improved gem trigger and wait to start

I'm a novice installing an alarm and remote start on my 2002 Ford diesel and think I've found a much better installation for these items.  I found a lot of great info here and want to share what I found.

On the wait to start, everyone recommends using a 528 timer since the 2002 and up series are computer controlled.  With an engineering background, I wanted a better system and think I've found it. There is a glow plug relay on top of the engine so I took a wire from the energized side of the relay and fed it to the "wait to start" input on my remote starter.  That way I have a true signal for the wait to start instead of guessing with a timer.  The glow plug relay is a positive and the input on the remote starter is negative, so I sent the signal thru a relay to reverse the signal.  I also put a fuse and diode at the wire off the glow plug relay.  The fuse is because the engine really vibrates alot and if the wire chafes in the future at least the fuse will prevent a meltdown of the system.  The diode is just because I don't know if I need to isolate the remote from the glow plug relay.  So from the glow plug relay, I have a 10 amp fuse, then a diode with signal from the relay to the remote starter, then a "regular" relay inside the cab to reverse the polarity, and the input to the remote starter. It works perfect!  If someone sees a problem with this system please let me know otherwise I hope it helps.

On the Gem wakeup, I learned here that you need a positive pulse to wake the system.  On my alarm, the unlock sequence is chirp, parking lights flash, and then the unlock signal.  So I took a wire off the parking light flash and tied it to the driver door latch or trigger to wakeup the GEM and it works perfect too.  I used 2 diodes to isolate the door trigger and the parking light signal on the alarm, again because I didn't know if feedback would cause a problem.  Because of the diodes, it was easier to take off the door panel and make the connections inside the door. 

Thanks for everything you do on this website and I hope these items help someone else.

Nothing wrong with what you did, back in the day, Clifford product had either a neg or pos input directly from the glow-plug indicator. Not that easy with the data powered dashes on many modern vehicles including yours. Having said that it's simpler to programme most good quality remote starts to diesel  and programme in a remote start diesel delay. On a Focus diesel in our (UK) climate I pegged the delay at 4 secs. and it never failed.

Ref the GEM box. Dome light supervision connected to the driver's door contact if wired correctly "tells" the GEM box that the driver's door has opened so I never had that problem. In truth there's often more than one answer to a problem and if it works for you, great and thanks for the info; trouble is there are plenty of novices on this site who I frankly wouldn't trust to safely wire up/install a relay under the hood. ALL my under hood cables are sealed in plastic tubing cable wrap, lithium grease or water repellant is sprayed on hood switch and siren bolts, the rubber entry grommetts are RTV'd and then sprayed with lithium grease, any relays are mounted with the terminals down (for gravity assist and moisture exclusion), everything fused within 4" of source.  Heck, we have to shout at some to fuse or gromett!

It turns out neither idea worked very well and now I'm doing it like everyone else.  The glow plug connection works but the glow plugs stay on much longer than the wait to start light so now I'm putting a timer in.  On the GEM wakeup, weird things started happening like the door open signal was always on, even with the enging running and doors closed.  The signal from the door switch didn't like the diodes or any kind of connection to it so I just spliced that wire together without any other connection to it. 

The other wierd thing now is that the GEM goes to sleep if I use the factory fob to lock the doors but it stays awake if I use the alarm fob to lock the doors.  So the alarm fob will always unlock too.  Does anyone know if the GEM will drain the battery by staying awake?