2nd starter general knowledge

whats the FUNCTION or reason behind a second starter circuit/relay... I have installed only 3 remote starts so far and haven't NEEDED it so what it is used for? What can it be used for? Is it necessary on some models? I know vague but just trying to soak it all in.

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The RIGHT way is the ONLY way.

Some Nissans have a second starter wire that is there for "fuel enrichment" - necessary for a cold engine start.

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Soldering is fun!

so if the car needs it then only while it is cranking? hence the 2nd starter reference?is it just nissans. is there another use

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The RIGHT way is the ONLY way.

No toyotas have it as well.

Some Toyota's have two Starter wires at the ignition switch.  ( Camry, Avalon, Highlander, RAV4, depends on year. )

Just the way the design engineers decided to do it....

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Soldering is fun!

i appreciate the knowledge guys. dont have one to do right now but i keep seeing people refer to 2nd starter.... gotta wonder why they do what they do. 2nd accesory i kinda get but starter? so its manditory if that vehicle has it, to be used. and it would generally be a necessity not lets say....another convenience function.

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The RIGHT way is the ONLY way.

Well that question is a whole different story, we discussed it on the platforms already, look it up.

If you don't use the second start wire, the car will be difficult to start in cold, will start fine in the warm.......think of it as a choke.

you should always hook up second starter. on nissans it's referred to often as the "cold start wire".

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A DMM is a beautiful thing.

MECP Advanced Installer Certified.

zerepdivad wrote:

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you should always hook up second starter. on nissans it's referred to often as the "cold start wire".

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This was what i thought, but then the guys on this sight informed me that this wire although being present, is not always functional, i'll see if i can locate the thread.

thanks. just trying to gather info for future use. IF an alarm or RS has a second output that is cofigured for 2nd starter and is same polarity as the vehicle...then no relay right just hook up and go? I keep seeing a relay for like toyota etc. is that only if module has primary starter only.

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The RIGHT way is the ONLY way.

Many times the 2nd starter output is a low current (-) output. If so, a relay will be required.

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Kevin Pierson

most units on the market have the following (+) outputs on its primary (larger gauge harness)

start 
ign
acc
parking light
5th relay (can be configurable for acc, ign, or start)
and two 12v (+) inputs.

the toyota requires a relay onlybecause it is a postive start wire, whereas the unit outputs a negative. Therefor you must use a relay to convert the polarity.

if the car has a negative start, as KP mentioned, it is often 250ma up to 500ma depending on brand. You should always rather be safe than sorry, so just wire up a relay even if it is a low current system. If using a relay,  remember to use a diode across the terminals to prevent backfeed on the unit which might damage the output.

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Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert

tedmond wrote:

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If using a relay,  remember to use a diode across the terminals to prevent backfeed on the unit which might damage the output.

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All reputable manufactures include the diode assuming the low current output will drive a relay. I've never seen a unit (even cheap ones) that don't have the diode built in. The typical output section of a remote start / alarm contains a driver chip that has multiple Darlington transistor arrays with all required resistors and diodes built in.

Here is a datasheet for a very common driver chip: https://focus.ti.com/lit/ds/symlink/ulq2004a.pdf and the schematic is on page 3.

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Kevin Pierson

Yes Kevin but for how long it takes to install and its cost I'd rather add one, I blew out an older G4 Clifford once by being lazy.
Also NEVER parallel out to the two starter wires, always adjust your outputs as above or relay it.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

time is not a concern for me. I have a unique experience, because I am firefighter/medic and work at a restoration shop on time off. kinda boutique work. the job takes whatever it takes. i get to solder evrything and heatshrink. BUT it's mostly pre computer stuff. I have been getting more late-model stuff after a couple installs made it around to some shows. so i have to try and catch up with everybody. thanks for the help evrybody

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The RIGHT way is the ONLY way.