HELP! 2010 S63 Blowing Fuel Pump Fuse F21, Starter wont engage
10-30-2019, 09:13 AM
#1
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HELP! 2010 S63 Blowing Fuel Pump Fuse F21, Starter wont engage
ey guys, 2010 S63 having a few issues, long story short...
Took the vehicle in to my independent to have the infamous head bolts upgraded as preventative maintenance.
Install went fine, however afterwards car was throwing a CEL for running too lean. Smoke test determined one
of the valve cover gaskets was not seated correctly. My indy went ahead and replaced the gasket. Tested the
car on the lift and all seemed well.
An hour later went to pull the car up front for me to pick up and the car would not start. Dash lights up and everything
seems normal, however when you turn the key the starter does not engage. Ordered new Bosch starter and installed,
still nothing. If you ground out with a screwdriver, the starter engages. Obviously engine does not start because car
does not recognize we are jumping the starter.
Chasing wires/fuses/relays and we found when the key is turned, the starter is not getting power to turn on. We also
found one of the fuses in the Front SAM box (engine bay driver side) keeps blowing as soon as the car has power or
"wakes up." It is F21 (20amp) Circuit 87 - Fuel Pump Relay.
We have checked all other fuses and relays related to the fuel pump are in good working order, as well as checked for
burns on the fuse boxes. Also checked wiring on fuel pump as that was an issue for another member.
Anybody have any idea on where to go next as we cant seem to figure out this problem?
Why does F21 keep blowing fuses instantly? We tried 15/20/25/30A and they all blew as soon as installed.
Any and all help would be much appreciated!
Took the vehicle in to my independent to have the infamous head bolts upgraded as preventative maintenance.
Install went fine, however afterwards car was throwing a CEL for running too lean. Smoke test determined one
of the valve cover gaskets was not seated correctly. My indy went ahead and replaced the gasket. Tested the
car on the lift and all seemed well.
An hour later went to pull the car up front for me to pick up and the car would not start. Dash lights up and everything
seems normal, however when you turn the key the starter does not engage. Ordered new Bosch starter and installed,
still nothing. If you ground out with a screwdriver, the starter engages. Obviously engine does not start because car
does not recognize we are jumping the starter.
Chasing wires/fuses/relays and we found when the key is turned, the starter is not getting power to turn on. We also
found one of the fuses in the Front SAM box (engine bay driver side) keeps blowing as soon as the car has power or
"wakes up." It is F21 (20amp) Circuit 87 - Fuel Pump Relay.
We have checked all other fuses and relays related to the fuel pump are in good working order, as well as checked for
burns on the fuse boxes. Also checked wiring on fuel pump as that was an issue for another member.
Anybody have any idea on where to go next as we cant seem to figure out this problem?
Why does F21 keep blowing fuses instantly? We tried 15/20/25/30A and they all blew as soon as installed.
Any and all help would be much appreciated!
