Mercy! Mercy! That Dang Nabed PERCY!

More on Hooking up Gages

More on Hooking up the Gages

Today my paint came in to the parts store in Westfield along with the bucket that will hold my speedometer. I planed to mount that on the dash board and was eager to read the instructions. The instructions called for me to use the wires on the sending unit.

This created several problems. First I had no idea what the sending unit looked like or where it was located. Fortunately I had a Haynes Tech Book for the S-10 and it told me the sending unit was located on the transmission and a little bit about how it functioned. So, I raised the Stude on the lift and looked at the Transmission and sure enough there was a plug with two wires coming out. I called the tech line for the gage manufacturer and he told me he had no idea what they went to but suspected that one was the power and the other was the ground. That I should tie into them and run them up into the cab and hook them to the gage and see which one was which. Further he informed me that he suspected that the green wire was the power and the dark wire was the ground.

Now this was useful information but I just don’t want to cut and splice into the wires at the tranny connector because what if one goes to the computer and from there to the old Speedo.? Instead I decided to look at the plug that had connected the old instrument cluster of the S-10 and see if I could find a green one. Well there are several green ones and so tomorrow I will cut into them one by one and see what I can find out.

What I’ll be looking for is a green wire with switched power. If it is a ground wire it won’t have power and if it is continuously hot it can’t be that one either… So I have a color and a power condition to start with. Then I will assume that the harness grounded the original speedo and hook the green one to the new unit. Maybe I’ll get lucky.

It is amazing the complexity of the electrical circuits in modern auto’s and they get more so every year. If you look at the wiring diagram of an early auto you would be amazed at it’s simplicity. You had a coil, battery and a set of points and that was about it except for the lights.

That got me to wondering if you could have an auto without any electricity at all. I know what you’re thinking…The spark plugs need electricity to fire the fuel air mixture in the cylinders…but not if you had a diesel. Diesels don’t have spark plugs….However, you reply, but a diesel needs a fuel pump and a starter. Well, what if you parked it on a hill and put the fuel tank higher than the engine and let the fuel gravity feed. Hmmmm…theoretically possible but hardly practical. Anyway I was just thinking…

It is hot tonight and even though a breeze is blowing I am sweating. Think I’ll take a shower and have a cool drink of water