Classic 300d gauges

admin

I tried to replace broken gauges on my machine with aftermarkets. I got the temperature wired up and decided to go to lincoln gauges stopped. My machine would not even turn over. I then took off the aftermarket gauge and connected the wires together that were suppose to be connected and taped them off. Then it would turn over but my glow plugs would not click the hours meter and I could not get it to start. Do all the wires to all the gauges have to be connected for it to crank and run?  Thanks.
Reply:I guess the 300d is like my 200d as far as the gauge wiring goes.The power comes from the starter to the outside post on the ampmeter.  The starter button is also connected to this post.  The other side of the ampmeter is the two wires from the alternator, the master switch wire, and the glow plug wire.The temp guage has one wire coming from the sending unit on the inside and a power wire coming from the master switch on the outside post.  Center post goes to chassis ground.The oil gauge is either connected to the master through the temp or the temp is connected through the oil gauge.  I can't remember right now.  The other side goes to the sending unit. Center is ground.Since the rev-up controller board monitors oil pressure and water temperature then I might be safe to say yes, they need to be wired up for the engine to start (and keep running).  It also powers the hour meter, so by it not working now then I might say it's probably not getting power.  Its power comes form the master switch.If you have your original doors then on the inside of the left hand door is a wiring schematic that I'm sure will help you.  Its also in your owners manual if you have that.I could walk out in the garage and look but that's how I think it's wired anyway. lolGood luck manLater
Reply:Thanks so much. I had to leave it in my shop and come back up here to Alaska working for three weeks. Been wondering if I may have burnt a relay or something !!  Whew..
Reply:I think the way it works is you feed power to one side and the other side goes to ground through the sending unit.  The different values on the gauge are different amounts of ground depending on the pressure/temp, etc.  The gauge must be of the same ohms value as the sending unit for its reading to be correct.The ammeter is simple.  You put the power on one side and the load on the other.  As the current crosses the gauge it shows a discharge.  If you also put the charge wire on that other side then when the alternator puts out current it travels backwards through the ampmeter (to the battery via your power wire) and shows a charge.If you ever noticed the starter motor doesn't show up on the ammeter is because it draws too much current to be connected directly through the ammeter.  To show its amount of discharge on the system a shunt must be used.Good luck