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Marty, Bosch Certified Technician
Category: Transmissions
Satisfied Customers: 53981
Experience:  Bosch certified master technician. Over 35 years experience.
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I have a 1978 450sl and I replaced my starter but when I

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I have a 1978 450sl and I replaced my starter but when I went to hook up the battery it tried to crank so I believe I hooked the wires up wrong and bypassed the selinoid so I switched the wires and went to turn the key and no charge light no accessory lights as if I had not turned the key I checked all my fuses and ground lines all in good shape.did I some how damage something by hooking up the starter wrong or is it an underling problem? Any help would be greatly appreciated
JA: Does the battery look like it's leaking? And does it have a strong smell -- like sulfur?
Customer: No it dose not it is a fairly new battery
JA: What is the model of your '78 Mercedes?
Customer: 450sl
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: I just told you what I tried
JA: Anything else you want the mechanic to know before I connect you?
Customer: No

Hi, my name is***** am not following your question. You stated "when I went to hook up the battery it tried to crank so I believe I hooked the wires up wrong". Are you saying that the starter cranked the motor but the motor would not fire?

Customer: replied 8 months ago.
After I installed the starter, With the key out of the ignition i touched the negative lead to the battery It started to crank so I pulled the lead away it did not fire is that due to improper installation?

If it tried to crank as soon as you connected the battery and the key was in the off position it sounds like you have the big battery cable shorted to the lower solenoid lug or to the small solenoid wires or the starter is defective. The big battery cable connects to the upper lug of the solenoid and cannot be touching the lower lug or the other wires.

Let me know if you have any questions. Please remember to rate my service :-)


Customer: replied 8 months ago.
Ok so that is how the starter is hooked up now I double checked and Still when I turn the key no power I don't hear the fuel pump kick on and no dash lights come on radio and accessories do not work would shorting the starter cause that and how would I repair the issue ?

Sounds like you have no power to the ignition switch. Remove and inspect all of the fuses. Fuse #1 should provide power to the ignition switch but remove and inspect all of the fuses.

Sorry that last reply was incorrect. The ignition switch gets power directly from the big cable that connects to the starter. Looking at the diagram there should have been two big wires going to the starter. Are you sure you have both connected together to the upper terminal on the solenoid?

Customer: replied 8 months ago.
there are two the bigger one is on the top the power wire I believe

If you disconnected two larger wires from the old starter they both need to be connected together and attached to the top lug on the starter solenoid.

Customer: replied 8 months ago.
Ok thank you I miss understood all switch it

You're quite welcome. Let me know if you need anything else. Please don't forget to rate my service.


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