How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Marty Your Own Question
Marty
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53315
Experience:  Bosch Certified Master Tech. Over 35 years experience.
13230946
Type Your Mercedes Question Here...
Marty is online now
A new question is answered every 9 seconds

00 s430 know power to purple wire on starter
, sorry I

Customer Question

Customer: 00 s430 know power to purple wire on starter
JA: Thanks. Can you give me any more details about your issue?
Customer: sorry I got 12volt from switch but starter not engaging but jump it and car would run
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $18) to post your type of question to Mercedes Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: yes
JA: OK. Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, my name is***** you a technician? Do you have a Mercedes scan tool?

Customer: replied 1 year ago.
I a tech work at small shop I only a snap on Solus ultra
Customer: replied 1 year ago.
Car want start by key but I can jump the purple wire and it will run I really can't tell if the starter relay is bad
Customer: replied 1 year ago.
Does the starter relay powers that purple wire to the starter
Expert:  Marty replied 1 year ago.

Yes the relay powers the purple wire. Have you replaced the relay yet?

Expert:  Marty replied 1 year ago.

You can test for power to the relay by removing the relay and putting your voltmeter between terminal 85 and 86 in the relay box then turning the key and checking for 12V when the key is turned to the start position.

Expert:  Marty replied 1 year ago.

Are you still with me?

Customer: replied 1 year ago.
Ok I should have power on 85 and 86 when key is run position correct if not what's next
Customer: replied 1 year ago.
Is this starter relay 4 or 5 terminals making sure I am checking correct one
Expert:  Marty replied 1 year ago.

Your test is done with the key in the start position NOT in the run position.

Expert:  Marty replied 1 year ago.

The starter relay is the green relay in the passenger side fuse and relay box under the hood.

Expert:  Marty replied 1 year ago.

If you aren't getting 12V to the relay in the start position try disconnecting the electrical connector at the front of the transmission and see if it will start.

Customer: replied 1 year ago.
do you have wiring diagram for starting system I bought a relay from local part but know luck
Expert:  Marty replied 1 year ago.

I have schematics but I cannot post them here. I can send them to your private email for an additional service fee. Did you try disconnecting the electrical connector at the transmission then try starting the car?

Customer: replied 1 year ago.
that was a round plug but made know different would there be a different in the relay versus one from dealer
Expert:  Marty replied 1 year ago.

The starter relay is part number 002 542 76 19. As long as you purchased the correct part number it shouldn't make any difference. The usual problem on this model when you have no power to the starter is either a bad electrics plate in the transmission or a bad gearshift assembly or a bad transmission control unit. Basically the ECU does not get the message that the car is in park therefore it will not engage the starter.

Customer: replied 1 year ago.
Ok it should start if car is placed in neutral or not is this also call neutral safety switch
Customer: replied 1 year ago.
When I start the car I should have 12 volts on pin 85 and 86 correct
Expert:  Marty replied 1 year ago.

Yes it should start in park or in neutral. When turning the key to the start position you should have 12V across 85 and 86.

Related Mercedes Questions