Oddjob

Old problem from '05. I ended up using a factory rear wiper toggle switch installed in its normal location on the center console. Switch cuts the power to the relay. On the 944 system, there is power to both the hydraulic unit and the control unit. Only one needs to be cut to shut the system off, but both need to be cut in order to reset the control unit fault warning (relay does this).

The other problem I had when I was doing this, I had one bad wheel sensor and my ABS relay was also intermittently failing. So I had all sorts of fault and reset problems that made it more difficult ensure I had everything wired and installed properly.

I used all factory parts from a couple used/parted cars, including the ABS wiring harness. My car was an 87, so it had the connection in the main wiring harness to attach the ABS harness. Otherwise it would have been a lot of work to wire the relay into the fuse box.

924RACR

twisted pair.

Lemming

What gauge?

APKhaos

On my 89 Turbo S the ground line is switched. The ABS system harness is completely separate from the main harness. There's a brown ground lead and a red +12v lead that run to the ABS relay. Switch the ground lead. This will allow you to run with ABS off, or to give it a quick reset [on/off] when it gets confused and throws the 'I quit' light.

Please don't run power circuits through any kind of twisted pair cable. Ever.

924RACR

You'll want twisted pair for the wheel speed sensors, to cut down noise. Can be pretty small, 20 ga or whatever - it's just a sensor signal.

Though I agree w/ Tony re: power wires etc. My comment was only related to connecting the sensors with the ECU.

Sorry, couldn't get back sooner - rennlist bandwidth has been sucking wind badly recently...

Geoffrey

Actually, you do want to twist power and ground together to reduce the noise. I use 1 twist per 25mm.

Oh, I thought 20ga was pretty large. LOL

Nader Fotouhi

I have a toggle switch on my S2 to reset the ABS when it shuts off on track. I know nothing about wiring, so I'll leave that up to others to discuss. However, I suggest that if you install one, put the switch up high within both reach and preferral view of the driver. At the Glen CR, I had to feel around to find the botton as I was doing coming out of the bus stop. Planning to move it to the dash with nothing else around it.

BTW, I realize this is not what should happen on a 944, but my rear wheels lock up when my ABS shuts off.

924RACR

Well, if you're running the different prop valve, and have changed pad compounds from stock... yes, you can get the rears to lock first.

Oddjob

This is where I ended up installing the shutoff switch. Made these notes at the time so I wouldn't forget, just took me awhile to find it...

Lemming

Excellent. I just ran the wires from the 4 sensors yesterday. Will finish the wiring when I start on the dash next week.

Oddjob

Tim - if you dont have the full wiring schematic, I can send it to you.

Lemming

I've got it, thanks. Waiting on a relay from rock auto.