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I have an 80 4WD, and parked it in the garage yesterday. Ran fine. Went out this a.m. and it started just fine, but as soon as I let go of the key, it acted like the ignition had just been shut down. It'll start fine, just won't stay running. Thought it might be an ignition switch, and changed it out with another that I knew to be good, and still have the same problem. Where do I start looking, and what do I look for? Is it a relay?

First, as obvious as it sounds, check your fuses. A blown voltage regulator fuse could cause about the same symptoms you described.

Check for +12 VDC on the secondary side of the coil with the key on. If you have it, then something is open in the rest of the circuit. If you don't, work your way backwards, starting with the ballast resistor.

Check the fuel pump relay, although this doesn't sound like a fuel issue to me. There are several threads on how to do this on the site.

There are two relays under a tin panel on the passenger fender well. One is the fuel pump relay and the other is a latch relay for the ignition system. It will be the one closest to the firewall when the cover is mounted. You can look at the wiring diagrams here on the site to see how it's wired.

Check the pedal switches. Sometimes one will stick, or work it's way out a bit and not close when it should. My guess is that your problem is the switch on the clutch pedal/arm (probably has black w/white stripe wires). You can jumper them directly together to check the circuit.

Good luck Let us know what you find....

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