avital 5303l no remote start wanted

I have a Avital 5303 to be installed in a '06 Sprinter 3500. After researching the installation I am unclear on a few items. I do not plan on using the remote start, only the alarm will be wired. I do have 556uw bypass module. Here are my questions... If I am not using the remote start function, do I need the wire the bypass module? Will the alarm system integrate with the system immobilizer in the Sprinter without the bypass- can I arm / disarm on either the Avital or the factory keyfob remote? Will the doorlocks work using either the Avital or factory remote? Thanks.

You won't need either the 556U or the factory remote to lock the doors. You will need a 451L and a second relay, here's why. Under the right hand seat on UK spec., i.e. driver's side are a cluster of relays. You need motor wire access hence the 451l to lock and unlock the front doors. A second relay then unlocks the side and back doors.

US version, AKA Dodge Sprinter is slightly different, above refers to LEFT HAND seat. Lock all 5 wire blue/red, CTM* pink plug pin 2. Unlock driver's door, BLACK/ red diito pin 3. Unlock passenger and cargo doors , BLACK/ red CTM* grey, pin 17. Door triggers from memory, pull the dome light in the front, BROWN / white (-), front, there's an adjacent loom above that light, has another BROWN / white, test but this should be the side/rear door triggers. Ignition, lights, etc drop steering wheel cowling or pop instrument binnacle, you can also get the alarm brain and the antenna in there. About the easiest vehicle going! *CTM = central timer module.

Ok, I don't know what the 451l is but I think this is the same? http://www.remotestartexperts.com/dei-451m-doorlock-relay-module.html Also, will I still be able to use the factory keyfob for lock / unlock (WAF)? Thank you all!

Yes but the factory fob won't control the 5301.

How about the 5303?

Sorry, I meant 5303.

No bypass is needed. You will probably have to hook up ignition wire on the heavy gauge harness for programming and such. Any other questions?