1959 Other Cadillac Models V8 Two Wheel Drive Automatic
I have a 1951 Cadillac 62 Series Sedan. I selected 1959 above because your drop down menu does not go any older.
I have completely replaced the wiring harness with an EZ-Wire harness, due to a meltdown from the alternator sliding and grounding out, which took out the fuse block. I have a set of after market electrical gauges made by Dolphin. Here's the problem. Before the " Meltdown" the gauges worked fine (Fuel, Water Temp, Oil Pressure and Amp meter). The Tach and Spedo work as advertised. I have read out all of the wires going to and from the gauges. I have good power, good grounds and no shorts between the two that I can find. The wires from each sender reads good as well, no shorts to be found.
When the car is first started, the Oil Pressure Gauge pegs out, the fuel pressure gauge appears to operats, the water temp gauge does not move (not warmed up yet) and the Amp Meter does not move. Once the car is warmed up, Oil Pressure stays pegged, the Water temp Pegs, Fuel Gauge Pegs and the Amp Meter still does not move.
Troubleshooting steps so far. Disconnected the oil pressure and the water temp sender, both one at a time and individually. When any one of the sender's are disconnected, none of the gauges move from Zero. This is baffling me. I could use any assistance that you can provide.
Most guages work off of a low voltage thing like 7 volts or so. If yours is peggin out it sounds like they are either grounding out or when you had the " meltdown" you did more damage then you thought. Try putting a resistor between the voltage source and the guages and see if this makes a difference. If it does then you have to much voltage going to the guages. Also it is better to have a volt meter instead of an ampmeter as the wiring has to be parellel for it to work. IN other words the poswer has to go through the amp guage instead of just to it. Volt meters due the same just different and easier for the novice to hook up.