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I'm trying to wire a few gauges in my truck (1971 F250 390V8), but I'm not sure which wire to use for the 'switched' power / acc position / on position from the ignition is. I'm using the below wiring diagram from the other site.
My question is: would I connect the neutral wires to the red, green or blue highlighted wires to connect my power to the gauges from the ignition switch, or another wire? I understand the ground goes to a good bare metal surface somewhere on the truck. Also, to connect the lights on the gauges, would I connect them to the RED-YEL wire comming off the light switch and horn connector? The gauges I'm looking at wiring are the volt meter (neutral and ground), tachometer (neutral to the 12v source, grnd, neg on coil, and light wire), and the lights for the gauge pod (neutral and grnd).
I would find the radio wire, that will give you "keyed" power and easy to tap into without cutting into ignition wiring. Plus it will be fused already. Pull instrument cluster and find the bullet connector that powers the radio. Easier to work on without having to stick your head under the dash.
I would find the radio wire, that will give you "keyed" power and easy to tap into without cutting into ignition wiring. Plus it will be fused already. Pull instrument cluster and find the bullet connector that powers the radio. Easier to work on without having to stick your head under the dash.
The hard part about this is the previous owner pulled the stereo out of the truck. I'm currently running with no stereo. The wiring diagram above doesn't show any stereo, so I'll go and see if there's any wire to/from the stereo area in the dash. Hopefully I can find one.
I did see this. My truck has the gauges and not the idiot lights. It also appears stock as the wires don't appear to be cut in any way going to the connector for the printed circuit board.
It will be a single bullet style plug, should be close to where the radio was. Have a tester handy, and probe any loose single plug and check to see if it gets power with key ON.
I scanned through a few wiring diagrams and didn't find any color code for the radio circuit. Just have to look for the loose plug.
It will look like this, but black in color: It will be the female side.
I'm trying to wire a few gauges in my truck (1971 F250 390V8), but I'm not sure which wire to use for the 'switched' power / acc position / on position from the ignition is. I'm using the below wiring diagram from the other site.
My question is: would I connect the neutral wires to the red, green or blue highlighted wires to connect my power to the gauges from the ignition switch, or another wire? I understand the ground goes to a good bare metal surface somewhere on the truck. Also, to connect the lights on the gauges, would I connect them to the RED-YEL wire comming off the light switch and horn connector? The gauges I'm looking at wiring are the volt meter (neutral and ground), tachometer (neutral to the 12v source, grnd, neg on coil, and light wire), and the lights for the gauge pod (neutral and grnd).
Thanks for your help.
Gump1376
A few things come to mind...
The concept of a "Neutral" wire doesn't apply - that's for alternating current, not direct current. To run gauges, you generally need a signal source on one side of the gauge and a ground on the other side (one exception comes immediately to mind, which is the ammeter gauge). Sometimes, you will find that the signalling component is on the same side of the gauge as the ground (such as with the coolant temperature circuit).
I don't think "stereo" radios were available as original equipment, although there were plenty of aftermarket stereos available.
I agree on finding the Aux. Power Connector that the OEM radio plugged into. You might be able to trace the Black/Green (1970 colors) wire from the Windshield Wiper Switch back to the three-position female bullet connector. For 1970, that connector connected back to a junction that was fed by wire #297A (Black/Green) from the fuse block.
The 1972 wiring diagram that you are using is for Instrument Clusters with idiot lights. The Master Wiring Diagram for 1972 shows both idiot lights and gauges. There are differences at the Voltage Regulator, Alternator and Instrument Cluster (and possibly elsewhere). Keep those differences in mind when you are trying to modify your electrical circuits. To make things work correctly, you may need to make more wiring changes than are initially apparent.
You may find it easier to use the 1970 diagrams (F100-250 for idiot lights, F350 for gauges).
The following may help, even through it's written for a 1970:
The circuit you are seeking would be active during Step 2) ("ACCY ONLY"), which is also active during Steps 3) and 4). I wouldn't tap into the resistance wire - that's for engine ignition and operation. Use wire #297 (or one of the wires connected to it, such as #297A or #297B,)
Instead of using the wires that you've marked in Red, Green and Blue, try using the wire that feeds power to the Windshield Wiper & Washer Switch. It should be active when the key is in the "ACCY" position.
