12v only in first gear (auto)

denpo

denpo

Carburated Nihilist
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Montreal, QC
I want to power a device only when the car is in first gear.
Is there somewhere I could tap in the harness to achieve this (I'm pretty sure the answer is no).
Otherwise I'll use light or Hall effect sensor, but I want to be sure there is no simpler way.
 
Radio Shack, burgler alarm magnetic switch and contactor, they are LO current, so they trigger a small 12 volt relay....it's what senses my backup lights on the 200 4r conversion....

told you I was a geek....


:clap:
 
Well, I was ready to pull out some circuit, but good call on the reuse of readymade cheap item.
Geeky and ghetto* (hence the 'fro)

*in a good way of course :drink:
 
Rod75 said:
You could also use a microswitch with a lever arm for actuation. Something like this: http://www.everythingcarts.com/p-1330-ezgo-roller-arm-micro-switch.aspx
You could mount it beside the shift lever (position in 1st) in console?
Click to expand...
Yep, that THE other option.
On one hand much simpler if the switch can handle the amp of the device (I it does) you save a relay.
On the other hand you have to have some sort of mechanical setup, that must be precise, smooth and "rugged" at the same time.
I'm gonna give this option a second thought. Thanks
 
denpo said:
Rod75 said:
You could also use a microswitch with a lever arm for actuation. Something like this: http://www.everythingcarts.com/p-1330-ezgo-roller-arm-micro-switch.aspx
You could mount it beside the shift lever (position in 1st) in console?
Click to expand...
Yep, that THE other option.
On one hand much simpler if the switch can handle the amp of the device (I it does) you save a relay.
On the other hand you have to have some sort of mechanical setup, that must be precise, smooth and "rugged" at the same time.
I'm gonna give this option a second thought. Thanks
Click to expand...

My initial thought was NOT having the switch inline with the shift lever, as that could cause engagement prob's. Beside the shift lever would allow rough usage without switch damage too. Also keeping switch inside cabin for better reliability.
If I'm switching a fairly high amp devise, I would rather use a relay for the task.
Can you share your idea as to what you're switching?
:fishing:
 
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
 
The 12v source if for powering a proximity parking radar. Last thing geeks wanna do is scratching the eventually new paint while parking.
Still got to check the device exact consumption but I have pretty beefy switches in stock, rated 0.5A at 125vdc. Hell if it's not enough.
 
Just to be clear, I'm installing 2 proximity sensors, one for the front, one on the back. The rear is already soldered to the backup light 12v source.
 
denpo said:
Just to be clear, I'm installing 2 proximity sensors, one for the front, one on the back. The rear is already soldered to the backup light 12v source.
Click to expand...

U maybe need consider driving lessons????

:crutches::devil::yahoo::goodnight:
 
You can buy special switches for that.
They have a 2 or 3 inch flexible feeler arm that returns to center. The arm looks like the outer sheathing from a manual choke cable.
Common on forklifts, trucks and construction equipment.
You goiung to wire it to apply the brakes like the newer Mercedes?
 
010752 said:
You can buy special switches for that.
They have a 2 or 3 inch flexible feeler arm that returns to center. The arm looks like the outer sheathing from a manual choke cable.
Common on forklifts, trucks and construction equipment.
Click to expand...
Would you have pic of those? I just don't see what it would look like.
010752 said:
You goiung to wire it to apply the brakes like the newer Mercedes?
Click to expand...
Huh???
 
denpo said:
010752 said:
You can buy special switches for that.
They have a 2 or 3 inch flexible feeler arm that returns to center. The arm looks like the outer sheathing from a manual choke cable.
Common on forklifts, trucks and construction equipment.
Click to expand...
Would you have pic of those? I just don't see what it would look like.
I can early next week.

010752 said:
You goiung to wire it to apply the brakes like the newer Mercedes?
Click to expand...
Huh???
Click to expand...

Proximity, get to close, the brakes go on. :quote:
 
Rod75 said:
010752 said:
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
Click to expand...

I see no reason why it couldn't be done to an auto or manual. Both use a lever....:idea:
Click to expand...

Correct.

I've been given an even simpler idea from a CF member : connect the detector to the 12v, and then put the ground on a blade connector on the lever's way. When the connector touch the lever, the lever act as a ground and close the circuit.
 
denpo said:
Rod75 said:
010752 said:
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
Click to expand...

I see no reason why it couldn't be done to an auto or manual. Both use a lever....:idea:
Click to expand...

Correct.

I've been given an even simpler idea from a CF member : connect the detector to the 12v, and then put the ground on a blade connector on the lever's way. When the connector touch the lever, the lever act as a ground and close the circuit.
Click to expand...

Bad practice, electrically, moving parts tend to have grease/oil especially in a car, and therefore that insulates against current flow....the concept is very shakey, failure prone....
 
denpo said:
Rod75 said:
010752 said:
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
Click to expand...

I see no reason why it couldn't be done to an auto or manual. Both use a lever....:idea:
Click to expand...

Correct.

I've been given an even simpler idea from a CF member : connect the detector to the 12v, and then put the ground on a blade connector on the lever's way. When the connector touch the lever, the lever act as a ground and close the circuit.
Click to expand...

The same ground circuit could be run thru a switch as well. I prefer to wire most circuits this way when practical.
You could connect to a solid ground, and let the switch do it's thing. IMO, I wouldn't trust grounding a circuit thru a trans shift lever.
 
Last edited:
Rod75 said:
010752 said:
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
Click to expand...

I see no reason why it couldn't be done to an auto or manual. Both use a lever....:idea:
Click to expand...

Most people drive an auto in "D" so if connected to the shift linkage it would also signal 1st, 2nd and 3rd.
You could just turn it on in the most extreme position, 1st, I just don't see the point. Maybe for tight quarter's parking.
 
010752 said:
Rod75 said:
010752 said:
His thread title says auto.
What good would connecting a switch to any linkage do?
I assume it's an old 350 or 400 and doesn't even have shift solenoids, it's basically hydraulic.
Click to expand...

I see no reason why it couldn't be done to an auto or manual. Both use a lever....:idea:
Click to expand...

Most people drive an auto in "D" so if connected to the shift linkage it would also signal 1st, 2nd and 3rd.
You could just turn it on in the most extreme position, 1st, I just don't see the point. Maybe for tight quarter's parking.
Click to expand...
I might have added that my TH350 has a shift kit, so no more D for me, only 1-2-3.
 
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