n/o n/c starter kill

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=80706
Printed Date: May 14, 2024 at 3:21 PM

Topic: n/o n/c starter kill

Posted By: jeryl
Subject: n/o n/c starter kill
Date Posted: July 24, 2006 at 8:38 PM

k im looking at the starter interrup relays... it looks like there is a diode... so my q's is do i have to put a diode in a n/o and n/c relay... here is the diagram https://www.the12volt.com/relays/page2.asp

Replies:

Posted By: JWorm
Date Posted: July 24, 2006 at 8:46 PM

In 8 years of installing I have never used a diode on a starter kill relay.

Posted By: jeryl
Date Posted: July 24, 2006 at 9:20 PM

thanks its jus that diagram looked like there was a diode ... i was jus too lazy to hook a up relay to my jump starter to test it... LOL!!!

Posted By: dualsport
Date Posted: July 24, 2006 at 11:21 PM

The diode is only needed if you're controlling the relay with an electronic circuit that's sensitive to the voltage spike that happens when the relay is turned off.
If the circuit isn't designed to handle it, the spike could damage it-
A commercial product should be protected internally, but if you have any doubt about it, you can add the diode across the coil just to be sure.

Posted By: jeryl
Date Posted: July 24, 2006 at 11:37 PM

ok yes i did learn that ur supposed to put the diode to protect against voltage spikes... now my other q's is where would the diode go??? i seen a picture and it shows... its or a bulldog remote starter 500 model starter kill negative output when armed

86-input from alarm -

87a- starter side

85- ignition

30-engine side starter cut in half

another wire goes to the 87a from the alarm

so the diode shows anode to 86 and cathode to 85

its different from the relay shown on www.the12volt.com

is that right connection???

Posted By: dualsport
Date Posted: July 25, 2006 at 12:38 AM

The coil terminals on the relay, 85 and 86 are interchangeable as long as it doesn't have a built in diode. The diagram shown just has it the other way; either way is okay.

The way to connect the diode is to make sure the striped cathode side always goes the the 12V side, so that it's reverse biased when the relay is energized. The diode only conducts when the voltage spike happens, and starts bringing the voltage up beyond 12V. Then the diode starts conducting and limits the voltage.

If you get it backwards it'll definitely blow something, so just make sure it's right.