Gonna pin out my OEM stalk now that it’s on the bench.
Looking at the “normally open switch” it appears that the Rostra unit is always on, when you hit the momentary switch on the end of the “normally open switch stalk” the button momentarily contacts the internal off switch wire. Going to create a schematic tomorrow! Might be able to use the OEM switch!

Ok,Thought this wanna be a matter of pin in/outs. Monkey wrench into the mix! Electron heads any bright ideas?
I thought it was gonna a matter of moving a contact on the switch from n/c to n/o.
This is the back of the OEM switch:
http://forums.pelicanparts.com/uploa...1552428840.jpg

http://forums.pelicanparts.com/uploa...1552428840.jpg

http://forums.pelicanparts.com/uploa...1552428840.jpg
Here is the back of the Rostra, another set of circuit boards! Two of the little buggers are just switch points for the top and bottom pads, the end is just for the momentary switch and the big sucker is so they can keep it proprietary. since the end switch is just a momentary for on and off, I was thinkin', since that stupid little box is just for on/off it doesn't really have to be on the steering stalk. the wires to the other 2 switches, while on boards they are not connected to the wiring on the circuit board in any way. so the good news is the wires from the OEM stalk switch could be used instead of the Rostra stalk switch and the Rostra board could be attached to the old cut up board with standoffs and inserted into the cut down can and wired as I originally planned.
Can any electron heads identify the visible components on the big board to determine their function. Static sensitive?

http://forums.pelicanparts.com/uploa...1552428840.jpg

http://forums.pelicanparts.com/uploa...1552428840.jpg
http://forums.pelicanparts.com/uploa...1552428840.jpg
http://forums.pelicanparts.com/uploa...1552428840.jpg

You guys use cruise control in autocrosses or track days?

TSD rallies are competition. Easy to pick up wheel speed using inductive (I think, not resistive or optical any way) sensors which read the passing of CV bolts.

To and fro.....

Got a mad plan. It involves a hot knife and soldering iron. I an going to mount the Rostra stalk switch in my cut down can. After removing the metal mount and drilling mounting holes in the top so I can use longer screws to mount it to the can top. All wiring and switches will remain in place. And soldered to the appropriate pins in the old can.
The single perplexing issue was how to use the OEM switch as an all open switch. If you look at the rear center contact you can see a “V” shaped momentary contact resting on the + wire contact. I propose drilling a hole perpendicular to the “V” contact threading the contact for a tiny machine screw, who’s tip will be ground to the same angle as the “V” contact and thread it in so it hold off of the contact by a couple of mm then attaching the brown wire to it thus enabling shutting off the Rostra using the designed method.

http://forums.pelicanparts.com/uploa...1552428840.jpg

Finding those circuit boards was actually a minor blessing causing a rethink and resultant solution. I am sure that this will allow the install without cutting or altering the main harness, making it 100% reversible.
Further onto the quest!

As you can see, I modified a switch I got off of eBay. Now all resting positions are normally open. The grey wire pulls the Rostra red wire which is 12v, to disengage the unit. Started installing the components, engine bay, to the frunk is complete. Tomorrow will be the day of reckoning, lots of caveman circuit design. The biggest time sink was tracing the wiring and integrating the OEM switch into the plan.


http://forums.pelicanparts.com/uploa...1553136021.jpg


http://forums.pelicanparts.com/uploa...1553136021.jpg


Switch pulled to disengage:
http://forums.pelicanparts.com/uploa...1553136021.jpg

Switch in the resting, normally open position:
http://forums.pelicanparts.com/uploa...1553136021.jpg
Potting material, to help vibration proof and insulate the screw and wire.
http://forums.pelicanparts.com/uploa...1553136021.jpg

Nice work. Following closely.
Johan

Cool stuff Eric. Glad to see this thread got back on track. Big thanks to jaustinmd (the OP) for diving into this and making a schematic and guide. This worked like a charm and saved us all from a lot of work to get the settings right! I also added the relay so the violet wire sees ground (I’m running LED brake lights.) Also a key item that the OEM clutch switch works to disengage the cruise as the OP wired it.

In my case I went over to ITB’s and EFI, and completely re-did my engine bay. So I wanted a fresh new electronic system without a vacuum servo. My choice.

Now that I have the cruise working well, I am also thinking about getting the OEM switch to trigger the Rostra... a project for another day.

NOTE: The dip switch settings worked fine, but I found that low gain (low sensitivity) worked better then mid-gain in my situation with the ITBs. No surging. It was also important to get almost all the slack out of the Rostra cable.

Mounted the Rostra unit as others have done:

http://forums.pelicanparts.com/uploa...1586626141.jpg


Throttle arm connection:

http://forums.pelicanparts.com/uploa...1586626141.jpg


Gratuitous engine bay pic SmileWavy

http://forums.pelicanparts.com/uploa...1586626141.jpg

SUCCESS! I now have the OEM cruise stalk fully controlling the Rostra cruise unit.

First, hats off to Eric (ClickClickBoom) for the genius method of making the "cancel" contact of the OEM switch N.O. (Normally Open.) A couple quick cuts with the Dremel, and an added screw, and bingo! A brilliant and creative solution, I think he's lying about the caveman hammer thing.

In my case, I'm running the Rostra RF wireless switch shown a couple pages back. This works just fine, but the possibility of getting the OEM stalk to control it was just too much temptation for an incurable tinkerer like me to handle. Had to be done! An important distinction here is that I opted to have the "cancel" feature of the stalk trip the cruise control (tempostat) relay. This disengages the cruise just as would happen if you pushed the clutch pedal, and allows you to resume the previously set speed. In other words, I didn't want the "cancel" to turn the whole unit off requiring a new power up and reset of speed.

Bottom line: was it a lot of work? Yes. Did it make me happy? YES! I push the stalk down to set a speed, or hold it down for decel. Pulling the stalk upwards resumes the previously set speed or I can hold it up for accel. Pulling back cancels the cruise until I want to reset it again. The Rostra unit is on by default when you turn on the ignition, so I don't really care about an off button. Now the wireless unit is hidden under the dash, so no one even knows its there, and the cruise stalk works great!


Some technical bits and pictures:

I haven't seen the inside of the other switches Rostra offers but the wireless version is an open circuit design. As with many of these types of remotes (like garage door openers) there is a common connection to the buttons, and then one connection each for their operation. Pressing a button connects common with the connection that actuates a function. So I've added a few wires in parallel with the buttons so I can use the external (in this case OEM) switch to make the momentary connections.


Here is the wireless 2 button unit, made to mount in a steering wheel normally:

http://forums.pelicanparts.com/uploa...1586880392.jpg


What it looks like inside, with my labels:

http://forums.pelicanparts.com/uploa...1586881412.jpg


And here with a few wires so I can run the OEM cruise stalk switches in parallel:

http://forums.pelicanparts.com/uploa...1586881467.jpg


This is how I wired it up, after hacking the switch. I had to add one more wire to the OEM switch for a total of 5. Please pay attention to my note about separating the black wires at the OEM cruise connector-- one carries +12V from the fuse box and you definitely want to clip both of those wires at the connector and isolate the one with voltage. The other goes to the stalk switch.


http://forums.pelicanparts.com/uploa...1586881698.jpg


That book that begins with a "B" had errors. Switch must be hacked for 3 N.O. contacts, normally there is one N.C. Here you can see the black wires I mentioned above, definitely get 12V disconnected if you're going to make these mods. Don't blame me if you fry something. SmileWavy

http://forums.pelicanparts.com/uploa...1586881698.jpg