brokeanduuggllyy7

I have an 01/86 mazda gxl I had a fire that burned my wiring harness so I bought an 04/87 gxl I spliced the harness from the 87 to replace the harness that was burned in my 86 and all wires match but 7 why would they be diff? besides being a S4 and S5 ? how can I tell what I have ? thank for any help you can give me.

aka_rocket

it seems you used two s4 harnesses. 86 and 87 are s4.

idsigloo

Ya, series 5 starts in 89.

HAILERS

If it was a late 87 it's possible it does not have the solenoid resistor and wiring to it that your 86 did . You did not specify which harness you burnt up. Got me. You've a Emissions harness, a front harness and a engine harness. I'll forget about the rear harness.

therotaryrocket

in the faq for fc at the top of the 2nd gen specific page you can look up factory service manual wiring diagrams. it would probably be easier to swap the entire engine harness un-cut including the matching ecu. were the numbers on the ecu the same? i have an 88 gxl and the computer from an old 87 gxl parts car, i think they were N326 and N327 respectively, then my turbo II is N333? idk, but i hope this helps.

brokeanduuggllyy7

my whole harness into the engine burned so I am replacing all wires from the fire wall up but like I said 7 wires dont match up.

HAILERS

What colors? White/red? Brown/Red ? Black/White? Green/White? Yellow/White????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????

brokeanduuggllyy7

ok from the harness on the 86 I have 2 brown wires with black lines down them on the 87 I have 2 green wires with black down themand orangse cross lines I also have a mystery wire that has no where to go.

swiftfc

and what color is that mysterious wire?

HAILERS

All Brown/Black wires are grounds from sensors that go back to the ECU on pin 2C.

There is ONE Green/Black wire on the Emissions harness. It's for pin 2F on the ECU and is for the VARIABLE RESISTOR.

There is another GREEN/BLACK for the electrical fan water temp switch. It does not go to the ECU but to the Front harness from the Emissions harness.

The mysterious wire with no color is for the Fubar Network and works with the Engine Fail Box.

brokeanduuggllyy7

black with orange dot

HAILERS

There are only two wires on the EMISSIONS HARNESS that are BLACK on a 86-87 car. One goes to 3G and the other to 3A. Both are the GROUNDS FOR THE ECU. One end of each wire is on top of the rear rotor housing in a ring termianl. The other ends go to either 3A or 3G. Both are the ECU ground wires. Down near the ECU the 3A splices with 2R and if you have a turbo, the 3G splices with a ground to the Knock Box.

All this is childs play. All you need is the wiring diagrams from the fsm which is free and online. The FSM shows the ECU and the color of wires going to the two plugs on the ECU that come from the EMISSIONS HARNESS thay you are splicing together.

Note: the car won't start and run if the ECU grounds are missing. They are 3A, 3G and 2R.