xEryx

Hello guys,

Friend of mine had a guy jump start his 2010 C300 because he left his lights on. The other guy car must have had issues cause he had multiple system fail/short and I need help figuring out if this is likely dead fuses, control units or something else.

These are the 4 systems having problems attached.

Thanks.

Colin G

There is a specific procedure for boosting your friend should know about.


https://mbworld.org/how-tos/a/merced...our-car-387069


Maybe they didn't ground your friends car correctly while boosting and something shorted as the result.

the_indian_kid

I thought my car had a dead battery. We jumped it, and nothing worked. I found out my battery was still fully charged. My instrument cluster went nuts, car won't start, but the electronics work.

Keep me posted on if the car did the same thing, or what the issue ended up being.

Thank you.

Funkwagen

You can check the fuses first to see if anything was blown. Disconnect the battery and leave it overnight, reconnect in the morning and see if any faults go away

xEryx

Thanks funk, I was planning to disconnect the battery and also try my car's battery on his. Is it pretty obvious when a fuse is blown? I didn't see anything weird.

Moto_Guzzi

If the lights were left on, and it drained completely, have the battery tested with one of those electronic testers, quick and tell you if battery was damaged due to the total discharge. I will rule this out 1st, you do not want to continiue with a hurted battery.

Funkwagen

Sometimes it's a little hard to tell without shining a flashlight on them, but there'll be a break somewhere in the metal filament in them. You'll have to pull each of them out to inspect them, likely. The one on the left is intact in the picture

xEryx

Checked every fuse with a multimeter and they were fine. Disconnected the battery completed for about 20mins and after putting it back on the failed systems came back online. The only problems were 2-3 burned bulbs, he lucked out.