F15HY

Alright my Third Gens I need your help. I'm going to take out the EFI and put in the Carb Setup. My thing is what do i need to do with the wiring harness what do I cut out and not cut at all. Or if somebody can give me a wire diagram and something about the wiring harness. I already looked into the forums for the conversions for the carb setup but they don't explain about the wiring harness like how do you know what to keep or just cut it.

So please I would like some of your input thank you for time and help.

bestracing

There are two harnesses on your car in the engine bay. The ECM harness and the motor/chassis harness.



Here is the ECM harness for your 87



The Pink wire and White wire coming from the distributor will be in the engine harness and will hook up to your new distributor.

For the fuel pump,
at the relay cut the dark green/white wire leaving about 2" out of the connector.
Run a switched +12 volts to the relay and solder it to the dark green/white wire.
On the tan/white wire cut and remove only the portion going to the ECM and MAF relay
On the Orange wire, cut and remove only the portion going to the ECM, burn off relay and MAF relay.

Dual Fan
With a dual fan set-up you will need to rig a system to control the second fan because it was controlled by the ECM. The dark green/white wire from the ECM to the Fan relay will have to be cut and spliced into the temperature switch in the passenger side head.

five7kid

iTrader: (14)

"Location: Los Angeles, CA"

This is not a good move.

F15HY

thank you so much for your help and taking your time to explain the way it needed to.

F15HY

hey i know its a bad move but I know a few friends that let me pay under the table

oH HorizoN

I am also looking to do this swap in the future. Thanks for that diagram, saved!

t-top havoc

iTrader: (3)

IIRC--
You can remove the harness that does to the ECU, but if you have a VSS, retain that, & fan control if it controls the fan(s).
Ours was done by a PO. Sorry I can't be of more direct help.

There may be a way to get around VSS, fan(s) may be changed to a fan control of your choosing.

( edit )
Torque converter control is another thing to consider. ECU or aftermarket.

bestracing

My 86 T/A has the VSS system. What I had to do was trace the yellow and purple wires from the transmission to the ECM bulk head connector in the passenger side kick panel. Cut the wires off from each side of the bulk head connector and solder them back together. (note, I left about 2" of wire on either side of the connector in case I wanted to put the ECM back in) Now the VSS buffer board is grounded through the ECM harness ground so I had to splice in a new ground wire to get it to work.

After I did this my check engine light would stay on but since it isn't used anymore and I didn't want to track down the circuit to turn it off, I just removed the bulb and put the socket back in.

bestracing

Just an FYI...

That diagram is year and engine specific, 1987 TPI. You can find other diagrams for other years and engine options here---> http://www.austinthirdgen.org/index.php?pid=19

F15HY

Is there anything else I need to be aware of when I rework the wiring harness?

bestracing

Double check to see you have the right wire and follow it through the harness before cutting.

Use a piece of sheet metal and RTV to cover the hole in the kick panel where you removed the ECM harness. I used RTV for two reasons. Seals out the water and fumes and it can be removed if need be.

BOD1979

iTrader: (1)

What do I do with the dark green that went to the AC from the ECM and there was a tan/white that went to the alternator

bestracing

The Tan/Wht wire that goes to the Alt should be connected to the fuel pump relay as pictured in the schematic.

According to my 89 service manual the dark green wire lets the ECM know when the A/C is turned on. I believe it doesn't need to be hooked up now since you removed the ECM.

2012sergen11

iTrader: (1)

Hey guys, I know this is a little off topic from the engine bay wiring but I am looking to do this swap and wanted to post to a more recent thread. On my 87 do I need to do anything with the speedometer drive when I disconnect the computer or is it gear driven? Thanks in advance

TTOP350

iTrader: (8)

I don't want to sound like a buzz kill but I wouldn't cut out a thing until your sure you want that carb on there long term.

2012sergen11

iTrader: (1)

If you leave the computer and wiring harness intact after putting the carb on will anything need to be cut or is that just if you are removing the harness to clean up the engine bay?

F15HY

Hey five7kid i need help for setting up my fuel system thanks

F15HY

Or can anybody help with the fuel system setup like which afpr should i get and where to mount it at and i'm still going to use the in tank fuel pump for it so it would be very helpful if somebody can help me. and so should i get a temp control fan switch for the dual fan setup for my oe fans? thanks

five7kid

iTrader: (14)

Mallory 4309 or another brand that does the same thing. Mount it in the engine compartment close to where the fuel line ends now.

F15HY

Thank you very much is there anything else I need to worry about?