remote start multiplex with no relays

So I am installing a ct-5072 on a 2001 dodge caravan, in regards to multiplexing for door locks and running lights etc, I was thinking of using the (-) triggers to ground the multiplex signal directly instead of using relays!

I believe most multiplex signals are 5v, for ex the running lights are grounded through a 2.1k resistor.

So I=V/R -> I=5/2100 = .0024A or 2.4ma Which is well below the 500ma that this unit can sink per channel.

Anyone see any problems with this? The manual says to use relays, however i don't see why this wouldn't work? Less parts and easier installation!

https://www.the12volt.com/relays/relaydiagram38.html

The issue with the tech sheet is that they write them so no matter what system you are installing, their diagram will work. The internal resistance on your system will be different than other systems...using relays guarantees that the setup will have the correct values, even if the internal resistance of your system were to change over time. The system would introduce it's own resistance running through the internal components, so you would have to meter the outputs on a bench...then adjust your resistors accordingly but theoretically it should work fine.

For your parking lights you need to isolate from the switch, so you would need a relay.

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Installer, IT support, and FFL. I need less hobbies.

Always use relays for Chrysler multiplex circuits. Using transistorized outputs with resistors inline will work most times, but not every time. If the value is not what the vehicle is looking for, weird things can occur. Trust me. I have done hundreds of Chrysler installs and had to repair many other installs where relays weren't used and had problems. Do things one way - the right way. It doesn't add much time or money and will always work right.

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sparky