Some help on Relays/Diodes for Remote Car Starter

[KINGPIN33]

Hi all,

I'm currently installing a remote car starter w/ a door locking feature. Before someone starts to flame me to search, trust me I did! I've searched extensively through the12volts.com, this site, my manual etc. I've seen the car's wiring diagram etc.

For power door lock/unlock, do I need a relay or is it as simple as tapping the unlock and lock wires on the car? The locks are negative (-) triggered 250 mA. The remote starter module outputs 500 mA negative (-) trigger. Since the module outputs 250 mA more, are resistors needed to lower the mA from 500 to 250? Also, to avoid feedback from the circuit are diodes required too?

I am also not sure about the ignition wires. I found out that there are 2 ignition wires on the CB7. My module has 2 outputs for each ignition wire. Is it as simple as tapping those wires too?

I would love to do a DIY since I couldn't find a specific how-to on this site. Most say its relatively easy to do, but its the relays/diodes/resistors I'm not too sure about. I would take it in for someone to do, but then I wouldn't be able to write a DIY

Thanks.

[bruno8747]

which alarm will you be installing? Does you alarm have built in relays? If it does then no problem if not them you might need to use relays. For the door lock though I dont think you need a relay for them.

[cp[mike]]

most aftermarket alarms/starters have internal relays (since... really... itd be stupid if they didnt). you generally dont need a relay, resistor, or diode, just hook the two wires directly to the proper pair. the alarm's internal relay is basically piggybacking off of the back of the lock/unlock button, and really all the relay is is a lock/unlock button, but its controlled electronically instead of having a flesh&blood finger pushing it.

as far as the starter, ive never installed one myself, so i dont know the details, but all they are, again, is just a piggyback unit that simulates somebody turning the key. so whatever wires get connected when u turn the key, the unit will connect together.

[KINGPIN33]

Thanks for the replys.

I've got some cheap remote starter kit called ProStart (Canadian made) equivalent to one of the Bulldog Security ones sold in the US. I believe it has internal relays since the ouputs are almost identical to the Bulldog Security one.
The starter kit wiring diagram

It looks pretty basic. Just confused about the (-)500 mA that this unit pumps out to the door lock/unlock. Is that too much current for the stock relay in the car? The stock one I think recieves only 250 mA from the door switch I think (got that info from this forum).

Thanks.

[cp[mike]]

hmmm... i dont think thats how much current it pumps out, but more of a rating of the current the unit can handle... if thats true, 500 mA is fine.

[Dirty Harry]

hmmm... i dont think thats how much current it pumps out, but more of a rating of the current the unit can handle... if thats true, 500 mA is fine.

^ x2



Understand this and great enlightenment will come upon you.

[cp[mike]]

ahh... all of electronics summarized into a simple circle of equations.

[bruno8747]

^ x2



Understand this and great enlightenment will come upon you.

Ahhhh I can see the confusion coming now, I think only a few on here would know about that.

[KINGPIN33]

I dunno man, the install manual says that the lock and unlock wires are 500 mA negative output which lasts for 7/10 of a second. This seems to make sense since the output would have to trigger the stock relay.

Nice chart with the equations... Not sure how to use it... I'll take a stab at it lol...
If I want to lower the current from 500 mA to 250 mA and "I=V/R" where V would be constant. To decrease "I" (amps), I need to increase the resistance which makes sense... I'm not too sure what the voltage is coming out of the remote starte module unit is... but basically I measure the unit's voltage coming out of the modules lock/unlock ouput (I get V) and then plug it in that formula with 250 mA as "I" to get my resistance in ohms needed to acheive that milli amps... does this make sense or am I talking out of my ass? lol

Thanks.

[bruno8747]

the door lock amperage on the alarm will work fine with the car's door lock thats the same amp that my alarm came with and I have no problems, and I didnt use any relays.

[cp[mike]]

we have a winner! the way you figured out how to use that one equation is how you use the rest... they have all the variations listed, so any time you need to solve for any variable (to figure out resistor ratings, or calculating source voltages, anything really), the method is right there in the circle.

anyhoo our cars are a ground switched system... the outputs you should be using are negative triggers. meaning the car is providing the current, and the switch is connecting the ground side... this alarm unit is providing a ground, thats it. and because its through a mini onboard relay, it can only handle 500mA (again, the current is sourced by the car, not the alarm or relay). the unit is activating the relay internally on its own, the output wires arent powered, they are only providing an alternate ground wire to complete the car's original lock/unlock circuit.

[Dirty Harry]

I dunno man, the install manual says that the lock and unlock wires are 500 mA negative output which lasts for 7/10 of a second. This seems to make sense since the output would have to trigger the stock relay.

Nice chart with the equations... Not sure how to use it... I'll take a stab at it lol...
If I want to lower the current from 500 mA to 250 mA and "I=V/R" where V would be constant. To decrease "I" (amps), I need to increase the resistance which makes sense... I'm not too sure what the voltage is coming out of the starter unit is... but basically i measure the unit's voltage coming out of the door/lock button and then plug it in that formula with 250 mA to get my resistance in ohms needed to acheive that milli amps... does this make sense or am I talking out of my ass? lol

Thanks.

It was a good try. You just need to understand what each of these things mean. Most people would just throw their hands up and say fuck it. Or more commonly, drool on the floor and rock back and forth while making strange moaning noises.

You could say that voltage (E) is forced. The ampere (I) is a measurement of current, or energy flowing, so to speak. As the equation says, E divided by R gets you I. The voltage supplied against the resistance present determines the amperage that will flow. The 500mA rating is meant to be just that, a rating of the maximum safe current handling of the door lock solenoid circuit inside the unit you want to install. If you want to make sure, just measure the voltage supplied by the appropriate wires, measure resistance of the door lock solenoid, calculate and voila, you have your value. If it comes in under 500mA then you're good. If not, then wire it up to a relay instead, and complete the wiring necessary to have the relay energize the solenoid.

[maroonaccord2.2]

The lock/unlock are (-) trigger....you can just t-tap them right to the alarm. You should NOT need diodes for this application, as I never used them on HONDA applications while I was installing alarms.

You t-tap the ignition harness as well, but the acc. lead has to route through the remote start harness.(usually yellow from remote start harness) That way, the remote start module allows the alarm to stay in armed mode even while running.

I installed my own Clifford IG7000 w/remote start years ago, and have had ZERO issues.

[KINGPIN33]

Thanks all for your input... All I have to do now is locate these wires in the car.

[accordztech]

its easy to find. locks are in the drivers kick, remove the lower door sil and the fuse box ares and you will see a black loom with a gray plug comming out of it. that gray plug is your locks, unless someone has been in there and they cut it out.

for your trunk trigger its in the wiring harness that is kinda exposed when you look under the dash. its like a white plastic and inside there is a harness which is green, the trunk trigger is in there i think its like red black or something.
door trigger can be found at the place that site told you or you can just go into the pillar and find it there since it goes up to the dome light.
your ignition wires are right the ignition harness, black yellow is your ignition and i think black white is your starter. depending on your alarm you would have to either cut the starter wire in half if it has starter kill or if its just remote start you would just tap on to it.

the tach wire is in the engine bay by the distribitor and i tink its blue.

the parking lights can either be found in the kick in the loom by where the power locks were going towards the rear or right at the fuse pannel where you can plug in a spade terminal directly into the fuse block.

if your alarm requires you to find the brake switch for shutdwn then you can either go in the kick or go uptop at the brake switch itself.

thats pretty much it, its pretty cake in our cars, do it right the first time, its nice to have either a logic probe or a volt meter to test positive and negitive triggers.