retained accessory power quit working?

I'm new here, and by no means an auto electrician, but I know my way around a multimeter, and can diagnose most problems, but not sure where to start with this one. I have never installed an auto alarm in my life, but can read a wiring diagram.

2004 Dodge ram 2500, Clifford Matrix 10 with remote start module added. My truck did not come from the factory with RAP, it is a feature of the alarm. It worked for many years, but suddenly quit one day. After basically shaking the alarm module and harnesses, I got it to work again for about 2 days, but cant get it working anymore. I know which wire is the RAP from the module, it shows it in the manual for the alarm, it looks like its a negative trigger.

Any suggestions how to go about diagnosing this? I have found 3 relays, but I think they are for the starter, I am sure there's got to be another relay somewhere for RAP, but I replaced all three anyway, same issue.

Someone please help out if you can, thanks!

Update, After some looking around, the rap wire from the clifford matrix 10 is broken at a splice that seemed to have a diode in it. I found what I think is the other end, the accessory end - if I ground the accessory end to something, with the key out and the truck off, the radio turns on and the windows are able to roll up and down. Eureka! Or so I thought... Bought a new diode of the same value, replaced it with the stripe facing the same way as the broken one, spliced back together and nothing still. I then tried to see if I could test the RAP output of the matrix with a continuity setting on my VOM, one lead to a chassis ground, the other to the RAP wire, started and stopped the ignition, and it doesn't seem like the RAP wire is supplying a ground. Is it possible the something inside the brain just fried and it's not fixable? Suggestions anyone?

You'll probably want to test for voltage vice continuity. One lead to +12v and the other to the RAP wire. Is the aftermarket RAP a module or a set of relays? If it's a module, what's the brand/model?No question is stupid or not worth asking. You were once a noob, right? :)

I'm not sure what you mean by "voltage vice continuity". Basically, the RAP is simply a wire on the Clifford Matrix 10, that goes into a set of relays. In the wiring diagram, the RAP wire is shown with A (-) sign next to it, I'm assuming that means it's a negative trigger?

rknaub wrote: Eureka! Or so I thought... Bought a new diode of the same value, replaced it with the stripe facing the same way as the broken one, spliced back together and nothing still.

The RAP relay and associated wiring is intact because you grounded the wire, and the accessories came on. I'm not sure why there would be a diode in the trigger wire from the Matrix. Unless it was really a resistor to limit current if there were two relays (I don't know it would be done this way.)You say you installed a diode. The stripe has to be towards the Matrix. If you put it in with stripe facing awayfrom the Matrix, that's the problem. To test the Matrix RAP output, I would use a small light bulb like a #194. Connect one side to 12V+ source, the other side to the Matrix RAP output. Don't forget to close the doors while testing, or the RAP will turn off with key-off. There's some ideas. Diode is backwards, test the outputwith a light bulb

Great idea! Thanks! I tested it as you suggested with a light bulb, and unfortunately it does not come on when I turn the key off (doors are closed). I then grounded the bulb to the spot I grounded the other wires to test the bulb, and it does light up when I do that. Only conclusion I can make is that something is bad inside the Matrix 10 brain. Everything else works fine. So, if I get a replacement unit from eBay (all I can find is the matrix 10.5), can I just swap harnesses to the new unit? Plug and play? Or will it have to be programmed with a bit writer or something?

Well I found a Matrix 10.2 for $70, I liked the remote better than the 10.5 anyway. Added two way arming to my keyfob, yay! Plugged right into the harnesses from my Matrix 10. Everything works great now!! I opened up the broken unit and found the culprit, there's a fried capacitor in line from the RAP connection, I'm sure I can replace that, but I like the two way capability of the 10.2 anyway. Thanks everyone for the suggestions!