light is on though. It only gives me code 12 and 55. I'll disable the CEL on knock in the cal first and see if it goes away, but I unplugged the knock sensor and it didn't seem to make a difference.

  19. #19
    We Todd D dot D Turbo Mopar Staff sdac guy's Avatar
    Join Date
    Dec 2005
    Location
    Near Detroit MI
    Posts
    4,576

    Re: Alt. not charging

    Quote Originally Posted by iangoround View Post
    Hi all

    Brand new 120A alt from Rock Auto. The power and ground feeds check out, but there is no voltage at the field wires. ....
    Okey dokey, I was going by this statement from your first post. In another post I thought you mentioned that you had 12v on the field wires with the switch on, but with the engine running you did not. Be sure that your ignition key is returning all the way to the run position after releasing it from start. I've had keys stuck in between positions and got flaky power problems from that.

    Reading more from the "Instructor's Guide", there are a few conditions related to the alternator and charging circuit that will turn on the power loss lamp. Some of them set code 16 and some do not. Some conditions that set code 16 erase it when the key is turned off, and it says there are instances when the code cannot be read by a DRB (or other means?).

    So, it sounds like the LM is recognizing there is a problem with the charging circuit and turning on the lamp.

    Barry
    86 Shelby Lancer Prototype
    90 Daytona Shelby VNT
    91 Spirit R/T



    For your questions about SDAC, please contact BadAssPerformance


  20. #20
    boostaholic
    Join Date
    Nov 2006
    Location
    Rochester, New York, United St
    Posts
    1,148

    Re: Alt. not charging

    Quote Originally Posted by sdac guy View Post
    Okey dokey, I was going by this statement from your first post. In another post I thought you mentioned that you had 12v on the field wires with the switch on, but with the engine running you did not.
    I think I initially tested it with the engine running. I did have 12v at the field terminals in a key on/engine off state last night. I think for giggles I'm going to go out and hook it back up to stock and see what happens.

    Quote Originally Posted by sdac guy View Post
    Be sure that your ignition key is returning all the way to the run position after releasing it from start. I've had keys stuck in between positions and got flaky power problems from that.
    I'll make sure to check that. This steering column is a wobbly tilt one, and I have had it apart in the past in an attempt to fix that. I may have put something back together wrong. The car has been garaged for a loooong time while I built this engine.

    Quote Originally Posted by sdac guy View Post
    Reading more from the "Instructor's Guide", there are a few conditions related to the alternator and charging circuit that will turn on the power loss lamp. Some of them set code 16 and some do not. Some conditions that set code 16 erase it when the key is turned off, and it says there are instances when the code cannot be read by a DRB (or other means?).
    Well that just plain isn't helpful at all. Would you mind scanning some of those pages so I can look at them?

    Quote Originally Posted by sdac guy View Post
    So, it sounds like the LM is recognizing there is a problem with the charging circuit and turning on the lamp.


    Barry
    Well, I know that all of the wires going to and from the LM, PM, and alternator are good. I was thumbing through my FSM and came across a few test procedures. I don't have it in front of me right now but I think it said something along the lines of jumping power from somewhere to the voltage regulation signal line at the LM. If the voltage goes up, the problem is at the LM. If not, it's someplace else. I may try that and see what happens. I did accidentally forget to unhook the battery and computer when I was doing some welding on the passenger side floorpan...

Page 1 of 2 12 LastLast

Similar Threads

  1. Charging problems PLEASE HELP
    By 87yorker in forum "I need help!"
    Replies: 19
    Last Post: 06-29-2010, 09:44 AM
  2. weird charging problem
    By LaserGurl in forum Electrical & Fuel System
    Replies: 1
    Last Post: 12-23-2009, 08:29 PM
  3. HELP! Charging issue 85 600ES...
    By carguyray in forum The Original "Turbo Dodge" Cars
    Replies: 4
    Last Post: 11-25-2009, 04:28 PM
  4. Rad Fan Fuse Kills Charging System????
    By Whorse in forum Electrical & Fuel System
    Replies: 0
    Last Post: 05-12-2008, 12:27 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •