2003 expedition, remote start

Installed a crime stopper RS-1804-DPII with the OFA (one for all) bypass on the 2003 Ford Expedition. The remote starting portion is intermittent. Meaning the car will start shut off and start again and stay running. Sometimes it will start and stay running on the first attempt and other time it takes two attempts. I initially thought tach, but it is doing the same thing in both modes(tach and tachless). I did not run a wire to disarm the factory alarm ...will that be the issue? I do not think I could ever find the factory disarm wire.

What you can do is leave the key in the cylinder(do not turn) and try to remote start.  If it remote starts all the time then it may be a bypass issue.  If it gives you the same issue then you should try getting a new tach signal.  The question I would ask too is where did you pick up your tach signal in the first place?

According to customer, when key was in cylinder, the car did not remote start at all. Customer said it remote started, but did not stay running until after second attempt. Two days later, customer says car is not remote starting at all, but lights are on and gets a confirmation that is running on two way. I rechecked all wiring and it was good.

Re-check your tach signal.  Try learning it again.  The wire that should at least be used is white.  It seems like your crimestopper unit is not sensing that the vehicle is and tries to re start again.  I don't deal with crimestopper at all but I would suspect that this is whats causing the remote start failure.

Try to get a different source...i went directly to a injector on a maxima and it still didnt crank right the first time.  I decided to go behind the instrument cluster and got a different wire and worked all the time.