Wiring diagram for Trans

72 super|vert|stick · 14 July 2010, 05:03

I was wondering if anyone can help with the wiring for my transmission. A 72 with 2 temp sensors, I believe they both sensors say a 140º F-?C. Are they different temp. ranges for each sensor, and which range is what on the Bellhousing? I want the car right, but also want to pick the right battles. Far as I know i never saw a working light, and after seeing the PO's wiring, don't even know if it was hooked up.

Is the setup the 2 sensor leads run to the three way switch one goes out to dash light?
I know the switch has markings.

Hopefully my wife is wrong, and I can communicate what I'm saying in my questions. Just need some guidance on small details.

Bookwus · 14 July 2010, 05:18

Hiya 72,

OK try this for starters...........

Point your browser at www.vintagebus.com
Click on the wiring diagrams link on the left side of the screen
Find 1970 Bug
Click on the green circle labled #2

That should bring up a wiring diagram for the 2 sensor set-up.

Now, do know the sensors are not the same. One does register at 140. The other should register at 125.

72 super|vert|stick · 14 July 2010, 06:33

Bookwus,
Thanks for the quick response. And Also let me say thanks to you and the others who keep information flowing on our subject. Your tutorial on the engine rebuild was essential for me getting a running motor. I have the 4 ref books and yours is what worked.

Back on track, I guess my wife was right. My plastic connection piece is missing so I will have to put my touch in making the switch work. I know the switch has a markings of T1,T2, and K. Assuming T1 is lower range (125)? T2 High Range (140)? and K is the out lead? Can you test the switch on an VM and see if its working? And how if you would be so kind, Limited skills on VM.

Chris

volkenstein · 14 July 2010, 10:18

Chris,
Does your VM have a self power capability? Got a continuity circuit tester. I guess an el-cheapo method is to run a + lead to K and a light hooked in to the -lead wire. IIRC (I'll have to look later) it is the shift rod (internal) which determines the selection. Your lower temp (125) is for R2, 140 for R3. You can play around etc checking the circuit. Bit of a hot temp (it's degrees Celcius) to test the senders themselves but at least you can verify most of the temp circuit.

I have forgotten how I checked my spare.....

Regards
Sean

Airhead · 14 July 2010, 10:51

This topic interests me too, I have a 1970-71 wiring diagram for my KG, my transmission has 2 ATF temp switches but only one is shown on the wiring diagram (F13),

I suspect mine has never been working, would like to sort it out.

Thanks

Airhead

72 super|vert|stick · 14 July 2010, 16:26

Sean,
I do have a self power capability. Again I messed around with it and was able to get it to read a very small amount. With limited skills on VM not really sure it I was reading anything useful. Do the sensors in the bellhousing matter where they are seated? When you said "Your lower temp (125) is for R2, 140 for R3." I have a T1,T2 and K on the switch. What is R2,R3? Did you mean T1,T2? I'm a newbie, and the learning curve is still pretty steep right now.

Thanks
Chris

volkenstein · 15 July 2010, 07:41

Testing my faulty memory!

,
Position doesn't matter as they are in the same gallery, although the 125 one goes to the inside, 140 outside. Now...I'm at work so haven't got manuals on hand, but either way when you select gear R2, then the 125 sensor should be active. Select the R3 gear and the 140 one should be active. It is actually a complicated little circuit as far as everything working correctly (warning light included) goes. I suspect (can check at home) T1 on the switch goes to the 125 sensor, T2 to the 140 one. IIRC (even more shakier now

) the plug only goes on one way, so I should be able to check. The K terminal goes back to the warning light.

Steve,
Look at a '69/'70 Autostick beetle diagram for the twin senders.

HTH
Sean

72 super|vert|stick · 15 July 2010, 17:52

Sean,
Thanks for the information. I will give it a shot. With my plug missing I have to create it with terminals. I will let you if it works out.

Chris

68autobug · 21 July 2010, 11:19

Hi Guys,

Yes, Sean, a complicated little system...

which was then changed as a sensor on D2 wasn't needed...

I always thought it would have been Much easier to use two lights in the speedo or dash.. lol
than to "invent" the D1 & D2 switch....
then to find out later it wasn't needed...

cheers

Lee Noonan