Why is it not starting
Thread Starter
Newbie
Joined: Aug 2022
Posts: 14
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Eqs 450+, gle43, e55 Amg
Why is it not starting
My E55 was dead and the key didn’t do anything. When I connected a jump box or try to jumpstart with the car, the radio and everything will turn on, but when I tried starting it, I’d hear a pop from the engine bay every time I tried. What can it be? Can it still be the battery?
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Joined: Jan 2014
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From: Republic of Texas
'99 and '05 E55 AMG
How does the main battery under the rear seat test?
I use an older Solar BA5 battery tester on all of my car batteries. Works with Conventional, AGM, Gel Cell, and Spiral Wound Batteries. Provides voltage, Cranking Amps, and Cold Cranking Amps.
The AGM batteries I use in both my E55s are rated 900 CCA, usually test a bit over 1000 CCA when brand new, and when a battery dips below 600 CCA the battery gets replaced (beats the car not starting in a rest area between Fort Stockton and El Paso).
Pull an Amazon search on "Solar BA7 battery tester" and you will have multiple choices. Easier to test the battery in the car rather than pulling it out and carrying the battery to a automotive parts shop for testing.
When disconnecting the battery, or when connecting jumper cables or a new battery, do NOT have the key fob in the ignition. That runs the risk of damaging electrical modules.
Confirm your battery is good, then move to the engine compartment starter fuse and relay. If the starter still will not activate, you can purchase manually switched relays (Amazon search on "automotive relay bypass switches) that can be temporarily installed in lieu of the starter relay. You can then flip the switch to "on" for one or two seconds to confirm the starter solenoid is activating the starter. If that test is successful, that would indicate the signal to the starter relay is not being received. Further troubleshooting from there.
It's nothing but a yes/no decision tree.
The attached schematics are for a six-cylinder facelift E-class but had plenty of good information in them. Should point you in the correct direction.
I use an older Solar BA5 battery tester on all of my car batteries. Works with Conventional, AGM, Gel Cell, and Spiral Wound Batteries. Provides voltage, Cranking Amps, and Cold Cranking Amps.
The AGM batteries I use in both my E55s are rated 900 CCA, usually test a bit over 1000 CCA when brand new, and when a battery dips below 600 CCA the battery gets replaced (beats the car not starting in a rest area between Fort Stockton and El Paso).
Pull an Amazon search on "Solar BA7 battery tester" and you will have multiple choices. Easier to test the battery in the car rather than pulling it out and carrying the battery to a automotive parts shop for testing.
When disconnecting the battery, or when connecting jumper cables or a new battery, do NOT have the key fob in the ignition. That runs the risk of damaging electrical modules.
Confirm your battery is good, then move to the engine compartment starter fuse and relay. If the starter still will not activate, you can purchase manually switched relays (Amazon search on "automotive relay bypass switches) that can be temporarily installed in lieu of the starter relay. You can then flip the switch to "on" for one or two seconds to confirm the starter solenoid is activating the starter. If that test is successful, that would indicate the signal to the starter relay is not being received. Further troubleshooting from there.
It's nothing but a yes/no decision tree.
The attached schematics are for a six-cylinder facelift E-class but had plenty of good information in them. Should point you in the correct direction.
Last edited by bbirdwell; Dec 31, 2025 at 01:10 PM.
Thread Starter
Newbie
Joined: Aug 2022
Posts: 14
Likes: 1
Eqs 450+, gle43, e55 Amg
How does the main battery under the rear seat test?
I use an older Solar BA5 battery tester on all of my car batteries. Works with Conventional, AGM, Gel Cell, and Spiral Wound Batteries. Provides voltage, Cranking Amps, and Cold Cranking Amps.
The AGM batteries I use in both my E55s are rated 900 CCA, usually test a bit over 1000 CCA when brand new, and when a battery dips below 600 CCA the battery gets replaced (beats the car not starting in a rest area between Fort Stockton and El Paso).
Pull an Amazon search on "Solar BA7 battery tester" and you will have multiple choices. Easier to test the battery in the car rather than pulling it out and carrying the battery to a automotive parts shop for testing.
When disconnecting the battery, or when connecting jumper cables or a new battery, do NOT have the key fob in the ignition. That runs the risk of damaging electrical modules.
Confirm your battery is good, then move to the engine compartment starter fuse and relay. If the starter still will not activate, you can purchase manually switched relays (Amazon search on "automotive relay bypass switches) that can be temporarily installed in lieu of the starter relay. You can then flip the switch to "on" for one or two seconds to confirm the starter solenoid is activating the starter. If that test is successful, that would indicate the signal to the starter relay is not being received. Further troubleshooting from there.
It's nothing but a yes/no decision tree.
The attached schematics are for a six-cylinder facelift E-class but had plenty of good information in them. Should point you in the correct direction.
I use an older Solar BA5 battery tester on all of my car batteries. Works with Conventional, AGM, Gel Cell, and Spiral Wound Batteries. Provides voltage, Cranking Amps, and Cold Cranking Amps.
The AGM batteries I use in both my E55s are rated 900 CCA, usually test a bit over 1000 CCA when brand new, and when a battery dips below 600 CCA the battery gets replaced (beats the car not starting in a rest area between Fort Stockton and El Paso).
Pull an Amazon search on "Solar BA7 battery tester" and you will have multiple choices. Easier to test the battery in the car rather than pulling it out and carrying the battery to a automotive parts shop for testing.
When disconnecting the battery, or when connecting jumper cables or a new battery, do NOT have the key fob in the ignition. That runs the risk of damaging electrical modules.
Confirm your battery is good, then move to the engine compartment starter fuse and relay. If the starter still will not activate, you can purchase manually switched relays (Amazon search on "automotive relay bypass switches) that can be temporarily installed in lieu of the starter relay. You can then flip the switch to "on" for one or two seconds to confirm the starter solenoid is activating the starter. If that test is successful, that would indicate the signal to the starter relay is not being received. Further troubleshooting from there.
It's nothing but a yes/no decision tree.
The attached schematics are for a six-cylinder facelift E-class but had plenty of good information in them. Should point you in the correct direction.
thanks, I’ll let u know
