dawg

Several years ago I had a Viper 100ESP Keyless Entry System installed in my 1990 300ZX at the beginning of the summer. It works great, with one problem.
Once winter came, if the car sits overnight and the temps are around 35 degrees F or lower, then when I use the key fob to unlock the doors (so far so good) once I actually open either the driver side or passenger side door, the factory alarm will go off. What I have to do then, is to put the car key in the door lock and turn it...this stops the car alarm. Remember, this only happens if the outside temps are around 35 degrees or lower and the car has not been used for a number of hours, no other time.
I sent the unit back to Viper to be checked and it checked out just fine. I tried to check all the connections, under the dash (not an easy thing to do) and they seemed tight.
I took the door panel of, thinking that maybe the mechanical servos that were installed to lock and unlock the door were not fully opening the lock, thus not sending the unlock signal to the alarm...but everything was working right.
The auto place that I bought the unit went out of business about 6 months after they installed it so there is no one to go back to.
Somehow the unlock signal to the factory alarm is not being sent when I unlock the car with the key fob, but only on cold days????
Any ideas???

godzilla1978

could be a loose wire where they connected the viper to the car. That's assumeing they used the arm and disarm wires as opposed to the lock and unlock wires. I recommend you take it in to a certified installer and have him/her check it out

dawg

Thanks, however I figured it out with the help of a friend.
The Viper only sends a 250ma signal to the disarm wire that tells the factory alarm to disarm when the door locks are open remotely. In very cold days, apparently the m-amps dropped to a level to low for the factory disarm to work. We installed a relay and re-routed the Viper disarm and the factory disarm wires so that a much stronger signal will be sent. So far...it appears to be working...will know more when it really gets cold.
Thanks for the post anyway.

SheHateMe

The first thing that came to mind with what you described was that there wasn't enough amps getting to disarm it. Do you have an old or weak battery in it? You most likely already solved the problem, but I know that when my old battery couldn't take it anymore, it started setting my alarm off randomly at night when it got to cold and dead.

dawg

No, my battery is new. Besides, the alarm never went off randomly even when my battery was old and low...it would only go off "after" I had unlocked the car with the keyfob and then tried to open the door. Once the door was opened, the alarm would sound off. What apparently is happening is that the Viper unit wasn't sending enough milliamps to the disarm function of the factory alarm to satisfy its requirements, so even though the Viper unlocked the doors, the factory alarm still thought it was an unauthorized entry. This only happened on cold days. Hopefully with the addition of the relay, that problem is solved. Time and a few cold days will tell.

selective sound

iTrader: (11)

The relay will take care of the issue, you are 100% correct.

dawg

Thanks for the vote of confidence...So far the fix has worked flawlessly.
Guess I don't understand why that relay is not part of the normal installation?
Certainly, I can't be the only one that has ever experienced this phenomenon of a drop in milliamps sent to the disarm during cold weather?

Sikk Nation

iTrader: (1)

not so much a drop in milliamps but drop in voltage from the cold/old battery. Also happens alot after a few months when connections are not soldered. Glad you got it solved.