Doing away with my Engine Computer

[Bob Hatcher]

I am doing a 1979 4 barrel Holley carb/302 swap into my 2000 2wd Ranger and have some questions - I removed my original multi pin engine harness plug & entire wire harness from the firewall - since I am retaining all of the original gauges in my dashboard, I thought of plugging it back in only using the wiring to the original 3.0 water temp & oil pressure sending units so the factory gauges will still work - am I correct in thinking that will work and, if so, what other wiring would I need to retain? Would anything removed possibly hinder my stock ignition switch/ ability to start the truck type problems for instance? Also in my mind is my electric fuel pump operation going to continue if I keep the stock tank and use a pressure regulator to reduce the efi pressure to 7 psi - Thanks

 

[franklin2]

Yes, in your year you can use the original gauges. Warning, your original oil pressure gauge is fake. Ford started doing this in the mid 80's. Your original oil pressure sending unit is just a switch. It is open above 5 psi oil pressure, Ford put a resistor in the cluster to make the oil pressure gauge read in the middle at all times. Only when your oil pressure drops below 5 psi, the switch closes and it makes the oil pressure gauge then drop to zero. Some people go to the trouble to modify this circuit to make it really read the actual pressure.

Your fake oil pressure sending/switch wire is a darkgreen/white.

Your temp gauge is real, the sending unit wire is red/white

The voltmeter picks up power off the cluster power.

Your fuel gauge is a yellow/white wire.

Here's a diagram of the cluster.

 

[Bob Hatcher]

Yes, in your year you can use the original gauges. Warning, your original oil pressure gauge is fake. Ford started doing this in the mid 80's. Your original oil pressure sending unit is just a switch. It is open above 5 psi oil pressure, Ford put a resistor in the cluster to make the oil pressure gauge read in the middle at all times. Only when your oil pressure drops below 5 psi, the switch closes and it makes the oil pressure gauge then drop to zero. Some people go to the trouble to modify this circuit to make it really read the actual pressure.

Your fake oil pressure sending/switch wire is a darkgreen/white.

Your temp gauge is real, the sending unit wire is red/white

The voltmeter picks up power off the cluster power.

Your fuel gauge is a yellow/white wire.

Here's a diagram of the cluster.

Thank you - invaluable information - saving for later

 

[Brain75]

in the tech library there is the how to article on swapping the fake oil sender for a real (variable resistance) one and bypassing the resistor on the back of the cluster.