VB Switches...
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salvageV6
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If you use the stock N/C switches to ground, you can use a SPDT, DPDT, 12 volt relay from radio shack to make a reversing switch.
IGN power to one side of the coil, ground via your 3rd, or 4th gear switch to the other side of the coil, N/C relay contact would be the switch you would use now to put power to your circuit with IGN +12 or a ground depending upon what you want to switch going to the common of the relay.
Could use the N/O contact of the relay to indicate NOT in 3rd or 4th gear or the relay is powered ON.
275-218 for higher current switching
275-206 for lower 3A switching and lower coil current draw as well and it comes with a socket.
Two relays needed for 3rd and 4th. One per circuit.
IGN power to one side of the coil, ground via your 3rd, or 4th gear switch to the other side of the coil, N/C relay contact would be the switch you would use now to put power to your circuit with IGN +12 or a ground depending upon what you want to switch going to the common of the relay.
Could use the N/O contact of the relay to indicate NOT in 3rd or 4th gear or the relay is powered ON.
275-218 for higher current switching
275-206 for lower 3A switching and lower coil current draw as well and it comes with a socket.
Two relays needed for 3rd and 4th. One per circuit.
You confused me. I thought the switches were "active" ground. Not meaning to hijack this thread, but please clerify.
Example, what signal should I see on the 3rd gear wire out of the tranny to the ECM, when it goes into 3rd gear? high, or ground?
salvageV6
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Dave according to the service manual for the ECM for the Turbo cars, page 8A-21, the switch is shown N/C to ground, and the wording says: open in 3rd gear, and the other one says, open in 4th gear.
Since the ECM has a pullup resistor to +12 shown inside the box for those inputs I would assume with a digital voltmeter you would read +12 on the line when the circuit opened the ground connection upon activation of the switch and that particular gear.
That's what I was going off of, as well as what the original poster mentioned for circuitry he was using and needed a wiring scheme for.
I haven't measured the voltages however on those lines.
You also shouldn't use the +12 through the pull up resistor to try to activate the relay as that may draw too much current from the ECM, the ground relay activation is okay since the switch is providing the additional current needed to run it, I believe they can handle it, perhaps a rating from one of the tranny guys on those switches could be given here, spec.s. and all.
Since the ECM has a pullup resistor to +12 shown inside the box for those inputs I would assume with a digital voltmeter you would read +12 on the line when the circuit opened the ground connection upon activation of the switch and that particular gear.
That's what I was going off of, as well as what the original poster mentioned for circuitry he was using and needed a wiring scheme for.
I haven't measured the voltages however on those lines.
You also shouldn't use the +12 through the pull up resistor to try to activate the relay as that may draw too much current from the ECM, the ground relay activation is okay since the switch is providing the additional current needed to run it, I believe they can handle it, perhaps a rating from one of the tranny guys on those switches could be given here, spec.s. and all.
Hmm, two different answers. I'll have to try and figure a way to hook a voltmeter to that line reliably enough to get a reading while driving and waiting for it to go into 3rd. Trying to figure out how to configure the AUX input on my Tranlator Pro to monitor the 3rd gear wire to pull some boost in high gears, like the stock chips do.
Dave, just pull the plug off the transmission and ohm out the switches with the engine off - they are both shorted to ground which confirms the n/c operation. There are 4 pins on the connector. Two are connected together through the tcc solenoid coil so somewhere between 25 and 100 ohms, and no connection to the trans case. The other two pins are the switches and both should show shorted to the trans case. No need to check when actually in 3rd or 4th 
.
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salvageV6
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It's a higher voltage through the ECM electronics and pull up circuitry, actual voltage could be +12 or perhaps slightly lower.
I assume the data logger is a high impedance device and won't load down the ECM circuitry, I guess you are as well.....
Actual input impedance/resisitance specs. on the logger should be checked if available.
It should work just fine most likely.
I only saw one answer in this thread?
Chris mentioned switches out of the 700 tranny not a 2004R.
I assume the data logger is a high impedance device and won't load down the ECM circuitry, I guess you are as well.....
Actual input impedance/resisitance specs. on the logger should be checked if available.
It should work just fine most likely.
I only saw one answer in this thread?
Chris mentioned switches out of the 700 tranny not a 2004R.
Yes, I'm pretty sure that the inputs on the Translator Pro are high impedence inputs. It's a programmable input that can look for a V+ (5-15v), or a ground.
I only saw one answer in this thread?
Chris mentioned switches out of the 700 tranny not a 2004R.
That was my point of confusion then. I assumed that the two would have the same "scheme".
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