Porsche 944 LSx Wiring
Last couple of weeks I have been slowly tinkering with building the wiring for the car from scratch. No original wiring left in the car, everything was removed, and I am wiring only the things I need/want. It is very time consuming, and reading wiring diagrams is repetitive, but also a lot of fun to be able to build from scratch!
Figured out a mounting solution for the larger LSX computer in the stock location. Wish I had not have ordered the wiring harness from the engine quite so long, but it would be a major project to shorten it, so I’ll just have to deal with some extra slack.
Once the ECU’s location was determined, then I could start wiring a few loose ends on the fuse panel as it does connect directly to the ECU.
And after enough digging, found the solution to running the OEM gauge cluster. I was debating building a custom dash and using custom gauges, but really liked the idea of keeping the original cluster/dash assembly. It won’t be easy to wire everything up that I need to the cluster, but I think the result will be better. Since the VDO gauges use some special resistances for it’s sensors, the OE LSx sensors will not work with them, so I added a VDO oil pressure sensor similar in design to the 944 sensor using an LS1 adapter from Speedway motors.
Temp sensor is the same deal, again, using a custom adapter from Summit racing, and an early 944 temp sensor. The only thing you lose going this route is the warning red temp light. Simple plug and play in the passenger side coolant port.
Then I tackled getting all the wiring built and run from the front of the car for turn signals and parking lights. That all went pretty easy. The power probe III that I have discussed before is invaluable for this type of work as you can apply power and ground to a component to make sure you have the wiring correct. For the flasher component of the turn signal, I used a simple 2 prong flasher relay inline, all wired into the stock turn signal assembly. Easy pleasy.
Building the harness from the wiper stalk to the wiper motor was very similar. Using the power probe, I could find my low and high wiper signals and wire that appropriately to the OE wiper stalk. The overspray on the wiper motor arm is going to bug me, so I’ll pull that off quick and put it in the bead blaster to clean it up.
And a pile of wiring come out underneath the dash. Making my own wiring diagrams as I go.
Wiring ready for install on the 2 sensors I installed on the motor, but I ran out of cable sheathing, so I have some more on order. I like using a good quality mesh sheathing rather than the cheap stuff you can at the parts store. The cost is similar, but the quality much better when ordering online in bulk.
With a very general idea of switches I would need, I build a switch panel. Well….I ordered a switch panel which came completely disassembled, so I had to put the entire thing together and wire it. I figured that would take about 15 minutes, yet about 3 hours later I was finally done. It now houses a main ignition switch, starter button, two accessory switches, light switch, and one blank which will get used likely for a cool shirt power feed.
And the switch panel mounted along with a trim strip for the lower dash. I still need to reinforce the bottom of the dash to the firewall so it doesn’t flex at all, but that won’t take long. I’ve been kicking around the mounting for about 2 weeks now, which was holding all the other wiring up, so I finally figured out a simple, yet functional solution. Now I can start hooking up components much faster.
Next up I need to cut a plate to block off the original blower motor location, finish connecting components to the dash switches, and then start wiring up the gauge cluster. That should be time consuming. Once the cluster is hooked up and functional, I should be able to start cranking the motor to build oil pressure.