ApexRK: It's the stock instrument cluster sensor. I know it's wrong because I have the 2-wire temp sensor hooked up to my MSEFI ECU and it reads correctly. The 1-wire cluster sensor reads way too high.
JDMClifford: Still stock engine. KA24E
johngriff: The Speedo requires a signal wire only. Neither one registers anything on the Speedo. The speedo also takes 12v and ground, but just to power the digi part of the gauge. Are those temp/voltage ratings for the 2-wire or the 1-wire sensor or both? The Fuel Level schematic in the FSM does show more than the other sensors, but I'm not sure if I'm reading it correctly.
azndoc: All the gauges are Autometer Phantom gauges.
I've mainly been working on getting the speedo working so I may not have tried everything I should on the other two. I'm thinking since you mentioned it's a magnetic sensor that maybe I should try grounding the second speedo wire. Does the sensor actually work like a mini generator? basically using magnetic influence on a coil of sorts to send a brief voltage spike? That would make sense...
I'll get my ohmmeter and check the 1-wire against the 2-wire and see if they're putting off about the same signal. That might at least get be starting on figuring out the water temp sensors.
Fuel level gauge is the one I'm a little clueless on. Here's the part of the Wiring diagram that shows the wires coming from the fuel pump. The other side that goes to the instrument panel doesn't tell us anything. Maybe the Red-Black is the only one I need? i'm just guessing.