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  • Writer's pictureKulAdventures

Dodge Sprinter Alternator Replacement on the Road

Updated: Apr 26, 2019

During my last trip through the pacific northwest I was driving my 2004 Dodge Sprinter on a road trip and I started having issues with my alternator and voltage. The van had been fine for 30-40hrs of on the road driving. Parked for 2 hours, restart and the battery light is on, scangauge shows 12.2 volts with engine running. I drive it a bit, turn it off restart, drive, still showing the battery light and just over 12 volts. This is a clear indicator that my alternator has failed.

I'm an hour from an auto parts store (Olympic National Forest) so I drive it using the rear battery (200ah battery) and solar (200w system) to keep engine voltage above 12v, which works (I can force a connection between house and engine battery, very important). I know a diesel will not pull as much voltage as a gas engine, however eventually my fuel pump will quit and I will be stranded until I have more sunlight. I pull into town after an hour of driving at 12.0-12.2v and I hear a whirling type of noise and the voltage jumps back up to 13.8 and everything is good to go. I am not confident this wont come back so I try to purchase a new alternator, just in case. However that NAPA did not have it, so 2 more hours down the road I get to an auto parts store that has the 150amp alternator that I need and I set out to repair it in the auto stores parking lot:


-150 Amp Alternator (Cheap one that I got stuck with, OE Bosch One)


-10mm socket and 3/8" socket wrench

-10mm box wrench

-13mm socket

-E-12 External Torx Socket (Use this over 1/4" socket to avoid stripping the bolts)

-1/4" open end wrench (optional, but helpful)

-17mm socket (12 point)

The process is pretty straightforward and totally doable in a parking lot. Due to the height of the vans you can get under them without a jack/lift.

1. Remove battery negative cable and move the disconnect wire away from battery terminal

2. Remove the serpentine belt from the alternator using a 17mm socket on the tensioner (I have replaced my tensioner and a 17mm socket works, some report that a 3/8" drive socket wrench will work by itself). I did not lock open the tensioner as many do, I just took it off the alternator and set at aside, while still on the other pulleys. Just remember the correct routing when removed.

3. Remove turbo heat shield (10mm bolts) then remove the hose connecting the turbo and turbo resonator (hose clamp)

You can see the E12 Torx in the center of this picture holding the alternator on

4. Disconnect all wires from the alternator with 8mm and 13mm socket and set aside (confirm that battery is disconnect prior to doing this)

5. Remove alternator by removing all four E12 external torx bolts. Some people say you can use a 1/4" wrench to loosen the E12 torx bolts, which I tried, but when one started to strip I went back into the auto parts store and bought the E12. Maybe in my garage I would try it, but a stripped bolt means I am stranded. Not worth it. The top rear bolt is hard to get to. I used a combination of 3/8" open end wrench and 10mm sockets to loosen it. Its easier to get to once you remove the bracket held on by two of the other alternator bolts.

6. Remove the alternator and place new one in its place, bolting down the E12s, making sure to do the difficult top rear one first.

7. Reconnect alternator wires making sure the connection are clean and corrosion free. If not get some sand paper and clean them.

8. Reconnect turbo resonator and hoses

9. Reattach the serpentine belt with correct routing and using the 17mm socket as a tensioner.

10. Confirm the routing, connect the battery and start. Listen of any odd noises and check voltage. If over 13.8 volt you should be good to go.

This fixed my issue and I was back on the road. My old alternator was clearly bad and the decoupler/clutch was pretty jammed up and was not functioning correctly. The old alternator was also hard to turn.

Good video I referenced for the alternator replacement (not my video)

UPDATE April 2019: Alternator has failed again... pulled it off and looked at it and it appears fine. I am assuming since it was a cheap rebuilt one something went wrong inside. I will be replacing with OE Bosch 150A alternator now that I am not on the road.

Almost looks like the inside got rusted...

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