I have '75 1.8 that the PO installed a nice center console complete with gauges. The volt meter works, clock didn't until I pulled it out and found the ground wire disconnnected. Now it keeps perfect time.

There is a plate currently where the oil temp sending unit goes. I also have a oil temp sending unit. I believe the order of installation is the red o-ring, the sending unit itself, the gasket and then black cover. I'm assuming I ground the black cover and the lead from the gauge goes to the sending unit.

I can't seem to locate that wire. I'm assuming that the oil temp lead goes thru the center tunnel into the engine compartment. Where should I look? Will a ground wire also be with it? What color should the wires be? Brown=ground?



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There should only be one wire for the temp gauge, you can run one yourself.

Ground is the chassie.

I was hoping there was a wire in the engine compartment. I'm trying to avoid pulling out the center console. The PO installed a Rennshifter and it looks like the only way to remove the console is to first remove the Rennshifter. I'm not sure how much readjusting is involved with re-installing the shifter.

If the gauge is already wired using the factory harness, then the lead wire must be somewhere.

Not sure if the 75 loom had the wire run for it or not. If you did not have a console,

like my 72, I had to run a wire. Use a few wood blocks to lift your console up high

enough to run the wire. Leave the linkage alone if you can.

I added an oil temp gauge in my 71 and found that a wire did exist in the interior that went to the relay board. I didn't think 71's even had the center console. The wire was under the shifter carpet right by the shifter. After looking through the schematic, the wire was for a temperature sender. I think the wire was brown.

The wire continued across the relay board to the engine connector but the connector to the engine did not have a wire at that position. So I grabbed an extra engine wire harness and pulled a contact out and wired from engine connector to taco plate.

Spoke

The green/black wire comes up through the body below the battery, and should have a rectangular translucent plastic insulator over the male connector. From there, your connecting wire goes through the throttle cable hole, and across the lower front of the engine to the sender. It's held in place by a couple of small brackets similar to the one on the cover. DO NOT forget the special 6mm crush washers for the bolts holding the sender assembly to the engine case.

The Cap'n

So the green/black wire from inside the car to below the battery should be present (in theory)? Should my local Porsche dealer have the appropriate crush washers ? I also noticed my drain plug did not have a crush washer. That is bad, right? There is no oil leaking currently.

While they won't have the washers in stock, I'm sure they can order them. Yes, a crush washer on the drain plug, as well as one on the sump nut. ALL crush washers are installed with the split side toward the head of the bolt/nut. The Cap'n

Can a generic crush washer be used? If so, where might I purchase one? Should a new washer be used after each oil change (I'm guessing yes)?

Sure, if you can find generic metric crush washers of the correct diameters, and if they're of the proper design.

The Cap'n

Just ordered the oil drain plug washers ($.88 each) and "taco plate" washers ($1.19 each) from my local Porsche dealer. Cheap insurance.

3 questions for y'all who are following this thread .

1 - Does anyone have a picture of the actual installation of the sending unit on the taco plate ?

2 - Does anyone have any pictures of the routing of the wireloom in the engine compartment from the firewall back to the sending unit ?

3 - Would it not be easier to route the wire from the indicator under the carpeting along the tunnel and drill a hole in thefireewall using a rubber grommet to allow the wire to pass thru it ?


Thanks .

I'll will document the installation of mine. In my case, the gauge is already hooked up to the factory wiring harness, so it's just a matter of finding where the black/green wire is in the engine compartment. I believe the Capt'n was responding to those who already have the wiring in place. I think the olders car didn't come pre-wired like the newer ones.

I found the wire next to the resistor pack below the battery, just where it was supposed to be. I finally got the crush washers for the 2 bolts and the aluminum washer for the sensor itself. Last night I hooked up the sensor outside the car and put it in near-boiling water and the gauge needle responded.

My next question is do I need the black outer plate. It seems to have a place for a ground wire to be inserted, but I would think that if the sensor and inner plate were installed, the sensor would already be grounded. Do I need the black plate and gasket installed to keep the oil in the engine??

I do not recall that, but there were some tabs I believe that bent over and held the wire.

The sender is the variable ground for the guage. The ground for the sensor is the taco plate assembly and the two attaching fastners. A single wire from the sender, across the front of the engine to the connector under the battery. That's it.

Ahhhh, the metal tab on the black outer plate holds the wire going to the sensor. I'll post some pictures once I install it this weekend.

Someone wanted pictures of this procedure so here they are. I ran a wire from the engine bay down through the grommet along side the accel cable, then across to the drivers side and through the hole in the engine mount crossbar where the shifter lingage goes through.

I removed the old plate. Below are the new plate with sensor attached (don't forget the alum washer) and the old plate.

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Here is a shot of the engine with the plate removed.

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Here is the new plate installed. I used new crush washers for the two bolts and a new o-ring. I put a small film of oil on the o-ring before installing. The sensor itself points to the rear of the car. I zip-tied the wire to the small bracket coming off the outer plate.

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might not be ideal to route the wire through the hole for the shift rod but other than that, looks good!

Andy

Guys, I think I posted pics of the wire routing in an old thread... There are clips on the front of the motor and maybe on the bottom of the oil cooler, but I don't seem to have the pics anymore, sorry!

I'm dropping the motor this winter in order to clean up the engine bay and treat some rust issues, so I figured I'd just run the wire through there for now. I have it zip-tied so it can't make contact with the shift rod or abrade against the engine mount.

My oil temp gauge is a VDO but without the numbered temps on the face, just a red zone on the right. Since installing the oil temp sensor, the needle on the gauge hasn't gone past the letter "E" in the word "TEMP" on the face of the gauge (ie: it hasn't reached 12 o'clock). Is this normal, assuming the engine is in proper working order and all the engine tin and seals are in place?

That's about right. Mine runs between the "T" and the "E", even on hot days here in Texas. If you search, I seem to remember a thread where someone had done a conversion that had shown the actual temps for each letter on that gauge.