Wiring Diagram or wire colour help please?? | Ford Explorer Forums - Serious Explorations

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Wiring Diagram or wire colour help please??

blueka

Elite Pickler
Elite Explorer
Joined
December 18, 2005
Messages
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Location
Liverpool
City, State
UK
Year, Model & Trim Level
97 UK XLT, 99 Sport V8,
I'm nearly finished with the V8 swap, now, I've searched the forum for wiring diagrams and come up short...

I have checked all my ground/earth points and they all seem fine..

What I now have is no oil pressure on the gauge, which is causing the red "check gage" light on the dashboard..

It won't pass a safety with that light on...

so.. I need to find out, what wires on the engine harness are for the signal from the oil pressure switch on the following

2000 5.0 V8 engine wiring
2000 4.0 SOHC V6 Engine bay wiring

my intention is to bridge the wires across the big black plug in the engine bay as I'm sure this is where the wiring problem is

Thanks

Si
 



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Dark Green/White wire

For SOHC V6:
oil pressure switch > dark green wire > C125 pin 8 > C147 pin 18 > instrument cluster

For OHV V6 & V8:
oil pressure switch > dark green wire > C115 pin 26 > C147 pin 18 > instrument cluster

C147 is located by the battery junction box

C115 & C125 are the main engine harness connectors

I doubt low oil pressure will result in a Check Engine light because I can't find a connection to the PCM.
 






on the 2000 EB SOHC, we have a sticky oil switch. Until the gauge reads pressure, then the red "check gage" light comes on, but as soon as pressure reads, the light goes out. I'm guessing it will do the same with this. I've just got to get the gauge to read something.

Si
 






do you think running a bridge wire from the sender to pin 18 on the plug by the battery would be a good idea? I checked the earth on the back of the engine yesterday and it made no difference.. .


Si
 






Ok, so which plug do I look for the dark green wire in? I re-checked the voltage this morning across the switch and there was nothing, so I'm going to run a bridge wire to the switch and see if that makes a difference.
I have 3 plugs in the engine bay, which one would be best?

200720111624-1.jpg

200720111625-1.jpg

200720111626-1.jpg



Si
 






which connector?

It looks like the connector in the first photo above the upper intake manifold is C115. If so, it is a rectangular 42 pin connector. There are six rows of pins. The top and bottom rows have 9 pins and the middle four rows have six pins. Looking at the male connector with the pins pointing toward you Pin 1 is at the bottom left and pin 42 is at the top right. The dark green/white wire should go from the oil pressure switch to the female connector.

From the C115 male connector there should be a dark green/white wire going to the C147 male connector pin 18. C147 is almost square with the slightly longer sides tapered near the corners. It is a 40 pin connector with two rectangles of pins. There is a tab on one side of the male connector. With the tab at the top the bottom left pin is #1 and the pin numbers increase from left to right. Pin 18 is on the right side of the inner rectangle. The dark green/white wire goes from the female connector to the instrument panel. I believe C147 is one of the connectors at the firewall below the battery junction box. It is not one of the connectors in the three photos you posted.
 






ok, so, I had a look at the plug above the manifold and removed some of the tape so I could access the wires... the female plug has a green/white wire going into a hole. the hole next to this one is marked 27 on the plastic, so I assume that this green/white wire is 26.
it's the top left wire in the picture
200720111627.jpg


However, there is no green/white wire on the other side of the plug (male side)... I am totally colourblind, so I got Sarah to have a look and she can't find a green/white wire either

Si
 






C125 connector

I think I understand the problem. Your wiring for the oil pressure switch is for the SOHC V6 which uses C125 instead of C115. C125 is a ten pin square connector with two columns of small pins and two columns of large pins. It is directly aft of the batter and I believe it is the connector shown in the second photo you posted because three of the large pins are not used. Seven of the small pins are used so it might be easier to use the V8 wiring harness that connects to the oil pressure switch. It will take me a while to identify all of the signals going to/from C125.
 






C125 used pins

After flipping quickly thru the wiring pages I found that C125 pin 9 (yellow/light blue wire) goes between the starter motor relay and the starter motor and C125 pin 12 (white/pink wire) goes from the engine low oil switch to the message center. Your check engine is probably from low oil level instead of low oil pressure.
 






