VSS speed sensor wiring problem

[rswails]

Hi guys I have a 1992 S13 ( originally auto transmission ) with a RB20DET swap with manual transmission. I am having trouble getting my speedometer to work. I know my speed sensor works, it is generating voltage ( ~1.5VAC ) in 2nd gear idle throttle. I have tried hooking the VSS wires to the yello w/ green strip and yellow w/ black stripe wires on the fat bundle of wires right beside the battery. This doesn't work. I have read the voltage at the pin 53 of the ECU and this doesn't get any voltage, so the problem is somewhere before that.

Now, I have heard from a post here that you hook the speed sensor wires to 2 white w/red striped wires in the bundle of wires by the battery. I have only found one such white w/red stripe wires there. Can someone please tell me exactly which 2 wires to hook my VSS wires to with my exact setup? I'm thinking maybe since my S13 was auto transmission that mine is different?

Thanks a lot guys.

[rswails]

bump

[240z4u]

Sounds like a VSS speed sensor wiring problem to me.

Get out your schematics and start chasing the signal, I am guessing it is going missing at the plug under the dash. Not totally sure, I have an S14 and reused my stock a/t lower harness with no issues at all.

[rswails]

Finally I got the right wires now. It turns out that the speed sensor wires go to the following wires by the battery fuse box.One hooks to the yellow w/ blue stripe, other hooks to the yellow w/black stripe.

[TwoJayZee240]

I know my speed sensor works, it is generating voltage ( ~1.5VAC ) in 2nd gear idle throttle.

shouldnt you be reading it in VDC?

[rswails]

Nope. The VSS is a simple generator. Generators naturally generate AC current. A rectifier must be installed to convert to DC current your alternator has this.