Hello all!
I have a 1992 500E inside the shop that has an issue starting. I removed the rear seat and pulled the fuel pump relay out. Used a jumper wire and bypassed the relay. The car starts fine and runs perfect while the jumper wire is in place. If you quickly remove the wire and install the relay, it will begin to chatter as if its not getting enough power or it doesn't have sufficient ground. If you cut the car off, it will not restart without the fuel pump being hard wired through the plug. Basically pin 87 and 30.
The car was driven in but the performance was low due to one of the fuel pumps being defective. I replaced both fuel pumps and filter. I believe the extra current draw from both pumps working now or the possible low current to activate the field inside the relay to be the problem.
I now longer have any of my older wiring diagrams for the 124 chassis so I'm not sure where to go from here. Trying to figure out where the power comes from to activate the relay or is the relay triggered by adding the ground signal. Has anyone ran into this issue before?
I have a 1992 500E inside the shop that has an issue starting. I removed the rear seat and pulled the fuel pump relay out. Used a jumper wire and bypassed the relay. The car starts fine and runs perfect while the jumper wire is in place. If you quickly remove the wire and install the relay, it will begin to chatter as if its not getting enough power or it doesn't have sufficient ground. If you cut the car off, it will not restart without the fuel pump being hard wired through the plug. Basically pin 87 and 30.
The car was driven in but the performance was low due to one of the fuel pumps being defective. I replaced both fuel pumps and filter. I believe the extra current draw from both pumps working now or the possible low current to activate the field inside the relay to be the problem.
I now longer have any of my older wiring diagrams for the 124 chassis so I'm not sure where to go from here. Trying to figure out where the power comes from to activate the relay or is the relay triggered by adding the ground signal. Has anyone ran into this issue before?
