Need electrical advice

[NuclearN8]

Has anyone figured out how to have the headlights turn on automatically, if the wipers are turned on, with the headlights in the "auto" position.

My wife has a 2007 and she leaves the headlights on auto, which is fine if it's not raining... PA law requires headlights if the wipers are on (regardless time of day) so I'm trying to modify the circuit so it happens automatically.

Its a limited.

Thanks for all the helpful guidance and thoughts of this is possible.
Nate

 

[BlackWorksInc]

Uhm.... I mean I guess you could? It'd require some wiring to bypass the switches and hopefully not cause odd problems?

 

[NuclearN8]

Uhm.... I mean I guess you could? It'd require some wiring to bypass the switches and hopefully not cause odd problems?

Thanks, I'm simply trying to create a rain-sensing headlights function I guess now that I think about it (so long as the headlight dial is in the "auto" position I want them to turn on if the driver turns on the wipers).

Any ideas on what electrical components I would need to achieve this? A relay or two and two way switch? I'm not as comfortable with electrical items as I am mechanical... calling [MENTION=15785]J.A.[/MENTION] you think this is possible?

 

[Asmara]

Thanks, I'm simply trying to create a rain-sensing headlights function I guess now that I think about it (so long as the headlight dial is in the "auto" position I want them to turn on if the driver turns on the wipers).

Any ideas on what electrical components I would need to achieve this? A relay or two and two way switch? I'm not as comfortable with electrical items as I am mechanical... calling [MENTION=15785]J.A.[/MENTION] you think this is possible?

I've thought about it but haven't had the time to puzzle it out.

What I would do is somehow tie turning the wipers on to to the sensor in the windshield that measures the light. The sensor, probably, just increases( or decreases) resistance which tells the system when to turn on the lights. It wouldn't be difficult to tie something into that circuit that changes the resistance appropriately when the wipers are turned on.

If you work on it, post up your results. I've been thinking about modifying the sensor resistance anyway so that the lights come on sooner.

My SIG has info on automatic headlights that might help as a starting point.

 

[A/V1]

There are others like this, but I think this will do the trick...

Hella Raintronic 87317 Wiper Control With Sensor

 

[Martinjmpr]

On the limited with the "auto" setting, do the lights go off automatically if you accidentally leave them on? On both my 3rd gen and 4th gen SR-5 models, they would do this. I think it was 2 minutes after the ignition was turned off, the lights go off automatically, or if you click the "lock" button twice, the lights go off, even if the switch is still in the "on" position.

If this is the case with her limited, the answer is simple: Turn the lights to the "on" position (not "auto") and just leave them on, all the time.

 

[having fun]

/\ So in doing it this way, she will have the wipers going all the time.

 

[iBison]

Couldn't you just run a line from the power going to the wiper motor to the power in on the headlight relay and add a couple of diodes. Similar to what's done in the diagram below.

 

[snowboardwcu]

i live in PA and have never heard of this rule. where are you that you're worried about this? jc

this shouldn't be too difficult unless you want it to work with the intermittent wipers as well.

i imagine the wiper circuitry is constant power to the wiper motors when on (against, not intermittent). pull off that and into the light relay(s) you want activated. use diodes (as an electrical check valve for the mechanically inclined ) to prevent back powering both circuits when either is on. depending on the draw of the lights (10 amp fuses, right?) you may need beefy diodes or that might throw a wrench in my thought completely. not sure.

if power is not constant to the motors, then you will need to determine a way to sense when the wiper switch is activated and proceed similarly.

 

[snowboardwcu]

Couldn't you just run a line from the power going to the wiper motor to the power in on the headlight relay and add a couple of diodes. Similar to what's done in the diagram below.

provided a diagram quicker than i could type what was in my head. :yo:

 

[iBison]

provided a diagram quicker than i could type what was in my head. :yo:

Good point about the intermittent wipers, that may be hard to get around. I don't have an immediate solution. She could just leave the lights on all the time.

We have the same law in Illinois, lights have to be on when wipers are required.

 

[snowboardwcu]

TECHNICALLY the lights would be on while the wipers run. But that isn't the point of the law and imo is much more distracting.

There must be one.to.many signals from the wiper switch to the ECU/some computer. I imagine that would work.

How many amps do the headlights draw? I do see most people using the 3A diodes for smaller lights.

 

[DarenS]

Has anyone figured out how to have the headlights turn on automatically, if the wipers are turned on, with the headlights in the "auto" position.

I trained myself to automatically turn on my headlights when I turn on the wipers, but that's probably not the answer you're looking for.