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Eric
Eric, Automotive Repair Shop Manager
Category: Dodge
Satisfied Customers: 29935
Experience:  20+ yrs. experience as repair shop manager and technician.
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Just changed alternator and still only producing about 10 volts

Customer Question

just changed alternator and still only producing about 10 volts on guage
JA: Sometimes things that you think will be really complicated end up being easy to fix with a Dodge. The Dodge Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so he can help you best.
Customer: codes p2149 p2146 p2502 p2503 p2509 p1755
JA: Are you hoping to fix this yourself?
Customer: yes
JA: Great! What have you tried so far?
Customer: just alternator so far
JA: Is there anything else important you think the Dodge Mechanic should know about your Dodge?
Customer: just started losing voltage went from 14 to 8 in a few miles so changed alternator worked for a day and then when you start engine it only gets to about 12 volts and slowly drops to almost 8 within a mile
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Dodge Mechanic about your situation and then connect you two.
Submitted: 7 months ago.
Category: Dodge
Expert:  Eric replied 7 months ago.
HI,Ok, voltage is controlled by the PCM(powertrain control module. either the PCM has failed on the field generator circuit or there is a break in the wiring between the PCM and the alternator. You will need a voltmeter for testing and I will need the year, model and engine size of your Dodge so that I can give you proper testing
Customer: replied 7 months ago.
2006 dodge ram 2500 slt 5.9 cummins
Expert:  Eric replied 7 months ago.
HI,Ok, on the diesel engine, it is the ECM(engine control module), located at lower left of the engine that controls the voltage via the field generator wire. On yours, it is a brown with grey striped wire at the connector for the alternator. You will disconnect the C1 connector at the ECM and the connector at the alternator. Set voltmeter to OHMs and place one lead on the pin at the brown/grey wire at the alternator connector and the other lead at the pin 7, brown/grey wire at C1 connector and check for resistance. See attachments for C1 connector location and pinout If no resistance - usually a reading of infinity on most voltmeters, then a break in the wiring and will need to be either traced and repaired or new wire run. If resistance is present, replace the ECM Please remember to rate service using the rating page so that I may receive credit. ThanksIf for any reason, you can't rate my answer OKAY, GOOD, or EXCELLENT today.Please reply and let me know why, so I can help more/better.All follow up responses are FREE, after completing the required rating
Customer: replied 7 months ago.
can't seem to locate ecm is it on the firewall
Expert:  Eric replied 7 months ago.
HI, It isnt on the firewall. As I previously stated, it is at the lower left of the engine. See the attachment Just noticed that the connector pinout for C1 connector did not attach. Here it is Please remember to rate service using the rating page so that I may receive credit. ThanksIf for any reason, you can't rate my answer OKAY, GOOD, or EXCELLENT today.Please reply and let me know why, so I can help more/better.All follow up responses are FREE, after completing the required rating
Customer: replied 7 months ago.
little nervous pulling ecm c1 one cover off will it just pry off dont want to break anything
Expert:  Eric replied 7 months ago.
HI,There should be an allen bolt in the center of the connector. You will need to remove it and then pull the connector.
Customer: replied 7 months ago.
ok someone also said check the alternator fuse do you know where i can find that thx
Expert:  Eric replied 7 months ago.
HI, Diesel engine doesnt have one. There is a fusible link on the brown with red striped wire going from the alternator to the battery. It is inline in the wire and closer to the battery than the alternatorI have attached the wiring diagram for charging system so that you can see it
Expert:  Eric replied 7 months ago.
Hi,I can tell you that this is a common issue on these engines and is about split 50/50 on it being the ECM or break in the wire going from it to the alternator - which why we need to do the simple test to check the wire Please remember to rate service using the rating page so that I may receive credit. ThanksIf for any reason, you can't rate my answer OKAY, GOOD, or EXCELLENT today.Please reply and let me know why, so I can help more/better.All follow up responses are FREE, after completing the required rating
Customer: replied 7 months ago.
Thx glad I'm talking to you than guy at advanced I am going to try your test and get back to you
Expert:  Eric replied 7 months ago.
HI,You are welcome and will be all day. Please remember to rate service using the rating page so that I may receive credit. ThanksIf for any reason, you can't rate my answer OKAY, GOOD, or EXCELLENT today.Please reply and let me know why, so I can help more/better.All follow up responses are FREE, after completing the required rating
Expert:  Eric replied 7 months ago.
I noticed we have not yet resolved your concern you asked about. I would sure appreciate it if you would reply so I can offer my skills and knowledge and repair guide access to help as best I can.~Do you still need more help?~Confused by my info request or answer?~Need more time?~Confused on how the site works?~Need more detail or a different explanation?If the answer is YES to any of these just press reply and lets work on this concern some more.If you have new questions now or in the future please do not hesitate to ask them. If you would like me to assist you. Just bookmark this page so you can access my profile easy and post a new question from the question box on my profile page.Please remember to rate service using the rating page so that I may receive credit. Thanks