Holden VN Calais V8 into HQ One Tonner, auto gearbox wiring?

[ProZac]

G'day all.

I'm helping a mate with the wiring for this conversion. The engine side of things is all wired up, and the motor has been started, runs sweet. We're tidying up the wiring at the moment, and getting things more permanent and looking forward to the first drive/skid. I've figured out the park/neutral lock-out switch for starting, and the reverse light switch also, no problems there. Where I am a little stuck however, is the speedo sensor. Its a 3 wire, so im assuming hall effect, thus Power, Ground, and a signal output. I think I've figured out the pinout for it, but i'll take a scope with me tomorrow and double check it.

As the motor is out of a Vn Calais, the trans is apparently an electronically controlled 4 speed auto, th700.... I'm not really up with the play on auto transmissions at all.

My first question is, should the trans have a seperate transmission control ECU, or is it more likely the main engine ECU will also control the auto? If its controlled by the main engine ECU, I should be hooking the speedo sensor directly the the main engine ECU, and not somewhere else first... The vehicle the engine and loom came out of is still there, so i can trace stuff back if need be, but i was hoping to avoid it, as it'll mean removing the dash.

Hopefully someone out in OldSchool land has had some experience with this swap, or these transmissions, and can shed some light.

[KKtrips]

I am 99% sure these trannys don't have anything electronically controlled except the overdrive - though you can wire that into a switch on the dash.. The speedo drive is easy - just get a mechanical drive speedo head out of a TH700 and adapt to the original HQ setup.

Sorry I can't tell you specifics - fairly sure there will be some definitive info on the web though.

[Yammies]

if it's anything like the manual T5, the top half of the speedo drive comes off and there is a manual drive underneath it.

[ProZac]

Right,. got it sorted. Factory speedo sensor is a hall effect one, and wired like i thought, outputs 10 pulses per revolution. This is then divided down to 2 pulses per revolution by the factory speedometer, which is then fed to the vehicle main ECU, and used for engaging the lockup on the torque converter at speeds above 80 kmph.

For the interim, I'll just put a switch on the lockup so it can be engaged manually, and make my own pulse divider so the ECU can handle it later on down the track, along with monifying the speedo to be electric, so we wont even need a speedo cable.

k-trips, your totally correct, th700 is hydraulically shifted, so thats awesome