location of fuel pump relay on my 93 astro (w)

[crash]

thanks the the reassurance doc..

I got out there this morning and that lasted about 30min.. then the sky opened up and we're getting thunder storms. there are a few weird things I've found so far. about 4 - 5 wires that have been taped up since it left the factory. also a single wire doesn't go through with the rest of the harness. it seems to pass through the firewall into the ecm harness by itself. looks orange in the engine bay, joined to a red then i loose it in the harness.

until i can get back out there again, is there a way to unplug that large plug and pass the large harness from the footwell into the engine bay? it looks like it'd be way easier giving me an extra foot or more to inspect

thanks again guys
rob

[lockdoc]

As far as getting that junction block apart, JUST LET IT GO! lol. It's a weatherproof connection that is not meant to come apart. There should not be any wires going to ecm through the firewell outside of that connection. That stray wire is a good place to start. Although there are a few orange wires in the harness, one of them goes between the fuel pump relay and the PCM. Keep in mind there are many taped up factory splices in the harness. Most will contain black, red, pink or orange wires as they are the majority of the power and ground wires.

[crash]

ok.. between thunder storms.. here's what I've done.

btw.. it seems at some point there was a remote starter/alarm in this thing. the brain is removed (wasn't there when we got it) and there has never been issue in the 4 or so years we've had it.

on with the mess... the stray orange to red to orange wire I cut out the crap piece and soldered in a new good piece. had no effect.
there were a few wires that ran between the oil dipstick and the valve cover. the loom was a little crusty, I stripped away the loom and the wires appeared okay so i ran some new loom over them. looked to me like they headed down to the vicinity of the starter.

i took some pics of the oddly spliced wires, not sure what they are for but a couple i stripped away the tape at the splice and they looked ok

pics are below

no matter how i wiggle anything now i can't get the fuel pump to kick on. thing is there doesn't appear to be any wires that have broken loose or anything. i've tugged on all of them ](*,)

first pic shows that stray orange wire going threw the block on it's own. seems to have been a repair at some point.

[lockdoc]

The blue ones are the knock sensors. One blue spliced into two. A remote starter would have been wired into the harness around the PCM. Chances are that something from that is causing the problem. Question. Are you able to get the fuel pump running if you use the test lead? Let me know. Another thing I thought when reading over everything. You mentioned it ran poorly when you first started the engine last time then it improved. That happens sometimes when power is disconnected from the ECM. It has to learn again. Did you pull the fuse for any length of time? If not, a power wire to the ECM could be bad. A couple wires to check that are fuel pump related at the ECM are E16 (orange) and F6 (dark green\white) in the blue connector and B12 (gray) in the red connector.

[crash]

Question. Are you able to get the fuel pump running if you use the test lead?

which is the test lead. is that the loose gray one just dangling by the relay?

You mentioned it ran poorly when you first started the engine last time then it improved. That happens sometimes when power is disconnected from the ECM. It has to learn again. Did you pull the fuse for any length of time? If not, a power wire to the ECM could be bad.

at that point my description was inaccurate. it seemed like it was bad initially, then better. in hindsight, i think it was the bad connection getting better, perhaps.
which are the main power wires for the ecm?

A couple wires to check that are fuel pump related at the ECM are E16 (orange) and F6 (dark green\white) in the blue connector and B12 (gray) in the red connector.

the orange in the blue connector is the one that i repaired. the gray looks suspicious to me. after i do check all of these, how do i actually test them? what should and shouldn't have power and when? lol

[lockdoc]

You need to get the wiring diagrams for your van so you can trace them and see what they do. You check the wires by doing a continuity test with a multimeter. Place one probe on the end of the wire on the plug at the PCM and the other probe where the wire terminates at the other end. For example, place a probe at the orange wire at the PCM and the other probe at the connector at the fuel pump relay with the orange wire. There should be little to no resistance. Most meters have one of those beeping functions. If it is good, it beeps. If not, it doesn't. The three wires I gave you go to the fuel pump relay. And yes, the loose gray wire by the relay is the test port. Apply 12 volts to that wire and the pump should turn on.

[crash]

well my meter isn't that fancy, i can test continuity but don't have a beep setting LOL

anyhooo... I applied 12v to the gray fuel pump test lead and YES the pump turns on fine.

I'll get on with testing the rest .. I think i need wayyyyyyyyyyyy longer test leads though :-k

and I do have the wiring diagrams.. shhhh!

[lockdoc]

Bastard! lol

[crash]

SUCCESS!!!

i decided to check that stray wire again .. just because it was suspect right out of the gate. had continuity from the pcm to my newly made connection and about 4 " past that I had nada...

it was split inside the sheathing. i was pulling and bending and such and found a soft spot.

cut out the bad piece, soldered in the new wire and viola!!!!!!!!!!!!!! pump kicked in.. fired right up

the orange wire is... looks like battery feed to the pcm, and/or power to the fuel pump relay

you have a pm doc

[lockdoc]

=D>