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relay question - make sense?

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=33452
Printed Date: August 25, 2025 at 12:08 PM


Topic: relay question - make sense?

Posted By: jpdub
Subject: relay question - make sense?
Date Posted: June 07, 2004 at 10:55 AM

Installing a video seyup and don't want to leverage the cars wiring harness. 

So, using a fuse tap from an ACC source to a relay.  The idea is to create my own ACC source w/o too much strain on the cars wiring.  When the key turns on it will power up the relay and I will use this as the ACC power for my dvd/fm modulator/av unit/ relay2.  I could make it easier and bypass the relay, but I don't know if I'll end up blowing circuits....

Fuse box ACC source -> Relay -> DVD\modulator\av unit\relay2

Running a seperate 10 gauge wire from battery.  Prior to the relay this will be the main power for the units above.  After the relay it will be the ACC source.

Relay 2 will be switched on to allow power to my inverter for xbox.  I have a seperate 8 gauge wire from battery which will go through this relay and straight to the inverter.  Problem is trying to get 8 gauge wire connected to a little relay!

Does this all make sense?  Is there an easier way? 




Replies:

Posted By: jpdub
Date Posted: June 07, 2004 at 11:00 AM
BTW - picked up a couple 30amp, 12v relays from radio shack.  Not sure which ones I have,  but do I need SPDT or SPST?  If it's not marked, just 4 connections - 85, 86, 87, 30/51




Posted By: CHaseHeadrick
Date Posted: June 08, 2004 at 10:46 PM
sounds like you have spst (single pole, single throw), which would work fine in your application. a spdt (single pole, double throw) is more usefull if you want to run two things with one switch, ie: one thing turns on or off with the switch on, while another thing turns on or off with the switch off. See? Sounds like you only want to turn on with the ACC (switch) so a spst relay will turn on and off with the ACC switch. connect the wire from your fuse tap to 85, ground to 86, 10awg to 87 or 30, then the DVD, etc. to the other leg (30 or 87). I don't know why you would need the other relay for the inverter, as you could just get a fuse block and run it off the 10awg? If it draws too much current, then just wire up the other relay the same as for the DVD. any help?

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93 4RUnner
Alpine H/U
Alpine Mids/Highs
Alpine Security w/DEI remote
start and window control
Rockford Lows.




Posted By: Teamrf
Date Posted: June 09, 2004 at 6:32 PM
Relays are great now that I understand how they work.posted_image

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~The Rookie~
Rookie of the year that is...
Don't let the smoke out of your equiptment..it doesn't go back in.





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