S4 ignition switch with S5 car/Harness
 

Simple question, can i use the s4 ignition switch on an s5 car with the s5 ignition harness? It fits and turns on the auxiliary and it does pull voltage to the starter but it doesnt crank it

When you say it pulls voltage to the starter are you referring to the spade connector which activates the starter.

mistyped i meant i get an eletrical click but no crank the clock on the idiot light turns off showing its pulling voltage my car is also a manual swap so there might be other issues but im trying to go one by one

You have to bypass the inhibitor switch if the car was formally an auto.

really? Ok how would i go by doing that?

Is this car an NA or turbo?

na s5

The wire coming off of the starter cut relay (speaking of the thick Black/Green wire) runs to the inhibitor switch which is usually bolted to the transmission (auto). The wire runs through the switch and connects to the Black/Red wire which runs to the spade connector of the starter solenoid. You need to bridge these two wires so as to allow the voltage from the ignition switch to run to the starter cut relay and then onward to the starter solenoid. The inhibitor prevents autos from being started in gear thus your switch is preventing the flow of current from the ignition to the starter.

The S5 standard transmission has an interlock switch which prevents the car from being started in gear (cousin of the inhibitor). Are you planning on using the interlock?

crap this sounds difficult, my plan was to not use the interlock but which ever way is the simplest and i have an s5 trans how to do block the interlock switch on the tranny?

You jumper the two wires as noted. (Speaking of the inhibitor here)

this is the wiring ive done so far

https://cimg0.ibsrv.net/gimg/www.rx7...9e0006b92d.jpg

Not sure what B/Y wire is at the top of the diagram or the a b c plug towards the bottom left either. Did you trash a lot of your wiring or are you using the stock wiring.

stock wiring but some were already trashed from the laziness of the last owner who rather cut the wires than unclip it

Are you familiar w/the starter cut relay? If so, are its wires intact?

im not to familiar unfortunately im currently waiting for the rain to pass here in boston so i can get under the car again and search for it

It's bolted to the fender near the trailing coil and right next to the main relay (it has only one plug w/4 wires).

W/key to start the Black/Blue wire at the ignition switch is powered. This wire runs to the starter cut relay. Make sure this is occurring on your car.

If the above were to check out then the thicker of the two Black/Green wires at the starter relay would also have voltage w/key to start.

The B/G wire runs to the inhibitor. The inhibitor also has a Black/Red wire.

If these two wires are fused to each other than the B/R wire, which runs to the starter solenoid, then the B/R wire would have voltage w/key to start.

ok got it now where would the black/green wire and the black/red wire be? im guessing on a plug

A two wire pug that was previously connected to the inhibitor switch.

so i have just to follow the trail from the starter cut relay to the two wire plug and bridge the two? apologies for all the questions i just want to make sure i do this correctly

this great thank you so much for the help!

The thick B/G from the starter relay runs to it but so does the B/R wire from the starter solenoid.

ahaha so i wired it and my reverse likes come on when i crank it i found the thick B/G but i might have wired it to the wrong B/R

Reverse lights has a B/Y wire and a R/G wire. It's B/R to B/G (inhibitor) and not R/G to B/G (there's a difference here). The plug w/the B/R and B/G wires also could have the R/G wire and R/G is for reverse lights (not the start circuit).

ok im sure i got the inhibitor wiring correct(ill check with a multimeter tm), but its still not cranking. but now when i crank it all the idiot lights go out and there what sounds like a grinding noise.

maybe i installed the starter incorrectly but ground to trans, negative to starter terminal and the spade, leaving the terminal with copper fitting empty

The idiot lights are supposed to go out because they run off the ignition 2 fuse which loses power w/key to start so the voltage can be used for the items necessary to start the car. If you bridged the voltage at the starter which comes from the battery to the spade for the starter solenoid it should engage the starter. The long mounting bolt is for the negative/ground on the starter and the other large bolt is for the battery positive.