Help PLEASE--1976 300d

[Hey-Hof]

I have a '76 300d and am having issues with gauges not working, fan not working, and A/C not working. I have a piece-o-crap Haynes manual and well, it's good for, well nothing except to say I have a manual. I also have a CD manual that doesnt seem to cover my 115 model. Can anyone point me in the right direction of preferably a good paper manual. And if you can point me in the direction of a good wiring diagram during my search for a manual, that would be appreciated. I was told my car is a grey market vehicle whatever that mean.


Thanks

[79Mercy]

Its not gray market car, in europe they called them 240D 3.0's, not 300D's.

Check the fuses, thats prolly why the gauges do not work.

Which fan doesnt work? heater or AC?

[t walgamuth]

If you have more than one electrical guage acting up you should check your ground on the instrument cluster. They are notorious for acting up when the ground is shot.

The speedo and oil pressure guages are mechanical so unaffected by ground.

[Hey-Hof]

Neither of the fans work.

All fuses seem to be good. There are 2 sets of (extra) 2 fuses one set being located near the battery and the other on the right side of engine near the fire wall. What are these extra fuses for as they are not labeled?

Where is the ground on the instrument cluster? The rheostat has been replaced with a straight piece of insulated wire already. Sometimes the gauges wont move at all. Others times they will peg all the way up.

So, will a repair manual from a 240d work? I dont claim to be a mechanic but have always done my own work on all cars I have owned. So, I do have mechanical abilities but this is my first Benz and without the help of this forum and no repair manual I'm stuck.

If it wasnt so dang hot where I live I would just stick to the good old reliable classic Beetle in the garage.

Thanks for the help

[pop & blow]

Start at the fuse box, then pull your guage panel out and check the plug for power coming in the back plugs in,it does sound like a ground problem they all gound together to the dash you should be able to see grounds anfter panel is removed, disconect your oul line fist fefor removing panel will give you more room. one thing just because the fuse looks good doesn't mean it is good.

[alabbasi]

Interesting thread, I have a similar issue in my 73 280CE (w114). A/C and blower do not work, instrument lights, blinker and head lights do not work either. Day time running lights do.

All fuses are fine.

[kraakevik]

The fuse-box connections for the A/C and power windows often corrode--you may have to unscrew the Phillips-head screws mounting the wires to the boxes and thoroughly wire-brush everything down to bare metal to get a good connection.

I've been known to rewire all that firewall stuff into two or three heavy-duty glass fuse in-line holders good for 35 amps apiece--which has proved to be a permanent fix.


Tim Kraakevik
kraakevik@voyager.net
Four M110's

[jettskiman]

I had this problem when driving the other day. Everything worked great the day before. I noticed that none of the instrument cluster/ blinkers and other stuff not working. I wiggle the key in the ignition just a little and everything came back up. I think its getting old and I had turned it just a little bit to far past run or on and it wasnt making contact for all of the other stuff. 1976 300d

[tram]

Originally Posted by jettskiman

I had this problem when driving the other day. Everything worked great the day before. I noticed that none of the instrument cluster/ blinkers and other stuff not working. I wiggle the key in the ignition just a little and everything came back up. I think its getting old and I had turned it just a little bit to far past run or on and it wasnt making contact for all of the other stuff. 1976 300d

Bingo. Most multiple electrical failures that come out of the blue on items that are switched on with the ignition wind up being due to a worn ignition switch. Seen it many, many times on both gasoline and diesel models.

[1975300D]

Which gauges don't work? The fuses on the firewall are for the starter relay. I wish I knew what the fuses by the battery are for because I have one circuit that has no continuity in it and my AC and blower motor don't work either.