remote start viper 550 thru dei 450t

Hello, I have a Viper 550 (I think 550hf) and want to add the DEI 450t channel expander. I must use the channel 3 output (WHITE/ blue wire) from my 550 to do so.

However activating channel 3 activates the remote start function of the 550. So this would mean every time I want to use a one of 6 channels from the 450t I would be remote starting my car! (Or does the 550 automatically know that the 450t is attached to its WHITE/ blue wire and therefore not start the car? ? ?)How do I deactiavate the remote start function so I can use the 450t as intended. I would like to designate the remote start function as channel 6 for example on the 450t.

I have thought about disconnecting the 6-pin remote start loom going from the 550 to the heavy gauge relay but i'm not sure if this is the way to go or if it would result in no remote-start capability.

Thanks for your help!

Are you sure you are not confusing channel 3 and button 3? The remote start should have its own dedicated button (or combination) and AUX 3 should have it's own dedicated button (or combination).Kevin Pierson

Hi. Yes I'm sure I haven't confused them. My remote has 4 buttons but buttons 3 (until recently) and 4 didn't do anything. Button 1 was arm/disarm, Button 2 was silent mode / boot release, and both buttons 1&2 were remote start. I have now programmed Button 3 to work but it activates remote start. The 550 manual states to the effect of "a momentary input on the WHITE/ blue wire automatically starts stops the engine, as does pressing channel 3 on the remote". So, I still have no clue.

I have never used that part from dei! However if you disconnect the heavy gauge wires you would not be able to r/s the vehicle, neither would the r/s be able to differentiate if the 450t is connected and it sould not r/s, i would like to think you should be able to connect it to to one of the six channels of the expander and be able to function.commit your way to jehovah and he will act in your behalf. psalms 37:5

The "remote start activation" and the "aux 3 output" should be two separate wires, possibly on two separate harnesses. It's been years since I've seen a 550 but it seems like the remote start activation was in a smaller harness and the Aux 3 output was in the main harness.Kevin Pierson

I would like to think I could connect the r/s to one of the 6 outputs of the 450t as well...but at this stage it doesn't look possible. The harness, among its positive outputs has 3 negative outputs going from the 550 to starter/ignition/and accessories? on the heavy gauge relay...maybe I can disconnect these outputs coming out of the 550 and connect these all up to one of the negative output channels of the 450t? ? ? But I don't know if these outputs are all instant or timed ones.

Yes the r/s is from a secondary harness coming from the 550 to the heavy gauge starting relay (as I just said above)...but there is no separate activation / distinction from the WHITE/ blue wire (channel 3 aux output) on the primary harness. When I activation channel 3 via the fob it starts the car, as well as putting a negative output from the WHITE/ blue wire as measured via multi-meter (funny thing is this wire appears to give a constant positive output when nothing is activated).

I tried emailing DEI directly but as I expected they haven't replied.

The manual never said you have to use the WHITE/ blue wire, it says you must use a wire that provides an instant signal, so i'm sure you have other auxillary channels open that can provide an instant signal,commit your way to jehovah and he will act in your behalf. psalms 37:5

Well there's no other option because channel 2 is not instant output...it is for silent arm/disarm, then boot release when pressed for longer. And channel 1 is arm/disarm. There aren't any other outputs :)

What spare wires do you have on the unit?commit your way to jehovah and he will act in your behalf. psalms 37:5

There's at least one spare wires that give negative output from the remote start secondary harness, however this does not solve the problem of the r/s activating each time I activate ch 3. I have now thought of an idea...I use relay to open a circuit on a safety input such as handbrake switch...so r/s does not activate. While the circuit is open I can use ch 2/3/4/5 without the car starting. I wire this relay to the latched channel 6 of the 450t. So if I want to activate the r/s I activate channel 6 (hit ch 3 on fob 6 times), then hit the fob once more because the circuit would be now closed.Then once car is started I activate ch 6 to unlatch the relay. What are the drawbacks (besides not being able to use ch 1 all the time and having to "reset" my r/s on ch 6)?