ms2 1st gen BP Wiring

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Hey guys, Great stuff in those stickys! I'm trying to get some wiring stuff figured out for my car. It's different, and it's my first swap, so please bear with me, any comments/suggestions are appreciated, at this point I'd even settle for some spam posts in my threads, nobody seems to want to help, or can't.


Anyway, the car is a 94 Aspire, the Engine is a 93 protege LX, the Engine harness is from a 91 LX, and the ECU is a stratified PnP 90-94 ms2.

I stripped all the old engine electronics and A/C component wires from my cars wiring harnesses. I'm looking at a mess right now, but I think it's gonna work. The Start/charge/main fuse box/dash fuse box/headlights... are all on my aspires wiring harness, and I'm trying to use the BP harness with the ECU, there's only a couple wires that need spliced to make this work, and I'm trying to figure out which ones those are.

First question, what is the deal with the fuel pump? I have to jumper power to it, ok, does it run constant (run/start) or does the ECU tell it when to kick on?

I have a thick blue wire from the BP harness, I think it's the main power to the engines electronics, and I've got a long tail from the old disty power (same thick blue wire) I'm about to splice together. I've figured out alot of the BP harness, but I'm hoping you guys can help me identify some wires. 30lbs of books and 6 fsm's and I'm still looking for a decent wiring diagram.. let me get some pics, sec.

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This is the two sockets I'm having trouble identifying, if you know what they're for please let me know!


This is the first socket I need to identify
this one is in the engine bay by the VAF/coil/ignitor/a ground
2 wires, brown/yellow and black


This is the other one
this is about 2' from the point where the harness comes out of the firewall into the fender well, I don't know if it goes out of the fender or not, my best guess is it's either the brake fluid level switch, or a transmission sensor switch

2 wires, white/red and white/green



there's also a couple straggler wires (5) by the ecu I need to identify yet.

[MD323]

thick blue is the coil man +12V

fuel pump either needs an additional mod to the MS to provide +12v to the circuit, or just cut the light green wire going to the fuel pump relay and wire it to the MS's fuel pump wire. both ways will provide a prime and shut off till the car starts.

this is your power and igntion relay switching wires. i believe its purple (+12v for F/P, white/red (main 12v), and black (ign relay)



the white/red and white/green is one of the solenoids. the wiring color depends on year of the harness

[b19gtr]

Im sure the black wire is ground.

White/red +12v

Purple starter signal for fuel pump

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alright, so purple wire on this harness is the fuel pump relay to trigger the relay, I need to look into my old aspire fuel pump wiring diagrams and figure out if that circuit still has juice, or if it's a circuit that i've broken. I'm not sure where it gets it's 12v from, maybe I could just use the existing fuel pump relay wire to the old ECU and delete that from this harness.

I've got a thick blue wire just like the blue one on the bp harness that went to the old disty from the starting system, I think I'll splice those.

are the white/red and black wires both for the ignition switch? That should already have juice from the existing wires.. I need to splice those into my existing ignition wire? I'll look into this further, I just woke up so I'm back at it again, thanks for the replies, at the very least it's a good place to start looking, feel free to tell me if I'm wrong!

[b19gtr]

[QUOTE are the white/red and black wires both for the ignition switch? That should already have juice from the existing wires.. I need to splice those into my existing ignition wire? I'll look into this further, I just woke up so I'm back at it again, thanks for the replies, at the very least it's a good place to start looking, feel free to tell me if I'm wrong![/QUOTE]

This connector plugs into the under side of the fusebox. To get the fuel pump working you can either jump fp and gnd in the fusebox or jump two wires on the vaf plug.

[b19gtr]

This connects to the underside of the fusebox in the engine bay.

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hey thanks bud! do you know if the diagram yun made is right? It looks SO simple compared to what I was trying to do, I'm a couple minutes away from stripping down the BP harness and stripping the VAF wiring altogether. I'm trying to figure out where this fuel pump relay is exactly on my car, it was getting juice from the main relay, which is now gone, so I need to jump power back to it at the relay after I figure out which wire to use. Then I'll run a wire from the relay itself to the ecu to close the circuit. I've got a good power wire that comes from the main fuse that I can use for it, just need to complete the circuit again.

[b19gtr]

hey thanks bud! do you know if the diagram yun made is right? It looks SO simple compared to what I was trying to do, I'm a couple minutes away from stripping down the BP harness and stripping the VAF wiring altogether. I'm trying to figure out where this fuel pump relay is exactly on my car, it was getting juice from the main relay, which is now gone, so I need to jump power back to it at the relay after I figure out which wire to use. Then I'll run a wire from the relay itself to the ecu to close the circuit. I've got a good power wire that comes from the main fuse that I can use for it, just need to complete the circuit again.

Basically there's two relays, one is the circuit opening relay, this is mounted on the ecu itself which controls the fuel pump, there's also the fuel resistor/relay which is mounted on the bulk head in the engine bay.

I have ditched both these relays, all you need to do is as follows,

you'll have a white plug next to the ecu connectors which supplies power for the coil etc.

All you need to do is solder join/solder two wires together

These are the green and green/red stripe wire. The green wire is +12v and green/red is ground to the fuel pump. I have these running to a switch.

You can then ditch all the rest of the wiring for the fuel pump relay and circuit opening relay.

Hope this helps.

Pop up a pic and i'll point out which wires if you want.

[b19gtr]

Yun's diagram is right, but it would be easier if you dont have the skills to build circuits to use the method i posted, for the fuel pump.

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I'm pretty sure I've got the FP under control to use my old relay and circuit so my fuel gauge still works in the cluster. I have the old power wire from the fuel inj fuse in the engine bay ready to splice into the w/gn for the new main relay, and the FP relay takes 2 power wires both come from the W/R wire off the main relay, then the BK/w goes to the pass compartment fuse box eng fuse (10A) this way the rest of the circuits going to the cluster are still intact with the old wiring. I'm just adding a power to the new main relay and pulling FP relay power from the main relay. I'll post a pic of the diagram if you want to look it over and let me know if I'm doing it right, sec.

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The power from the FI fuse in the engine bay is the only wire holding that main relay in place, the rest of wires were eliminated one by one when I separated wires from the old engine components from the bulk of the harness. It seems like the W/R wire on the new harness is just a general power wire for everything, so that's where I'll get power for the FP relay, and the rest.. I'll just ignore the purple wires in the BP harness since they're no longer needed.

what can you tell me about the blower switch input to the ECU, is it no longer needed at all? does it just bump idle speed if the blower is turned on? (i've deleted all the AC wires from my harness, but I need to defrost windows in the wintertime)

[b19gtr]

Looks like you have everything under control. Keep us updated.

[b19gtr]

The power from the FI fuse in the engine bay is the only wire holding that main relay in place, the rest of wires were eliminated one by one when I separated wires from the old engine components from the bulk of the harness. It seems like the W/R wire on the new harness is just a general power wire for everything, so that's where I'll get power for the FP relay, and the rest.. I'll just ignore the purple wires in the BP harness since they're no longer needed.

what can you tell me about the blower switch input to the ECU, is it no longer needed at all? does it just bump idle speed if the blower is turned on? (i've deleted all the AC wires from my harness, but I need to defrost windows in the wintertime)

The blower switch input is no longer needed, yes just bumps up idle, same with the defrost switch. You can bin these.