Need help: Clutch Safety Switch Wiring

YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Need a bit of help. I bought a '91 Supra that was converted to a 5spd transmission by the PO. I need to return the clutch safety switches back to normal for an inspection before I can license the car. The problem I'm having is am not sure how they are supposed to be wired. I have been reading a lot of the TSRM and it isn't very clear. From what I can gather, there are two switches on the clutch. One that is depressed as you press the clutch in all the way that allows you to start the car and another switch that if you press in the clutch will cut out the cruise control.

I think the Cruise control safety switch is wired to the cruise control ECU, but I'm not 100% certain.

The safety start switch I have no idea where it goes.

Any help would be appreciated. If anyone has their interior apart and can take some pictures, that would be great.
Thanks!
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Hi Jetjock,
Thanks for the links. I have to admit though, I'm not very good at reading these diagrams properly...maybe you can elaborate on what I think I am seeing below.

From what I can gather for the Clutch Start Switch:
-There is a Black/Yellow wire(s) (one Black, one yellow or is it 1 wire that is black and yellow) going TO the switch and a black wire(s) FROM the switch
-The B/Y wire(s) is connected to the starter relay which I think is in the engine compartment (I can confirm later in the TSRM I have).
-The Black wire(s) is connected to the ignition switch which I think the harness is attached to the turn signal stock, or maybe directly to the ignition (can't remember, I had some of this apart already)?
-I do remember seeing a black wire under my dash that had a light bulb attached to it so I'll have to trace that back to see where it leads to (which to me seems very out of place). If it goes to the ignition it might be my wire (although I think I would need two wires?).

The Cruise Switch:
-There is a Black/Yellow wire(s) connected to the clutch switch and the Cruise Control ECU. I will try and pull the CC ECU tonight and have a look.
-There is a Blue/L (what color is L?) wire(s) leaving the clutch switch that is connected to the starter?

Am I reading this right?

Is the wire harness that plugs into the switches include the to and from wires? When the clutch is depressed it closes a circuit allowing the connection between the two wires (i.e. B/Y to B/L for the cruise switch)?
Thanks!
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Oh, and to add to the confusion, my car used to be an Auto, so my wire colors are probably different too, doh!
 
hvyman

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
1 is black yellow and the other is black. doesnt matter which way they go on the switch.

the cruise control shouldnt be needed for an inspection i wouldnt think. its an option not a safety component.
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Had a closer look last night and the color of the wire from the cruise control ECU is purple with a grey dash on it (pin 11). Pin 11 is one of the wires that goes to the cruise control clutch switch according to tsrm. In the diagram from Cygnus it appears to denote a different color. Anyone know what the notations on the diagrams in jetjocks post above mean by chance? Another oddity is TSRM denotes an 18 pin harness where as my car has 19 wires (shows 20 pins in the picture) View attachment 74756View attachment 74757


Sent from my iPhone using Tapatalk
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
I figured out that there are different cruise ECU's out there. Wonder if pin 11 is still the right one with the version I have?


Sent from my iPhone using Tapatalk
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
I'm wondering what the notations mean that are highlighted in yellow (for the clutch starter switch wiring system). I'm kind of assuming that if I cut the wire to pin 7 of Ignition Switch and run my own wire to the clutch start switch, then cut the wire at pin 1 of the Starter Relay and again run my own wire to the Clutch start switch that this will complete my circuit I need for having my clutch starter switch operational? I am not sure what a 4 with a circle means? Am I on the right track?
Thanks for the help guys, really appreciate it. I'm pretty new to wiring these sorts of things (obviously).

Capture.JPG
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
3p141592654;2030954 said:
The general consensus is the TEWD is for a 1990. Even so, so me of my 1990 wiring doesn't match perfectly.
Click to expand...

In the case of my cruise ECU, would you go by wire color or pin? Just curious how you'd narrow this down. I suppose I can test the circuit using my volt meter. If I get voltage at pin 11 I know it's not the right pin.
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Looking again, I think I'd have to tap into the wire that is coming out of Pin 7 rather than cut it and run a new wire...? :s
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
YYCSupra;2030960 said:
Looking again, I think I'd have to tap into the wire that is coming out of Pin 7 rather than cut it and run a new wire...? :s
Click to expand...

Correct, don't cut that or you will run the full starter relay current through the interlock relay winding, and then your would have to do the starter relay mod next :: facepalm ::
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Stupid question alert but where could I buy a wiring book specifically for a '91 supra? Ditto for TSRM.


Sent from my iPhone using Tapatalk
 
YYCSupra

YYCSupra

Getting back in the game
Aug 4, 2014
128
0
0
Alberta
Cruise Control 91.JPG
Nice, bought both the TSRM and Wiring Diagram for a 1991 supra, perfect! It's funny, on one of the ads they opened the book and it just so happened to land on the Cruise Control wiring page. Here is a screen shot of the picture. Definitely different from a 1989 or 1990 for that matter.
 
You must log in or register to reply here.
Top Bottom