2.3L ('83-'97) Random plugs and wires?

[91KateTheRanger]

Hey all! New to the forums. Got my first ranger. So I have some random wires that are wire nutted together, and then a couple that look like they should have some plugs. The one that is lower on the drivers side is a single wire and discovered that while doing the Sending unit in the block. The two red wires Idk what they are for, and the one by the relays, looks to be missing a plug.
I also have a intermittent Cel that takes the fuel pump some time to kick on or sometimes right away but have to wait for the cel to pop for the fuel pump to kick on. Has a new fuel pump, inertia switch, relay. Idk if any of this is related.

 

[rumblecloud]

Welcome to TRS KTR.
The boys are really good at wire chasing. Unfortunately I am not. When they all see your post, it will become a contest.

 

[91KateTheRanger]

Welcome to TRS KTR.
The boys are really good at wire chasing. Unfortunately I am not. When they all see your post, it will become a contest.

Haha, No worries! Thanks for the hope!

 

[RonD]

Welcome to TRS

The CEL should come on with Key on, always, that means the computer has powered up
The computer is what activates the fuel pump

In a 1991 there are 2 or 3 relays UNDER the engine fuse box
Brown base relay is the EEC/PCM relay, it is activated by ignition switch(key on), it powers computer(PCM) and fuel pump relay, not the pump itself

Green base relay is the fuel pump relay, it is powered by PCM relay but is not grounded so stays off, the PCM grounds it once it has powered up(CEL on), but only for 2 seconds to prime fuel system
PCM will ground it full time once RPMs are above 400(engine started), cranking speed is only 200rpms

Black base relay, WOT relay, and only found/used on Rangers with Factory Air Conditioning

From your description the PCM relay may have some corrosion on its wiring/contacts
Pull it out and have a look, if its not "closing" with Key on then no CEL/no computer

Or could be the ignition switch is not sending 12v to activate this relay reliably

Picture here: https://www.explorerforum.com/forums/attachments/relay-jpg.35945/

Drawing here: https://www.carfusebox.com/wp-content/uploads/2017/09/Ford-Ranger-1991-Passenger-Side-Fuse-Box-Diagram.gif


As for the extra or unconnected wires
Ranger wiring harness came with the wiring for all options available on that model, so pre-wired, if an option was not installed then the wires are "extra", not connected to anything
AC and cruise control were options on most Rangers and have wiring in engine bay, also automatic transmission wiring if yours is a manual trans

If you find things that are not working then you can post it here and we can look at what wire colors the non-working device used in 1991

 

[rumblecloud]

RonD always wins.

 

[91KateTheRanger]

Welcome to TRS

The CEL should come on with Key on, always, that means the computer has powered up
The computer is what activates the fuel pump

In a 1991 there are 2 or 3 relays UNDER the engine fuse box
Brown base relay is the EEC/PCM relay, it is activated by ignition switch(key on), it powers computer(PCM) and fuel pump relay, not the pump itself

Green base relay is the fuel pump relay, it is powered by PCM relay but is not grounded so stays off, the PCM grounds it once it has powered up(CEL on), but only for 2 seconds to prime fuel system
PCM will ground it full time once RPMs are above 400(engine started), cranking speed is only 200rpms

Black base relay, WOT relay, and only found/used on Rangers with Factory Air Conditioning

From your description the PCM relay may have some corrosion on its wiring/contacts
Pull it out and have a look, if its not "closing" with Key on then no CEL/no computer

Or could be the ignition switch is not sending 12v to activate this relay reliably

Picture here: https://www.explorerforum.com/forums/attachments/relay-jpg.35945/

Drawing here: https://www.carfusebox.com/wp-content/uploads/2017/09/Ford-Ranger-1991-Passenger-Side-Fuse-Box-Diagram.gif


As for the extra or unconnected wires
Ranger wiring harness came with the wiring for all options available on that model, so pre-wired, if an option was not installed then the wires are "extra", not connected to anything
AC and cruise control were options on most Rangers and have wiring in engine bay, also automatic transmission wiring if yours is a manual trans

If you find things that are not working then you can post it here and we can look at what wire colors the non-working device used in 1991

Will give that relay some hell tonight, I appreciate the detailed response! Will let ya know what I find!

 

[91KateTheRanger]

Welcome to TRS

The CEL should come on with Key on, always, that means the computer has powered up
The computer is what activates the fuel pump

In a 1991 there are 2 or 3 relays UNDER the engine fuse box
Brown base relay is the EEC/PCM relay, it is activated by ignition switch(key on), it powers computer(PCM) and fuel pump relay, not the pump itself

Green base relay is the fuel pump relay, it is powered by PCM relay but is not grounded so stays off, the PCM grounds it once it has powered up(CEL on), but only for 2 seconds to prime fuel system
PCM will ground it full time once RPMs are above 400(engine started), cranking speed is only 200rpms

Black base relay, WOT relay, and only found/used on Rangers with Factory Air Conditioning

From your description the PCM relay may have some corrosion on its wiring/contacts
Pull it out and have a look, if its not "closing" with Key on then no CEL/no computer

Or could be the ignition switch is not sending 12v to activate this relay reliably

Picture here: https://www.explorerforum.com/forums/attachments/relay-jpg.35945/

Drawing here: https://www.carfusebox.com/wp-content/uploads/2017/09/Ford-Ranger-1991-Passenger-Side-Fuse-Box-Diagram.gif


As for the extra or unconnected wires
Ranger wiring harness came with the wiring for all options available on that model, so pre-wired, if an option was not installed then the wires are "extra", not connected to anything
AC and cruise control were options on most Rangers and have wiring in engine bay, also automatic transmission wiring if yours is a manual trans

If you find things that are not working then you can post it here and we can look at what wire colors the non-working device used in 1991

Got a new relay, for my PCM (Oriellys part # RY610) and shaved the knob wing so it would fit, only relay with the correct switching and pole positions. She fires right up and no more intermittent CEL. I appreciate you much for that info!

 

[RonD]

Good work