After flipping quickly thru the wiring pages I found that C125 pin 9 (yellow/light blue wire) goes between the starter motor relay and the starter motor and C125 pin 12 (white/pink wire) goes from the engine low oil switch to the message center. Your check engine is probably from low oil level instead of low oil pressure.

He is not getting a "check engine" light. He is getting a " check gauge" light because the cluster is seeing no oil pressure.

We need to step back and verify oil pressure exists Simon. If the oil pump is bad --or not getting drive from the cam sensor the gauge will not rise.
soooo


You need to check if the sender "switches state" when the engine is started.

Now, I do not know if this is a normally open or normally closed sender-but either way-you measure ohms of the sender itself , with the connector disconnected from the sender.

when running and when off, they should be different.
 






Link to wiring diagram for 2000 5.0

wiring diagrams...
2000 5.0 V8 engine wiring
2000 4.0 SOHC V6 Engine bay wiring

I have a bunch of the wiring diagrams. Which 4L ones do you need? The EI or the SOHC? They also have it separated into "Early Production" and "Late Production" but it doesn't give build dates. I can send both.

I'll edit this in a second when I find a place to upload a zip file with the 2000 Explorer 5.0 Engine Wiring Diagrams.

OK, here's the link to the wiring diagrams for the 2000-Explorer-5-0 EngineWiringDiagram

Sorry it makes you wait a few seconds to download. If anyone has a suggestion for a file sharing site that works better, let me know.
 






oil level is fine, did an oil change shortly after firing her up for the first time.

I retested the plug and there is no current across it in either state. So, would I need to complete the sending circuit first in order to test it?

I really hate wiring...

Si
 






I would also just like to say thanks guys for the help so far...

I wound back the stopper on the throttle body too, I'm now idling at just over 1000 rpm.. still too high, but I'm unsure as to how to get it back down some more...

I'm guessing that once I've got voltage in the oil pressure switch circuit then I will probably have a working gauge.. or at least one I can test.


Si
 






Hmm, I'm trying to come up with a way to explain this.

Set your meter to read ohms.

when you touch the leads together the meter should go to 0--indicating 0 ohms or a closed circuit.

when they are seperated a digital meter will usually show a 1 to the far left indicating open.

When the engine is off-the sensor (being a switch) will be open.
When the engine is running, the sender will "close" the circuit to ground if oil pressure is present.

Simon, how many actual wires go to the oil sender on this engine? what I mean is, how many individual wires in the plug?
 












OK I just happen to have a 2000 5.0 at my disposal.

Here is the oil sender--it is kinda hard to get to

004-3.jpg


You need to set your meter to the ohms scale. second from lowest is ok

Disconnect the oil sender. Place the red lead here

005-4.jpg


make sure it is making contact with the metal pin.

clamp the black lead to ground. Any ground will do.

your meter should now read like this

006-2.jpg


indicating way high off scale. Infinite ohms=open circuit.

now have someone start the truck. You shouldn't be in the way of moving things but double check --
when the engine is running, the meter should look like this

007-2.jpg


or, at least be a readable digit within the meter scale.

If this is a new sender and it doesn't do this, we need to back up.
 






ok, well, Thanks Jon, I'll take a stab at that tomorrow, I'm not allowed to work with the shop door open after 11pm... people complain cos I've got no mufflers. :)

Si
 






When troubleshooting electronics, you always test the input ( sender) and output (gauge) of a circuit first, then look for trouble in the middle--(wiring)

We need to verify oil pressure is good.

teall ya what--do this.

this is a quiet test. disconnect the lead from the sender. Stick a wire in the harness and touch the other end of wire to the negative battery terminal. Now go turn on the key--see if the gauge moves. Do this very fast, just long enough to see the gauge move.


This will verify the circuit works from sender to gauge and will not make a sound.
 






ok, give me a few mins, and I'll come back and let you know... funny guy!


Si
 



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ok, so I put a wire on the end of the sender and ran it to earth... no change in the gauge... did you want me to try it the other way? wire in the plug and to ground?


Si
 






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