1981 300SD wont start after being driven for an hour or so - PeachParts Mercedes-Benz Forum

teej · #1 03-10-2006, 10:50 AM

I seen a post on this earlier that suggested a starter change. Im curious if that cured the problem and if so what technically was happening to it. Im also wondering if the glow plugs are tied in with the starting circuit in a way that it could possibly shut down the starting system. The car will start after an hour or so of being shut down, there is no inbetween it either starts good or nothing at all, not even a click. Im hoping that someone has been down this road before and can help me out. Thanks in advance. If anyone knows a place to find schematics on the internet, preferably for free Id love to know where to get them thanks.

larry perkins · #2 03-10-2006, 11:15 AM

tee i have one doing that now, bought a wagon from mexico, havent had time to trouble shoot, fellow before me placed a jumper wire from b+ to the starter solenoid valve. when it wont start, cycle the key to glow position, walk around to the jumper, connect to b+(battery) and the starter should cycle.
i think my problem is a connection under the dash(forgot the terminal number)
larry perkins lou ky
87 old cars

teej · #3 03-14-2006, 12:25 PM

Thanks, I havent had any time to troubleshoot myself, and I dont have any electrical prints to refer to. Im wondering now, what sensors/warning lights....are being by-passed when jumping directly to the starter solenoid? If anybody has or knows where I can find an ignition schematic for an 81 300SD I would greatly appreciate it. Thanks

t walgamuth · #4 03-14-2006, 05:27 PM

wouldnt hurt to check your cables and grounds.

the heat sink can sink your current flow. hot wires (and very cold) have a lot more resistance so it can start up fine then when good and hot not start. this can happen with grounds being the problem or any number of other electrical things. but cables and grounds are simple and easy.

tom w