rickcj7

I just bought a 97 that won't start, no spark fuel cel or codes.
After some checking the fuel pump will run if I jump the relay and I have no 12 volt to the ASD pin 86.
Is pin 86 powered by the pcm or the ignition switch???

ET JEEP

Pin 86 should be powered by the ignition switch. Both the ASD and the Fuel Pump relays are on the same power circuit. Turn you key to on and check for 12 volts at pin 86 on both relays.

The PCM controls pin 85 on each. The PCM provides a path to ground for the relays to work.

This is what the book shows but they could be wired in reverse as the control circuit is not polarity sensitive. Power to pin 86 is the most common way to wire the relay.

When you first turn the key to start, both relays should work for a few seconds. Then the PCM turns them off until you crank the engine and the PCM gets the signal from the cam sensor and the crank position sensor. When it reads the signal it then turns the relays on for engine start.

rickcj7

I don't have power at pin 86, so sounds like an ignition switch?

I can't read codes and the check engine light doesn't come on either, that must be tied in also.

ET JEEP

It looks like the fuse, switch or the wiring.

First check the fuse. Do this, just to make sure. Have a helper turn and hold the switch to start. Then check pins 86 and 85 on the ASD and Fuel relays. One of those pins, more likely 86, should have battery voltage. According to the diagram it should be 86 with power.

If you don't read voltage then the problem is the fuse, the ignition switch or the wiring.

Check the fuse in the distribution panel. Use a meter don't just look at it. Some of these fuses have small pins on top. You can check for voltage by touching each pin with the meter positive lead and the black lead to ground. You should have voltage on both pins.

If the fuse does not have the pins, remove and check with an ohm meter. It should have continuity.

ET JEEP

I just looked at the circuit for the CEL. It, too, is on that circuit. It may be a fuse problem.

I don't know if the fuses are marked but the book show fuse F12.

rickcj7

It was the fuse a 20 amp in #11

Fuse #11 transmission control module, powertrain control module, automatic shutdown relay, fuel pump relay