Author Topic: Burnt starter motor wiring  (Read 5009 times)

jerrycastillo

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Burnt starter motor wiring
« on: June 29, 2015, 11:17:34 »
Hello,

The wires to the stater motor from the oil pan junction connector run just under the HOT exhaust mani and its insulation sleeve is charred. The wires' insulation (cloth) still holds! What was the original wire protection in the car to avoid charred wires? Has enyone encountered and solved this problem? How? Thank you!!

Gerardo

1970 280SL Horizon Blue

66andBlue

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Re: Burnt starter motor wiring
« Reply #1 on: June 29, 2015, 17:14:14 »
Gerardo,
perhaps your cable is not routed correctly through the cable holders around the oil pan?
See photos in reply #9 here: http://www.sl113.org/forums/index.php?topic=13803.0
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

jerrycastillo

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Re: Burnt starter motor wiring
« Reply #2 on: June 29, 2015, 19:29:56 »
Thank you Alfred! I have seen the brackets with the rubber grommets loose along the battery wire and wondered where they would hold. Now I know! :)

Still, the wires from the oil pan to the starter motor run very close to the exhaust manifold and take a lot of heat. Was that the original way they were laid out?

Gerardo
1970 280SL Horizon Blue

66andBlue

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Re: Burnt starter motor wiring
« Reply #3 on: June 29, 2015, 23:14:52 »
It is difficult to see but from your photo it appears that the cable is routed above the engine support arms. It should be below.
« Last Edit: June 29, 2015, 23:19:19 by 66andBlue »
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

jerrycastillo

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Re: Burnt starter motor wiring
« Reply #4 on: June 30, 2015, 03:03:57 »
Alfred,

Thank you for your additional comment!
Looking at the photos you referred me to it is clear mine is INCORRECTLY routed ABOVE the motor mount. That brings it too close to the exhaust manifold. I will reroute the cable BELOW the motor mount.
Do you have to remove the starter motor from the flywheel case to have access to the cables attached to it or are you able to work without removing it? Thanks again.

Gerardo
1970 280SL Horizon Blue

ja17

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Re: Burnt starter motor wiring
« Reply #5 on: June 30, 2015, 05:22:05 »
Here is a picture of the battery cable/starter wiring bracket locations.  You can disconnect it from underneath without removing the starter. The protective sheathing is nothing special. The cable is far enough from the exhaust manifold if routed correctly. I use a fiberglas/rubber sheathing which protective, but is most likely overkill.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

jerrycastillo

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Re: Burnt starter motor wiring
« Reply #6 on: June 30, 2015, 10:47:27 »
Hi Joe,

Thank you for the photo and explanation! They are very useful to do the job right.

Gerardo

1970 280SL Horizon Blue