Stranded with blown fuse #16. w/ Added Info.

Howdy, fellow Sprinters,

Driving home on a dark deserted highway, my van suddenly died. I found that fuse #16 under the steering column was blown. Replaced it but it popped instantly when turning the key to position 2 (run).

Following the wiring diagram led me to C1 on the ECM, labeled as Engine Control Relay Output.

I unplugged C1 from the ECM and the fuse did not blow, but did blow when I plugged it back in.

The engine wiring harness is brand new less than 2 months ago. No evidence of damage anywhere on the harness.

I'm a long way from home, with limited resources. Any insights would be greatly appreciated!

Thanks in advance,
Marc

Re: Stranded with blown fuse #16. Ideas?

If only it were Fuse #17. Fuse #17 branches out everywhere.

It appears the #16 goes pretty much directly to the ECM aka ECU pins.

Some info is in these threads.

https://sprinter-source.com/forum/showthread.php?p=562418#post562418

https://sprinter-source.com/forum/showthread.php?t=31208

Sorry I can't offer more.

Good luck.

vic

Re: Stranded with blown fuse #16. Ideas?

What were the symptoms/cause of the wiring harness replacement?

--dick

Re: Stranded with blown fuse #16. Ideas?

Thanks, Vic, for those links. However, I managed to diagnose and repair the problem before I saw them.

Dick, I replaced the wiring harness because 1) There was significant, suspect chafing at the point near the fuel filter, and 2) lindenengineering's comments on the frequency with which he finds them in need of replacement.

The problem turned out to be a damaged cam sensor wire. When I replaced the injector cover after installing the new harness I inadvertently pinched the wires between the valve cover and the divider or stiffener inside the injector cover. The pinch turned into a short, causing engine shutdown and blowing fuse #16.

After I discovered that disconnecting C1 from the ECM stopped the fuse from blowing, I proceeded to test by unplugging all the connectors except C1 and then plugging them back in one at a time, turning the key to position 2 and observing the fuse. Out of an abundance of caution I disconnected the battery each time before plugging or unplugging a connector.

Finally I found that the fuse blew only when C4 was connected. Following the pinout in the service manual I examined each of the sensors that connector served. Thus I found the damaged cam sensor wires. Some 18 gauge wire and a few butt splices got me on the road again

Re: Stranded with blown fuse #16. Ideas?

FahrverSprinten said:

...

Finally I found that the fuse blew only when C4 was connected. Following the pinout in the service manual I examined each of the sensors that connector served. Thus I found the damaged cam sensor wires. Some 18 gauge wire and a few butt splices got me on the road again

Click to expand...

Good job. Thanks for the follow-up.

I know there's some training manual information which shows the various 12 volt and 5 volt outputs from the ECM aka ECU. I couldn't find that during my search yesterday.

vic

Added for future reference.

Re: Stranded with blown fuse #16. Ideas?

Added: