I have a 1998 Honda Civic EX Sedan 5-Speed
Installing a Viper 5002 alarm system

Add-ons:
Tilt sensor 507M
Glass break sensor 506T
Backup battery 520T
2 Piezo sirens

I am totally confused as to the using of diodes and relays, or if they are even needed on the above setup?!

Can someone please simplify if they are needed, if so where?

Please do not tell me to have it professionally done, if i had the money I would not be here asking for help.

Thank you in advance.

 

as far as the diodes go i don't think you should need any.

the only relay I can think of that you may need is one for the additional sirens. The output current on the alarm may not be enough to run 3 sirens. So I would recommend doing a relay so that the sirens are as loud as they are capable of being.

go to to website below for a wiring diagram. look at the one for "Connecting Additional Devices to a Remote turn on" and just replace the remote turn on at 86 with the siren output from the alarm. and hook all the sirens to 30.

http://www.the12volt.com/relays/page5.asp#rtol

 

Hi Sigracer10,
So i should run my alarm Brown H1/3 (+) Siren Output to 86 on the relay, then run my 3 sirens to 30?

What would be my fuse amperage on 87 for all 3 sirens?
Should I have fuses on each of the 3 siren connections? If so, what should the amperage be?

As far as the Ground, can it share the ground from another device on the body chassis, or does it need it's own?

Thanks so much Sigracer10!

 

1) yes brown H1/3 to 86 on relay. red wire(+) of sirens to 30. 85 to ground. 87 to +12V constant.

2) a single 5 amp fuse should be sufficient, placed in line with the +12V constant wire, before the relay. it is not necessary to fuse all the individual sirens.

3) my recommendation for the ground would be to ground the alarm, relay and all the sirens at the same spot. If you can find a good clean factory ground bolt that all the wires can easily reach to, then use that. If thats not possible then simply find a good spot of metal that goes straight to chassis and make you own grounding point. Either way should result in a sufficient ground.

 

Fully understood for even a beginner like me. Thanks so much Sigracer10 for taking the time to explain it to me!!

One down and about 100 more confusing issues before I do the install...heheeh

Thanks again Sigracer10!!

-Joseph

 

I used diodes to isolate multiple sensors connected to one input trigger on my alarm installs. I don't know if it is 100% necessary since they were all ground triggered, but I've always done it that way.

As for an alarm, talk about one of the things that is time consuming to do the correct way. I ran a "fake" harness behind the instrument cluster (sorry thieves) and hid my alarm brain in an area that will require disassembly of the vehicle's interior. Even worse, I used what appeared to be factory wiring colors, so I made sure that I triple checked everything in the process of doing the install since my alarm wires are sort of non-standard.

As for relays, my 1997 Civic was the first time in my life that I ever used a relay to provide ground to turn on the dome light. It would NOT turn on with just the alarm wire connected to the dome light trigger in the factory alarm harness. I called one of my installer friends and he reconfirmed that "some" vehicles require a relay to send a ground pulse because the ground pulse from the alarm itself is weak. It worked, but I still can't figure out why one would need a relay to boost the dang ground.

 

to answer this question for you. most alarm domelight outputs are only 200mA outputs. but a domelight needs a ground that can supply the same or more current through the ground that the domelight receives through the positive input. most domelights range anywhere from 3A -10A of current, so the domelight needs a ground that will show a minimum of of the corresponding amount.

by putting in a relay, when triggered, it supplies as much ground as the wires used are capable of giving. which would be over 10A and should be more than enough for the domelight.

the reason it will work sometimes and not others depends on where you tap into the domelight wire. If you tap into it BEFORE the factory relay, then the 200mA ground from the alarm should be enough to trigger the domelight through the factory relay and you would not need your own relay. but if you tap into the wire AFTER the factory relay (in between light and factory relay), then you would have to supply your own relay to allow the domelight the ground current it needs to operate properly.