AUX switches- behavior inconsistent

Akbill

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I connected the Amazon Alexa auto device to pink/orange aux wire under right dash (auxiliary #3) and I a CB radio to the blu/pink wire (auxiliary #4). both set to ignition. #4 only has power when physical switch #4 light is on. #3 has power with it’s switch light, on but also with it off! So #3 switch has a problem- always on.

why is this? defective switch? other?
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vavaroutsos

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The switches don't actually switch the power. They are soft switches. They talk over the CAN bus to the power control module (for factory aux), or the relay module by the brake booster (for dealer installed aux). So my guess is it could be a bad relay since the light on the switch goes off and the other aux switch works properly. This would indicate both switch side and power side CAN modules are working.
 
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Akbill

Akbill

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Thanks. I tested the relay by switching K20 with K21. Aux 3 still stays powered regardless of switch on/off as long as car is on. Aux for still works normally.
I have tried changing the setting to battery, and the switch still doesn’t work. And changing it back to ignition and it still doesn’t work.
The switch doesn’t seem to be getting the CANBUS to do what it should.
Note that switches 1 and 2 are not being used.
note Also, I have a tazer mini in place.

any other ideas?
 

vavaroutsos

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Do you have a DVM? If so, check the voltage on the control coil of the relay for aux3. Let's find out if the control circuit in the power control module is working, or something else is going on with the connections to the relay for aux3. If the relay coil always has power regardless of the aux3 switch light, then I would disconnect both batteries and check for shorts. This would indicate a problem in the power control module. If the coil voltage turns on/off with the aux3 switch, then the problem is not in the control side. This would indicate the problem is in the power side, maybe power is shorted to the aux3 relay output contact or something.
 
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Akbill

Akbill

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Wow, ok. Thankyou. sure I have a good DVM, but dont know how to test the K20 relay, Where would I connect the multi meter probes? Remove the relay and test for positive and one of the K20 terminals in the fuse block?
I did that test and both of the Kay 20 terminals that are closest to the bumper have power 12 V with the car on or off. I then turn on the car with the relay removed and it made no difference. So I then removed the fuse F103 and it still made no difference, which tells me that like an idiot, I have to be connected to the wrong wire. I will explore that next. My wife helped me identify the wire colors, as I am colorblind more or less. I think she mixed up #3 pink/orange with ignition orange/pink, you got to admit it’s pretty confusing looking at those tiny colors under the dash.

Do you have a DVM? If so, check the voltage on the control coil of the relay for aux3. Let's find out if the control circuit in the power control module is working, or something else is going on with the connections to the relay for aux3. If the relay coil always has power regardless of the aux3 switch light, then I would disconnect both batteries and check for shorts. This would indicate a problem in the power control module. If the coil voltage turns on/off with the aux3 switch, then the problem is not in the control side. This would indicate the problem is in the power side, maybe power is shorted to the aux3 relay output contact or something.
 
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melendez69

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Thanks. I tested the relay by switching K20 with K21. Aux 3 still stays powered regardless of switch on/off as long as car is on. Aux for still works normally.
I have tried changing the setting to battery, and the switch still doesn’t work. And changing it back to ignition and it still doesn’t work.
The switch doesn’t seem to be getting the CANBUS to do what it should.
Note that switches 1 and 2 are not being used.
note Also, I have a tazer mini in place.

any other ideas?
Did you ask Alexa?

*sorry...couldn't resist.
 
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