Originally Posted by a1320addict

I apologize, I was referencing off a DC2 chassis, misread your original post..thought it was in an ITR.

Either way, can you post a picture of the melted fuse? If I'm understanding your correctly, that would be your Radiator Fan. If it is MELTED, as opposed to blown, remove it and see where you get. It's not really great to have a melted fusible link still in place, lol.

Originally Posted by fcm

Your misunderstanding how the PGM-FI Main Relay works and what it does.

The PGM-FI Main Relay, as you say, has two(2) relays in it, one is the fuel injector relay the other is the fuel pump relay, when you turn your ign. switch to the run position, this will happen, [or should happen] the ign switch will supply the PGM-FI Main Relay power, [12.5V or whatever batt. voltage is] that power goes to the fuel injector relays coil, [other side of coil is grounded] it also supplies power to the input, #30 of the fuel pump relay, this lead is almost always a yellow/black.

When that power is supplied to the PGM-FI main Relay there will be two(2) "clicks" from the PGM-FI Main Relay, first click is the fuel injector relay turning on and the second click is the fuel pump relay turning on, these "clicks" are very close together so they can sound/feel like one click.

At the same time, [when you turn on the ign. switch] the cluster will light up, including the CEL, the fuel pump will start priming.

After no more then a few sec. there will be a third click from the PGM-FI Main Relay, fuel pump relay turning off, at the same time the CEL will go out.

If any of the above is not happening the engine will not start, and the problem is related to the PGM-FI Main Relay, it may not be the relay itself, but related to it.

The fuel injector relay, [when on] supplies power to the fuel injectors, [obviously] internally to the fuel pump relays coil, to a few engine valve/solenoids and heated O2 sensor if you have one, last but not least and very important to IGP1 and IGP2 at ECU/ECM, both IGP1 and 2 must have batt. voltage on them or not much of anything will happen, ECU/ECM will not supply the ground for the fuel pump relays coil, ECU/ECM will not pulse the injectors, just to name two things.

The first things you should test for is...

1- Injector relays coil ground, [black] is a good groung, [full continuity to chassis ground]

2- the PGM-FI Main Relay has all three(3) of it's powers, unplug the relay and test for batt. voltage

There must be a 12V constant lead, [hot at all times] normally yellow/white, whatever the color there is only one 12V constant and it must be batt. voltage, it is the input, #30 to the injector relay.

There must be a 12V switched lead, [hot in run AND start] normally yellow/black, again fuel injector relays coil and input, [#30] to the fuel pump relay.

There must be a second 12V switched lead, [hot only when cranking to start] normally blue/white

The colors of the lead may differ from model to model/year to year but not what they are and when they are hot.

You need to confirm 12V+, [batt. voltage] at IGP1 and IGP2 when ign. switch is in run AND start.

If any of the above is not right engine will not start.

Check what I have suggested and let me know what you find. 94

Originally Posted by turbohatch96y7

okay i attached a really big pic of the schematic for a 93 si p28
the yellow lines are your 12 volt input for your ecu.. if you are getting 3 volts at the relay than most likely you have a bad connection at the fuse box or the fuse has developed internal resistance..

breakdow of whats happening in the pic...
batter volts comes in at fuse 31 in the under hood fuse box supplies voltage to the relay tips when the key is turned to the on position..

Originally Posted by g230sport

Have you replaced that fuse yet? And any chance the ignition switch is bad?