Reversing lights

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mefmotorsport
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Reversing lights

Post by mefmotorsport »

Now I have the Tractive sequential gearbox fitted with the gear displayed on the X dash via the DTA Canbus, I need to drive a relay to switch on my reversing lights when reverse is selected.

I was wondering if it would be possible to drive an analogue output to switch on only at the voltage in reverse from the gearbox potentiometer.

Maybe that's asking a bit too much, I might have to make a little circuit externally to detect reverse! I havn't checked yet to see what the voltage for reverse is.

Martin
stevieturbo
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Re: Reversing lights

Post by stevieturbo »

Not quite following the question. You want the gearbox to send the signal, or the ecu to operate the reversing lights ?

I take it there is no conventional switch at all ?

Unless you configured an Ana in and an Aux out, not really sure how else you would achieve it. As certainly as far as motion goes, the ecu would never know what direction the car is going.
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mefmotorsport
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Re: Reversing lights

Post by mefmotorsport »

There's no switch, the only way is to use the gearbox potentiometer signal to somehow drive a relay when the output voltage is ONLY that of reverse. I havn't checked the voltage yet but generally reverse gives the lowest voltage out as the gear order is R,N,1.2.3.4.5.6 .

So, as long as the ecu is powered up to provide the 5v ref signal I would need anything say less than 0.5v to put the reversing lights on or anything more than 0.5v to hold them off. Would have to gate it such that the lights didn't come on if the ecu was switched off!

Martin
x30xe
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Re: Reversing lights

Post by x30xe »

I assume you are talking about your rally car. Why on earth would it need a reverse light ? Does your local laws require it ?

Sorry this does not help regarding the actual issue.. but..
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mefmotorsport
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Re: Reversing lights

Post by mefmotorsport »

yes, rally cars have to pass the mot and be fully road legal, if they're fitted on the car normally then they have to be there and work.

martin
Basil
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Re: Reversing lights

Post by Basil »

Are you sure reversing lights are part of the UK MOT? I am in the motor trade and have taken countless cars and light vans and trucks for test, but never have I seen the tester check the reversing lights are operational. That aside I too have a Tractive sequential in a Skyline, so am interested in the replies. Does the X dash allow any output functions, I know most Motec ones do?
Antral
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Re: Reversing lights

Post by Antral »

You can drive a relay off ana 3 as well as using it for the gear pot ;) ;)
stevieturbo
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Re: Reversing lights

Post by stevieturbo »

Basil wrote:Are you sure reversing lights are part of the UK MOT? I am in the motor trade and have taken countless cars and light vans and trucks for test, but never have I seen the tester check the reversing lights are operational. That aside I too have a Tractive sequential in a Skyline, so am interested in the replies. Does the X dash allow any output functions, I know most Motec ones do?
Construction and use may require reversing lights in as much as if lights are fitted to a car, they must work.

But it is NOT an MOT test item ( same as gay front fogs )

Of course another option is a manual switch.
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mefmotorsport
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Re: Reversing lights

Post by mefmotorsport »

Antral wrote:You can drive a relay off ana 3 as well as using it for the gear pot ;) ;)
How will that work, surely analogue 3 is an input not an output? It would need to work a separate output to drive the relay?

Martin
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mefmotorsport
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Re: Reversing lights

Post by mefmotorsport »

I think I have sussed it, use ana3 and enable aux3, set duty cycle to 100% ONLY at the voltage coming in on ana3 when in reverse gear. Ana3 will still provide gear info for the X dash.

Martin
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