fusing a relay

You don't need to fuse the coil per se - it would only be if you wanted to protect the +12V source, or the wire from it to the coil's #86.

If the factory arm/disarm was neg based, you wouldn't need a relay, since all the R/S outputs for this function from every alarm manufacturer are neg. Even so not more than 2amps in this case.

howie ll wrote: If the factory arm/disarm was neg based, you wouldn't need a relay, since all the R/S outputs for this function from every alarm manufacturer are neg. Even so not more than 2amps in this case.

really? In the manual for the 4113 install it says to use the (-200 ma factory disarm output) hooked up to a relay even if its a negative triggered system?

Sorry, mini relay, 2amps max or even a transistor trigger, Oldspark can probably give you a circuit. Also you will find they are WRONG. Most factory disarms draw about 120milliamps. But if it makes you feel better use a pcb/mini relay, eg DEI 8616.

Of course it would help if you would tell us what vehicle?

howie ll wrote: Of course it would help if you would tell us what vehicle?

08 ford fusion.. thanks for everything howiee

OK, I've looked at the instructions and I STILL can't see why they need a relay! Except for polarity change which isn't necessary on your vehicle, it's a PURPLE / something and it's neg. However sort of calling them and asking their reasons, I'll take their word...except on the directwire vehicle specific installation guide, it isn't mentioned at all, the point here is that the Avital's neg alarm disable wire would carry the same current rating as say a Viper 5902; in fact the rating would be the same on ALL DEI product,why isn't this mentioned on say Python or Viper or Clifford install guides, don't tell me I've caught yet another DEI typo.

Just went back to the 5901, that lists those relays so I apologise! 8166 mini relays with a 2 amp fuse.

so the -200 ma output wint be enought to trigger the disarm wire? :/