CompuStar

I own a 1990 Plymouth Sundance (same as the dodge shadow). One of my friends works at a mercedies dealership and he gave me a free compustar alarm. It is the one with the pager but it dosent have remote start.

I have been looking on the net for about 2 weeks for some install help and the12volt.com was the only help I could get.

I have no idea how alarms work but I do have electrical knowledge. I dont understand what relays do. That is the main problem I have is with relays. If somone could give me some help that would be great. Thanks

no, its not a specific relay problem, its the fact that I dont know what they do. I dont know what their purpose is in alarms..

in my post I said "I dont understand what relays do"

Relays have many applications and are used in a number of ways to supply current to other relays and different electrical devices in a vehicle. Often alarm outputs are negative 12 volts and rated at 200 mA on average and most head units have positive 200 mA outputs. Relay coils can be energized with these outputs and are capable of supplying substantialy more current, typically up to 30 or 40 amps with the ones we most often refer to here. There are some relays used in vehilces that are rated at 200 amps of current and higher. Sometimes relays are used to convert a negative alarm output to a positive output (and positive to negative) to control parking lights, head lights, door locks, trunk release solenoids, etc. or with a head unit that needs to turn on a dozen other components when you turn it on. Sometimes they are used to open a circuit momentarily or close a circuit momentarily. There are simply too many applications to go on listing, but you can find more information on relays here: https://www.the12volt.com/relays/relays.asp

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