petest202 Posted March 7, 2011 Report Share Posted March 7, 2011 hi again. does anyone know a lot about electrics? its a long story. im trying to connect a boot solanoid to my scorpion sa30 alarm. i first connected the negative 200ma output direct to the solanoid.it worked the once. but as it didnt work after that i knew i had done something wrong. ive been told by doing that i have damaged the alarm unit? but im still getting an output when i press the key fob. ive bought a multimeter but not sure if im using it right. if i am, im getting about 4.7v and 1.5ma . could this be right.? the meter dial is set on 20m currant when i test it. i earth it to the car body. as its a10 to 20ms output, its not easy to raed the meter. first i need to know if im using the meter correctly and if so, can increase the currant and/ or voltage enough to work a reed relay or something.? hope someone knows their stuff. cheers pete Link to comment Share on other sites More sharing options...
stevenc1603 Posted March 8, 2011 Report Share Posted March 8, 2011 Normally when wiring in a solenoid you would need to wire it through a relay. This is because the output from the alarm is normally a much lower current than is required to operate the solenoid. You may have overloaded the output of the alarm unit. Hopefully not but I don't know enough to help you check this. Link to comment Share on other sites More sharing options...
petest202 Posted March 8, 2011 Author Report Share Posted March 8, 2011 yea im not sure whats happened to the unit. im not up on circuits but im reading up on electrics now, its bloody confusing lol. the output was supposed to be negative 200ma max. i just thought it would act as the earth for the solanoid. but as i have read, its to do with the 200ma max. as i understand it, the positive charge returns to the battery through the negative alarm output, so technically its a return input. its all too confusing. but i still have something there when i press the boot release button. i have made lots of measurments with my multimeter. just need some genius to work out what it all means. im just hoping with a few resistors or some easy gadget, i can get it to work. otherwise its about £50 for a new unit. not that much i know, but i dont even know if its the way the alarm was set up when it s installed thats causing the problem. i might put a new unit in, and its still the same. please if you know an electrical genius, give me a shout. cheers pete Link to comment Share on other sites More sharing options...
Custom Ice Posted March 9, 2011 Report Share Posted March 9, 2011 Having bee trained to fit alarms i'd say you've 99% killed the trigger output on the unit. As mentioned above a relay should have been used to provide the power to the solenoid, as these pull a rather higher current than 200mA. the fact you now have 1.5mA is either an indication of a dead unit or that you are not reading the merer right. My guess is a dead unit. Alarm fittign and relays also carry additional headaches such as Back EMF, or in laymans terms a ruddy big reverse voltage spike. It's due to the way coils/electromagnets and mechanical components work, and diodes are used to protect the circuits involved. Try the solenoid with direct power and see if it works, if it does you know where the fault is. Link to comment Share on other sites More sharing options...
petest202 Posted March 9, 2011 Author Report Share Posted March 9, 2011 (edited) thanks for that, you know your stuff then. sent you a pm. yea the solanoid still works. i have bought a new unit now,so with a little advice it should be sorted. given up the idea of using the little output i still have from the unit, theres not enough currant to work anything. cheers pete Edited March 9, 2011 by petest202 Link to comment Share on other sites More sharing options...
Custom Ice Posted March 9, 2011 Report Share Posted March 9, 2011 PM read and replied to, hopefully we'll get your boot popping Link to comment Share on other sites More sharing options...
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