Wiring Help..

the situation..

1991 Ford Mustang
ECU AND Wiring to ECU removed
Carbed 302 (306) in the process of being installed
AOD REPLACED with C4
ALL gauges being replaced with Autometer Guages
Need help laying out the wiring... the gauges in green I have under control.. the ones in red I need a hand with.. I listed the ones I "know" just in case I screwed something up.. lol also was wondering if I could simply tie into the factory harness behind the cluster OR if those wires went south with the ECU and ECU harness removal?

is there a factory sensor I can remove? no ECU so don't need any of the factory stuff? where should I locate this?

Oil Pressure - ?

Water Temp - ?

Tachometer - ?

Fuel Level - ?


Fuel Pressure - mechanical mounted on cowl ran to port on fuel line near carb
Trans Temp - sensor inline to cooler
Speedometer - remove speed sensor from AOD and install in C4
Vac - T in vacuum line
Nitrous Pressure - to solonoid
Pyrometer - wired to sensor in exhaust

thanks in advance!

so for fuel level.. I can use the yellow wire in the back of the cluster? my fuel level gauge is the one calibrated for the 5.0 fuel level sender...

the wires in the back of the cluster will still be "live" even with the ECU removal?

double post

jrichker said:

I will refrain from my usual unpleasant remarks about converting an EFI car to carb and point you to AutoZone's self help section. Enter your vehicle , year and model and then click on repair guides. If you navigate all the way to the end, you will find a a wiring diagram for what's left of your original wiring.

Click to expand...

I appreciate your help.. and your ability to stick to the topic...


but since you asked (kind of)

my motor was acting up... and causing all kinds of drivability issues.. and leaking a whole lot of oil in more than one place... radiator was shot.. just tons of little problems..

to be fair and honest.. I am a novice at best.. the motor and trans were a complete package at an extremely low price because the person who started the project could not afford to finish it... so for me it was appealing..

also to note was that when I was removing the ECU and all associated wires.. there were several that were VERY rough.. some of the wiring in my power windows had already gone south..

I understand that being carbed will make the car FAR less driveable.. I also understand that 5.0 + fuel injected = win... but to be honest.. not interested.. I am not interested in making 1,000 hp.. I am not concerned about the drivability advantages of fuel injected..

what interested me was the ability to ditch a **** ton of wiring.. sensors... and an ECU.. SIMPLE.. maybe not the best.. but it is plenty simple...

so there you have it.. maybe in your eyes I made a stupid decision, and well since I have no idea WTF I am doing.. you are likely right.. but at the end of the day for what the car will be (a weekend toy) I think I will be more than satisfied (providing of course I can even finish this thing.. LOL)..

vladtepes said:

so for fuel level.. I can use the yellow wire in the back of the cluster? my fuel level gauge is the one calibrated for the 5.0 fuel level sender...

the wires in the back of the cluster will still be "live" even with the ECU removal?

Click to expand...

I meant fuel level.. NOT pressure..


and just to be clear... without the ECU and associated harness.. the wiring in the back of the cluster WILL or WILL NOT still function?

I understand that there are other places I can tap into sensors but for things like fuel level it would be very convenient to just tap the wire that is right there.. I suppose for the tach I can do the same..

providing these wires still function sans ECU and harness..

thanks to all of you for the help.. it is greatly appreciated..

will likely just pull right from the cluster harness as it is right there..

any help on wiring diagram for gauge cluster for 91 fox body... looked through some of those links.. found a lot of great info.. but no full cluster pinout?

thanks in advance..