ok, but what does it connect to? people on another group think it may be for the alternator but I'm not so sure? I have a 10si alternator on the engine this harness will go on and this plug does look very similar to it though. but I'm not sure?
I'm going to spend some time looking through some diagrams tonight and hopefully figure it out.
plug pic.jpg
ok I think it may have been to some sort of fuel module that I dont need? I cant really tell what else it could have gone to. though I will say there is no black/white on the plug. but where my finger is pointing on the printout is the only thing it could be?
there is pink/black at terminal C and tan/white at terminal A...I dont know.
20240312_193617.jpg
It appears the connector pictured is for an ATC fuse, see link below. Pink wire with a Black stripe is typically ignition "ON". Not sure what the tan/white wire is for.Originally Posted by stackz
https://www.amazon.com/Fastronix-Sol...01LWNVT61?th=1
interesting. I wonder if its the 20a in the pic then. most likely I think. gonna probe some stuff later this morning and check it out.
ok, I'm pretty sure its the fuel pump test connector. not sure if it just stays unplugged like this when not in use or not. The tan/white wire traces all the way back to pin B2 on the ecu connectors.
The pink/black stripe wire go over to the oil pressure sender plug. then from the other side of the oil pressure sender plug its the orange wire to the fuel pump relay.
I assume I need to jump this wire or the oil pressure sender wont be doing anything?
The fuel pump relay wiring described above seems odd to me.
Typically, the fuel pump wiring high side gets battery+ from a wire with an inline fusible link or a fuse that eventually is connected to the Battery + terminal.
The computer supplies a battery + signal to the fuel pump relay low side, with the other low side terminal connected to ground. When the fuel pump relay high side contacts close Battery + is sent to the fuel pump.
Typically, the oil pressure switch wiring gets battery+ from a wire with an inline fusible link or a fuse that eventually is connected to the Battery + terminal.
Typically 5 PSI of oil pressure closes the oil pressure switch to send Battery + to the fuel pump.
Typically the oil pressure switch fuel pump wire and fuel pump relay fuel pump wire are spliced together so either the fuel pump relay and / or oil pressure switch will supply Battery + to the fuel pump.
Typically ECM Terminal B2 is spliced into the wire that sends Battery + to the fuel pump.
Possibly the wiring diagram shown below is helpful.
Fuel Pump Relay.JPG
I have that wiring diagram sitting next to me at my desk actually and have the notes from binder planet snipped in under it.
it seems weird to me as well but if it works I'm cool with it. I tried taking some overall pics of it. I put a 20a fuse in the connector we think is the ATC. you can see how it just sorta splices into the main harness in the first pic. In the second pic you can see how the oil pressure switch loops back to the pink/black splice and to the orange power wire to the relay. with the way it loops from the tan/white from the ecu and there is nothing left aside from it on the other side of that splice, it kind of has to stay in place as a fused signal I guess? the piece of the tan/white that you see that is cut went to something else not part of the main engine harness (when I grabbed this harness I just grabbed literally everything under the hood as one big mass). but thats why I think this is the fuel pump test connector maybe?
20240314_143328.jpg20240314_143334.jpg
Last edited by stackz; 03-14-2024 at 09:55 PM.
The fuel pump relay actually has 3 high side connectors, that allow for Normally Closed contacts and Normally Open contacts.
The fuel pump power is connected by the Normally Opened contacts.
The fuel pump prime is connected by the Normally Closed contacts.
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