So I got my daughter to turn the key while I put the voltmeter on the
solenoid wire (purple). Nothing going to it. Hmmmm.
There is 12V to the starter. That cable comes off the back of the
alternator from a cable that goes from the battery to the alternator and
they appear to be bolted together there on the back, so that is a direct
12V connection.
I moved some relays around again for the solenoid in the fuse box, I
could feel and hear the relay click but still no power to the starter
solenoid. hmmmm.
I opened up the fuse box to see if I could see the largish purple wire
coming out of it at the bottom of the fuse/relay panel and going to the
solenoid but there was no purple wire. I followed it from the starter
solenoid and it appears to go up over the engine in a harness that runs
along the injector rail and goes somewhere, I thought into the fuse
box. But since I don't see it in there, I am now wondering if this switch
https://www.fcpeuro.com/products/mercedes-ignition-starter-switch-ml320-ml350-ml430-ml500-ml55-amg-1685451004oe
might be bad. "The ignition starter switch is used to activate the
main electrical system for your vehicle. A starter switch provides power
to the starter solenoid, electronic control unit (ECU) and ignition coil."
I guess that could be it as I am not sure if there is anything else in
the circuit that could be bad since the relay is clicking, and I
measured 12V across the relay socket. I guess I could try a direct
jumper across that to see if any power is going to the solenoid, or to
see if the relay is getting power to trip it when the key is turned.
Have not done that yet. I don't know if that relay sends power to the
ignition starter switch, but now I'm thinking it must as I did not see
the purple wire coming out of the fuse box so maybe it is coming off the
switch?
Tomorrow I will try to put power directly to the solenoid and see if
that energizes it and I can get this thing started.
AAAAARRRRRGGGGGHHHHH!!!!!
--FT
On 4/29/20 4:02 PM, Meade Dillon via Mercedes wrote:
I like that idea. Start your T/S at the starter end. After verifying that
the starter motor will engage, try to power the solenoid.
-------------
Max
Charleston SC
On Wed, Apr 29, 2020 at 3:42 PM Curt Raymond via Mercedes <
mercedes@okiebenz.com> wrote:
Big screwdriver across the starter to prove that it works? It'd be
annoying to troubleshoot all around it only to find that the starter is
bad...
-Curt
On Wednesday, April 29, 2020, 3:31:43 PM EDT, Floyd Thursby via
Mercedes <mercedes@okiebenz.com> wrote:
I have been fooling around with this ML500 that I don't have a title for
as it has a lean.
Recall that when I first got it it was showing a Start Error and there
were various codes for this and that, which I cleared but it would still
show a Start Error but no new codes showed up so that did not indicate
much of anything. Thinking it might be the DAS ring I picked up another
one off an ML at LKQ last Saturday and swapped that in to see what might
happen. It was a different part number but same unit it looked, plugged
in fine. No joy, still a Start Error. So I put the old one back in and
gave it a go, no Start Error now (YAY!!!) now but still no cranking
either. Everything else lights up and whirs and clicks and makes the
right noises except the starter.
I've scanned it several times and no codes at all, everything looks good
in the various nannies so that is good. So at least the Start Error is
gone. There is a red light on the dash that blinks once or twice that
supposedly indicates the alarm has not disabled the car, and I could get
it to blink and stay solid using the fancy computer to trigger it then
go back to "normal" so that suggests it is not disabled. I saw no other
switches and events that would indicate that.
There were some suggestions I saw that indicated a coupla relays might
not be working so I checked those, swapped in other ones, I could hear
them clicking, power at various pins on the relay sockets were good and
the nannies said they checked out. Since I am seeing voltages at the
relays I have to conclude the ignition switch is OK as it lights up the
dash and the relays and such. I've also put good batteries in, voltages
are good, but nothing is cranking.
Turns out there is a 100A ceramic fuse on the positive battery terminal
that looks like the starter connects too, the fuse was good near as I
could tell, looked clean and fairly new. But maybe not, I was thinking
to clamp the cable directly to the terminal to see if that worked but
didn't yet.
So now I am thinking there must be a bad starter relay somewhere, if
there is one, that I am not seeing. Maybe on the starter? Only thing I
have seen is the small relay in the fuse box under the hood, which
appears to be working. Or the starter solenoid itself or the starter
has gone bad? I have not been under the car yet to see if there is
voltage going to the starter or to try to put power directly to it. I
don't even know where it is! I guess I will have to look at that aspect
and see what else I can determine.
Any other ideas or suggestions?
--
--FT
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_______________________________________
http://www.okiebenz.com
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To Unsubscribe or change delivery options go to:
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_______________________________________
http://www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
--
--FT
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