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Manual using Auto what size resistors and applying the idea to other transmissions.


crownin round

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Ok so below is the basic circuit that has been used to manualise an h shifter and manualise a 12v automatic patrol. I want to know a few things. How would I calculate what size resistors to use in the unmentioned points down the bottom.

Pretty much it is on a switch that locks up the torque converter lock up and uses an electric foot switch to disengage it and shift gears.

I want to know how I would calculate what size resistors I would use in my 24v safari. It is the same trans but different voltage solenoids.

I really like the ability to run both auto and manual. I was wondering if something this simple could be adapted to be used with say a toyota trans or other trans all the time so that the use of a trans controlling ecu wasn't required.

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I am not sure how you would do it so you can select auto or manual BUT I made my safari manually shifted and it was pretty damn easy.

I wrote on OFFROADEXPRESS about the process years ago.

I just had a series of relays switched by the inhibitor switch.

Cut the line pressure solenoid wire.

Add a manual lockup switch.

Easy peasy. Don't know why you'd want to add resistors and once you have shifted it manually you won't want to put it back to auto anyway

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If there is only a relay coil in series with each circuit, measure the resistance of the coil, and add similar in series. You'll need to calc the power for the resistor. e.g. volts (12 hopefully) x amps (e.g. 12V / 200R =  0.06A = 60ma. So 12V x 0.06 = 0.72W. Use a 3 - 5W resistor so it runs cooler.

 

If you want to get the same current in each circuit, just double the R, i.e. i(current) = V / R. What's the 26R resistors? Will the computer be running off 12V still? Is that why you'll not change them?

 

Prolly need more detail on the connections of the "DPDT" relays. It's not clear who's switching whom. Also, it's a little unclear which lines are inputs/outputs. e.g. does "From manual shifter" supply a voltage (12V, 24V) or switch to earth (depends on how the DPDT relay is connected)?

 

This doesn't take into account any voltage sensitive parts. Bear in mind your 24V patrol will charge old batteries at 2x 14.5V = 29V, more for calcium batteries, and short spikes of many more volts when things turn off / jump starting.

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