Hooking up speedo to SR20 swap?

[1320VR4]

Okay, there's like 70,000 threads related to this out there but I really can't find any actual information that will help me hook up my speedometer.

I have a 94 240sx, automatic body harnass. I swapped in an SR20DET red top.

How do I go about hooking up the speedometer. Which wires need to be spliced where and what additional parts might I need to successfully convert for the new trans. If anyone can explain or has a link to a walk through, that would be excellent.

thanks,
Matt

[e1_griego]

You need to use your auto lower harness.

Put a multimeter on your batt and see how many volts the batt is getting -- guessing in the 15+ range (if you used the SR 5spd lower harness).

Swap the auto one back on and everything will work fine.

[j20accord00]

i could have sworn I use the vehicle speed sensor from the sr with a sr lower harness and it worked fine.

[e1_griego]

Yes, it works fine in a 5spd car.

But auto chassis is wired differently and requires auto lower harness. No mixing and matching allowed.

[racepar1]

The speedo plugs right in, no wiring necessary. The only thing that needs to be wired up is the reverse lights.

[1320VR4]

You need to use your auto lower harness.

Put a multimeter on your batt and see how many volts the batt is getting -- guessing in the 15+ range (if you used the SR 5spd lower harness).

Swap the auto one back on and everything will work fine.

Yeah I'm getting around 15 volts and I couldn't figure out why, it did the same with two alternators. I don't have my original lower harness since I bought the car half hacked.

Does anyone have a cheap lower harness so I can just swap it and have everything working?

[e1_griego]

Yup, exactly.

Auto lower will fix all your problems. The alternator wiring and speedo wiring is different on auto cars, thus your problems.

[Black240Ct]

use a KA speed sensor, an SR speed sensor wont read in MPH,

i know a manual KA speed sensor will work, not sure if an auto is the same.

and your KA lower harness should plug right into it. if not its just two wires. you can find an FSM and splice it into those two wires if you dont have the chassis plug for the speed sensor.. but you should

[e1_griego]

Bzzzt. Wrong.

s13 vss are the same.

[1320VR4]

or alternatively is there a method to using the 5spd harness?

[e1_griego]

http://zilvia.net/f/s-chassis/324332-s13-5-speed-swap-question.html

[racepar1]

or alternatively is there a method to using the 5spd harness?

No, you need to use the KA auto lower harness. You can eliminate most of the harness. You just need the alternator/starter wiring, the speed sensor wiring, and the reverse light wires. The M/T harness WILL NOT plug into your chasis harness.

[1320VR4]

http://zilvia.net/f/s-chassis/324332-s13-5-speed-swap-question.html

My car was 5 speed swapped before I bought it, I scrapped the stock wiring because it was so freaking botched. It's half the reason I went with an SR swap because I really needed to swap the full harness and all vacuum lines from scratch.


Does anyone have a lower harness I can buy? Or is there a method to directly splice wires.

Also I'm having the issue where the car is running 15 volts, why does this occur? (yes I know wrong harness but what is plugged in where that makes the voltage higher?)

[S14DB]

S13 SR20DET to S13 240sx Transmission Wiring Harness | Wiring Specialties (http://www.wiringspecialties.com/wsprs13srins3.html)

[1320VR4]

^well would ya look at that. lol