I had to swap this sensor when I did the head swap. The '91 350SDL that this head came from had 4 cntacts, IIRC. After reading through the 1986 Supplement, it seems to me that the green coolant sensor in question should be normally open. The official test is:
Start engine, pull 1-pole connector from coolante temperature switch 105/120C and connect to ground. The A/C compressor must be switched off immediately. If required, eliminate line interruption or replace Klima. Can someone pull the connectors off their green coolant sensor and check if they are normally open? This is the sensor that sits next to the fuel filter where the coolant comes into the head from the top radiator hose. TIA all, Luther On Thu, 19 Jun 2008 20:44:57 -0500, Peter Frederick <[EMAIL PROTECTED]> wrote: > It's toast, I think. On the 300D, one wire is the fan switch, should > be open, but the other two (two wire plug, if the plug is still > intact) is a thermistor. May be a switch and a thermistor on the > W126, I'm not sure. Could be a coolant temp switch, too for that > matter, you will have to check, I don't have the W126 manuals. I'd > replace it -- make sure you know the engine and chassis number, as > they changed during production and aren't interchangeable. > > Peter > > On Jun 18, 2008, at 11:09 PM, Luther wrote: > >> That sensor plug is keyed and cannot be reversed? I've applied >> some Deoxit to all of the coolant sensor connectors. I've checked >> the resistances of all of the coolant sensors, and the 3 pronged >> green (see the picture link) showed open to ground, and open across >> all 3 combinations of prongs. Sounds like it isn't good? >> >> picture is here: http://www.gulseth.net/photos/coolant-sensor.jpg >> Luther >> > -- Luther KB5QHU Alma, Ark '87 300SDL (272,xxx mi) head case '85 Ford F250 6.9 diesel (x58,xxx mi) '82 300CD (166 kmi) '82 300D (74 kmi) getting donor engine-sold '85 300D (280,176) parts car sans engine _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
