SC temp gauge sender

Bones · Bones's Garage

Hi guys ...anyone know (for definite) where the sender for the temp' gauge in a '78 SC Sportomatic is located . I am a litle confused as my car has a Sportomatic gearbox and I understand the temp may be picked up from a sender there. On the Sporto' gearboxes there is a switch which also switches the ignition circuit in (so the car can only be started in neutral or park). The reason the oil temp sender may be there is that the oil temp gauge in cars fitted with a Sporto' box takes it's reading from the gearbox oil temp as this temperature is vital to the performance of the torque converter. Cars fitted with the Sportomatic box also have a greater oil capacity to allow for the requirements of the torque converter.
I can't find any mention to the sender in manuals I've looked in although I'm sure it's in the factory manual which I don't have.

Jim Sims · 03-05-2003, 06:19 PM

It's screwed into a boss on the bell housing, passenger side, under the starter. The one with the wire terminal projecting forward is the temperature sender and the one on the other side of the boss with the wire terminal projecting rearward is a temperature switch. This is shown in the Haynes Porsche 911 Automotive Repair Manual. Cheers, Jim

Bones · Bones's Garage

Thanks Jim do you mean the torque converter housing as that's where it is displayed in my Haynes diagram that I eventually found?

Jim Sims · 03-06-2003, 05:42 AM

bell housing = torque converter housing Jim

Bones · Bones's Garage

ah!! thanks jim

jk911 · 05-22-2003, 10:08 PM

Im glad I found this post because I am puzzled my this unit !

As I was under my car pulling out the servo unit off my sportomatic I noticed a loose wire on the other side of the transmission just hanging down !

Its green and black in color. It looks as though it came off the temp sender unit.
It does !

my temperature gauge doesn't work !

My question is I don't know how it connect it to the gauge i.e the green and black wire has a central wire and on outer braided like wire (do you get what I mean?)

Also the temperature unit already has one wire connected to it !

Any advice, guidance, photo's or diagrams would be greatly appreciated .

Thanks in advance .

Jim Sims · 05:34 AM

There are two electrical items on the side of the torque converter; a temperature switch and an oil temperature sender (see above). The green and black wire goes to the oil temperature sending unit; the one with the terminals pointing forward. I think the outer braiding is a fiberglass like sheath that provides thermal protection to the inner wire electrical insulation. The green and black wire should terminate in a metal connector or lug that slides onto the flat terminal head projecting out of the oil temperature sending unit. Cheers, Jim

jk911 · 05-22-2003, 11:08 PM

Thanks for that Jim.

Even though I can't visualise it in my head at the moment Im sure I will see what you mean when I have a look at it under the car.

Do you know if there are any reference pictures on this board, I have tried looking but no success.

The wire apears to have been cut bluntly as the ends are all tattered.

So when you say "metal connector or lug that slides onto the flat terminal head projecting out " Im a little unclear on this .

Like I said it will probably make sense when I look at it .

Thank you

jk911 · 05-22-2003, 11:33 PM

Would you be able to point them out in this diagram if they are there

Is this what the sending unit looks like ?

Jim Sims · 05-23-2003, 05:57 AM

Item 32 (PN 901.641.632.00) is the temperature sender; item 30 (PN 905.613.102.04) is the temperature switch. If you ever need to replace these the metal gaskets (items 31) are PN 900.123.007.30 The colored image appears to be a temperature switch out of an earlier model of the sportomatic transmission; see the Haynes manual page 130, figure 5.66. The temperature sender has a head terminal that looks a bit like a "mushroom"; the connector or lug that should be on the wire is like a flattened "C". The opening of the "C" slides under the "mushroom". Look at the end of the temperature sender; there is a possibility the connector or lug is still there. You can solder or recrimp it back onto the wire. It appears your temperature switch (the one pointing backwards) has two such "mushroom" terminals that project to each side with each one connecting to a different wire. Cheers, Jim