CenCom door ajar programming?!?

[MadMike84]

I have a Cencom sapphire unit with a legacy WeCan lightbar installed. This comes with an option to turn the lightbar off when the driver opens the door. There is a door ajar signal wire on the factory harness (gr/violet). This wire has 10v coming off of it when the door is open and 0v when it is closed. I used the input 1 (+/-) to hook this wire up. But it does not work. Has anyone used this option yet?!? Thanks for any help.

Best regards

 

[buddek09]

I have not used the door ajar but in the Sapphire software, did you make sure, on that input setting, to go into the lightbar configuration and select the modules you want to shut off and set the flash pattern for those modules to off?

 

[MadMike84]

Sure did! Thanks for replying!

 

[SafetyLighting]

You selected the input to be positive right?

 

[MadMike84]

I've tried it both ways. Positive input it doesn't work at all. Yesterday when I was messing around with it it was working but it was backwards. Door open lights are on door closed lights are off. I've got it set to turn off the corner lights so if the officer needs to draw his weapon the lights are not in his eyes. Forgot to mention this.

 

[MadMike84]

Ground electrical connection is when it does work but backwards.

 

[SafetyLighting]

Whelen is very particular with signal requirements. The input has to see an actual 12 volts or clean 0 volts.

 

[MadMike84]

Ok thanks. I'm still confused as to why it's backwards. Maybe I can tweak something in the software? It is working perfect other than it being the wrong orientation for the door. Is there anyway to change this using a relay?

 

[SafetyLighting]

It's backwards because you are supposed to be using the positive setting not the ground setting. You could use it with a relay I think.

 

[MadMike84]

I'll try it on positive again , but I couldn't get it to work at all last time I tried it. I'll post back with what happens. I can upload the .csw file If anyone is interested in see what I have so far. Thanks for the replies!

 

[buddek09]

Sorry Mike, I don't always check this site on the weekends. I don't think it will work just hooking it directly into the Sapphire. As discussed I think you need to use a relay. I think your programming is correct but as pointed out above the voltage isn't enough to trigger it. The upfitter's guide states "the door ajar circuit is used to supply a module that has pull up resistors in it's inputs". Basically means they intend for you to use a device that converts the 10v signal to the full 12v. I tried searching for the module, which they don't have any parts number reference to, and could not find anyone that makes a module. Probably some Ford proprietary module. Basically you would have to design and build your own, though not hard, it's easier to just use a relay. For the relay pin86 to the door ajar signal wire, pin 85 to ground, pin 30 to input 1, and pin 87 to a 12v input or you could just tie it to ground and change the setting for the input to ground. Wiring the relay up this way should make it work exactly how you want it.

 

[MadMike84]

Sweet. Thanks for your time and the advice. I will try it on the one we're building now. The other two already went out. I will post back in about a week or so with the results.

 

[MadMike84]

No go. Relay didn't work. Hooked it up acouple different ways but nothing.

 

[buddek09]

The only option left is to build a pull-up resistor circuit. It's really simple though. You will need a 1k 1/2 watt resistor. Tie one end of the resistor to a power source and the other in parallel with the door ajar signal wire and input 1 with the input switched high. I've attached a picture what I'm talking about. The circuit will give you 12V when the door is open and ground when closed. The resistor prevents the 12V source from shorting directly to ground.

 

[MadMike84]

Ok thanks man!