I have a model ms8300 ungo pro security system in a moterhome and has been in storage for 12 years now when I power up the alarm it triggers and will not stop alarming can someone help me with this problem????

SOURCE: Disarm car alarm

first off ill assume the alarm goes off and oviously you have no remote. first disconnect the negative ground (black wire on your battery) so you can work with out the alarm going off.

the "brain" of the alarm should be located on the drivers side underneath the dash, go underneath and look for a small black box zip tied into place with wirescoming into it that looks like it shouldnt be there. it should have crimestoppers inscribbed into it.
there will be wires clipped into the brain, disconnect these and your alarm is deactivated.
to remove, trace wires to where they tie in, cut off wire that leads to brain leaving origonal facory vehicle wire there, and tape over cause you dont want anything to ground out. once you have done this, reconnect the negative, and your good to go

SOURCE: alarm going off

When you arm the alarm, hit the lock button twice within 5 to 10 seconds. If it does not go off any more it is the interrior sensor.

SOURCE: Clarion ungo alarm model 5100

Can't seem to locate a manual. Just get into the wiring under the dash and follow the larger wires from the alarm brain and cut each wire, one at a time, from the factory ignition harness them tape. Start with just the starter wire to see if that fixes the issue for now. If this problem just started, check to see if there is a tach wire that runs under the hood to a coil or injector. If this wire is disconnected the remote start won't see the car is started and will continue to crank the starter.

SOURCE: I need a car alarm manual in English for a LONG-E

http://static.zoovy.com/merchant/gooddeals18/le6500pdf.pdf

SOURCE: disable viper alarm

Yes the best way is disarm the alarm and put in a Valet Mode
To activate the Valet Mode do the following:

There is a push button or toggle switch to disable the alarm (to engage the valet mode). Without knowing where this
switch is you won't be able to disconnect the alarm.

1. Put the key in the ignition and turn it to the "on" position.
2. Flip the toggle or hold the push button for at least 5 seconds.
3. The LED. light will stay solid on.
4. Turn the ignition off
5. Release the push button. If you have a toggle leave it alone in step 2