2000 5.0 V8 picture help required

[blueka]

So, I've nearly finished my V8 swap...The wiring loom to the ECU is slightly damaged..

Could someone with a V8 take a picture of the wiring harness by the ECU showing me if there's any wires going to earth/ground points on the firewall?

I've got 2 wires that are broken and I don't know where they go

Thanks

Si

 

[2000StreetRod]

ground wires

According to my 2000 wiring diagrams the 5.0L has the same ground connection from the PCM wiring harness to the firewall just like the SOHC V6 shown below.

The two wires that connect to the terminal lug under the stud bolt at the firewall are black. One goes to PCM pin 25 (chassis ground). The other goes to a splice that connects to the shield of the crankshaft position sensor, the GEM and the DTR sensor.

 

[blueka]

Thanks... I wonder if that's going to help with my no oil pressure on the gauge issue?


Si

 

[2000StreetRod]

no oil pressure on gauge

Thanks... I wonder if that's going to help with my no oil pressure on the gauge issue?
Si

I doubt it. If the tachometer or the voltmeter works then there is power and ground to the oil pressure gauge. You may have a bad oil pressure switch or a bad connection to it. The oil pressure switch is closed for normal oil pressure. If you short the dark green/white wire to ground with the ignition switch in Run you should have a normal indication on the gauge. If so, then you have a bad switch. If not, then you have an open connection between the pressure switch and the instrument cluster. You can check the DG/Wht wire at the 42 pin C115 (main engine harness connector) or the 40 pin C147 (near battery junction box) in the engine compartment.

 

[vroomzoomboom]

if you need a pic of something simon, let me know. just text me, that way i can go and get them for you.

 

[Turdle]

The oil sender is on the driver side of the timing cover. Check that the wire is plugged on good. Some have a push on type while 99? later have a plastic connector. You need to know which one you have before getting a replacement.

 

[blueka]

so I ran a wire from the sender plug to the earth on the battery... and nothing changed on the gauge.. .bad sender?


Si

 

[Turdle]

no
you eliminated the sender without testing it-

hold up-check all the fuses again, seems like there are several which go to the instrument cluster.

What you did was ground the gauge. Switch the key to on and check voltage from the sender wire to ground please.

 

[blueka]

I'm no good with electrics.. how do I check that? I'll check it all tomorrow..


Si

 

[Turdle]

put the red probe inside the push connector that goes to the sender (sender is disconnected), black probe on negative battery post and read volts with the key just switched on

 

[blueka]

ok, so what setting do I need the tester on? (yes, I know I'm a retard)

what should it read if it's working properly?


Si

 

[2000StreetRod]

not the pressure switch

so I ran a wire from the sender plug to the earth on the battery... and nothing changed on the gauge.. .bad sender?
Si

If you connected the wire from the oil pressure switch connector pin for the dark green/white wire to the battery negative terminal and the ignition switch was in Run and there was no reading on the gauge then your problem is not the pressure switch.

If the battery voltage indicator works when the ignition switch is in Run then there is voltage and ground to the oil pressure gauge. They are connected together in the instrument cluster. If the battery voltage indicator does not work then check fuse 11 (7.5 amps) in the central junction box.

If you measure the voltage between the oil pressure connector DG/Wht wire/pin and ground when the ignition switch is in Run the voltage should be somewhat less than battery voltage. If not, the problem is in the path of the DG/wht wire as I explained in my earlier post.

 

[blueka]

ok, well, the battery voltage indicator is working, so I'll check the wire and the voltage across it this morning, and then go from there... I think I'll order a new switch anyway if it's only cheap


Si

 

[blueka]

ok, so.....

I put the red prong from the tester in the switch plug and ran the black to the earth on the battery.

I put the tester to DCV 20 and turned the igntion all the way without starting the vehicle.

the reading I got was 0.00 to 0.01

so I'm guessing that I've got insufficient power going across the switch?

I ordered a new switch from Napa anyway.. only $18, will be in thursday

So no what??


Si

 

[blueka]

changed the switch for a known good one... still no action on the needle... rechecked the voltage across the switch it was coming up at 0.24 ish, instead of of the 0.01 that it displayed earlier.. could it be the earth strap on the back of the engine? or is it something else?


Si

 

[vroomzoomboom]

simon, maybe try swapping gauges for another set that you have (if you have). if you dont, let me know. i have a few kicking around here, just pay postage.

 

[blueka]

story so far...

replaced switch, replaced gauge.... no difference...

going away for a few days, will have another stab at it when I get back

Big thanks to Turdle for the phone advice!


Si