alarm problem

I work and have worked on Class A motorhomes for 37 years. I have NEVER seen a Class A motorhome have a System that kills the ignition thru a Keyless entry or Alarm system FROM THE FACTORY. I fail to see how Alarm installers would know or determine it was Factory installed. Some Keyless entry systems HAVE the capability of using the Igntion lock out that is designed into the Keyless or Alarm system. All you have to do is use the relay and cut the ignition wires at the Dash Key Ignition switch. The plain fact is, below 500,000 dollars you will not see a Ignition kill system from the factory. Motorhomes, especially Diesels can have enough problems without adding a KILL system thru the Keyless/Alarm system. It would be a big headache for OEM's to incorporate a Ignition kill system. Doug

I do have a motion alarm that is hardwired and is hanging below the front TV. I also have a hardwired alarm that is fused thru the back two 12V ignition panels below the drivers seat. This alarm is wired to the door and has a key fob and and a little push button and tiny red light on the left side of the dash where you can hardly see it. There is also a little red light on the outside of the coach just aft of the front door and that comes on when the alarm is hot. As I said, when ever the batteries have been disconnected and rehooked, the alarm goes off and is very diddicult to turn off. It also went off one time when a CAT tech left the key on over a couple of days and the batteries died. The wire for the alarm is black with a white stripe and is in a plastic flex conduit with several others
Maybe it is after market, but two different alarm techs have looked at it and said it was installed when the coach was built. Mebbee, it was an option on the 7390 LTC, but I haven't found any on here.

after reading it again, most alarms are programed to send a alarm when the battery's drop blow around 11 volts or so. most will send a battery restoral and light up some sort of trouble code so the tech or occupant knows there was a low battery event

This would be the cause of the alarm going off. The alarm panel probably has some sort of output relay, that is triggered on alarm, that is putting a break in the ignition wire. If you post a picture of the alarm I will see if I can tell you what you have if it was built in the last couple of years. I am assuming that you have a hardwired motion, and the switch just shunts the wiring to ignore the change of state at the motion relay. Some alarms do have a key switch zone that will allow you to turn it off and on with a switch, but they are not very common any more.

most alarms are triggered by a change in the wire leading to the trigger zone going form closed to open. if the door switch is frozen shut, then when you walk into the motion, it will tirgger the alarm.

Do you have any photos of that security system? Doug mentioned it was installed by a previous owner. May be easier to see what they installed to help.

Bigdog wrote:
Ok, here is the follow up. Got a mobile mech out finally and after pulling the new batteries and checking all the connections, we found one wrong connection. Reinstalled the batteries and hooked them up and the alarm went off as soon as that happened. Got in the coach and got the alarm stopped and no igniyion. Tried several things and determined that there was no key recognition between the key and the back. Noticed that the alarm lite was still blinking, so closed the door and opened it and the alarm went off again. Got it turned off and still wouldn't start.The tech asked if the lite went out ever and I said it did.. Pushed the little button next to the dash, the alarm went off and stopped and while I was holding the button in, out of frustration, it chirped several times and the flashing lite went out, the engine started and I was happy. The tech went back under the front and found the wires from the 12V fuse panel and followed them to the alarm box. It was a factory installed system with an ignition lockout.
My rig also has an interior motion alarm above the dash under the TV and when you go to bed, you just flip a switch to arm it. Anyone walking past it will set it off. Never tried it yet.

We sold and I serviced(1994 to 2006) all National motorized until they went out of business. National NEVER installed a Security system that included a Ignition lock out. That ignition lock out system was installed by a previous owner. Doug

Ok, here is the follow up. Got a mobile mech out finally and after pulling the new batteries and checking all the connections, we found one wrong connection. Reinstalled the batteries and hooked them up and the alarm went off as soon as that happened. Got in the coach and got the alarm stopped and no igniyion. Tried several things and determined that there was no key recognition between the key and the back. Noticed that the alarm lite was still blinking, so closed the door and opened it and the alarm went off again. Got it turned off and still wouldn't start.The tech asked if the lite went out ever and I said it did.. Pushed the little button next to the dash, the alarm went off and stopped and while I was holding the button in, out of frustration, it chirped several times and the flashing lite went out, the engine started and I was happy. The tech went back under the front and found the wires from the 12V fuse panel and followed them to the alarm box. It was a factory installed system with an ignition lockout.
My rig also has an interior motion alarm above the dash under the TV and when you go to bed, you just flip a switch to arm it. Anyone walking past it will set it off. Never tried it yet.

Verify your batteries are hooked up correctly. Using your meter verify you have good 12v where you are supposed too.

National NEVER connected the Ignition to a Remote/Alarm system. I am not aware of ANY Class A maker that has an Ignition kill system connected to the Keyless entry. Your system is aftermarket. Doug