Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS
Sponsored by:
Sponsored by: DashLynx

How to apply 12V To a Relay?

Thread Tools
 
Search this Thread
 
Old 03-07-2013, 11:02 AM
  #1  
Registered User
Thread Starter
 
Gamefreakgc's Avatar
 
Join Date: Sep 2012
Location: Roseville, CA
Posts: 1,172
Likes: 0
Received 1 Like on 1 Post
Question How to apply 12V To a Relay?

I'm looking to diagnose why my lights-on reminder and "door courtesy switch" don't work anymore. Tired of killing my battery because I can't tell if my headlights are on. According to the FSM, I need to apply battery voltage over the relay:

Lights–On Warning System
1. INSPECT DOOR COURTESY SWITCH
See combination meter on page BE–39.
2. INSPECT LIGHT REMAINDER RELAY
(Relay Circuit/Operation)
(a) Connect the positive (+) lead from the battery to
terminal 3 and the negative (–) lead to terminal 4.
(b) Check that the buzzer does not sound when con–
nected terminal 1 or 2 to the positive (+) lead.
(c) Check that the buzzer sounds when disconnecting
terminal 1 or 2 from the positive (+) lead.
If operation is not as specified, replace the relay.

What's the best way to do this? I have a multimeter but it only puts out up to 9V so I don't think it will work. I don't have any spare wires around... is there a cheap trick or tool I can pick up that will do the job? Electrical is not my specialty
Old 03-07-2013, 12:49 PM
  #2  
Registered User
 
scope103's Avatar
 
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes on 649 Posts
In the time it took you to type this, you could have driven to the hardware store and picked up a spool of wire.

What you want is something like these: http://www.harborfreight.com/36-inch...ads-66712.html . The clips mean you can do it with only two hands. These are 18ga which is much bigger than you need for a relay (24ga is good enough for the current, but a little mechanically flimsy for auto work). The 18ga, though, will be good enough if you want to test a 35W headlamp with them. (

Or, just about any wire will do for a relay. Yes, you could even unplug the leads from the multimeter and use them. Wire is wire. But do yourself a favor and pick up some "test leads."
Old 03-07-2013, 01:03 PM
  #3  
Registered User
 
stanprophet's Avatar
 
Join Date: Feb 2013
Location: Hampton VA
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Nearly any automotive store will have a set of test leads in the electrical section. Also you can buy a pack of test leads from any radio shack.
Old 03-07-2013, 01:09 PM
  #4  
Registered User
Thread Starter
 
Gamefreakgc's Avatar
 
Join Date: Sep 2012
Location: Roseville, CA
Posts: 1,172
Likes: 0
Received 1 Like on 1 Post
There's a Harbor Freight within walking distance of where I live so yeah, probably! I just don't like the idea of shocking myself... again...

The clamp one will do the trick for me. It's only yours truly working on the truck so I can't rely on an extra pair of hands. Thanks for the help.
Old 03-07-2013, 04:12 PM
  #5  
Registered User
 
scope103's Avatar
 
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes on 649 Posts
Originally Posted by Gamefreakgc
... I just don't like the idea of shocking myself... again...
Don't worry about 12v; you can't feel that, even with wet hands.

The only thing on a truck that can shock you is the spark-side of the ignition system (coil - distributor - plugs). The voltage is plenty high, but the current is low. It will really smart (so don't do it!), but the current is low enough that you'll survive. Probably.

Last edited by scope103; 03-07-2013 at 04:13 PM.
Old 03-07-2013, 04:55 PM
  #6  
Registered User
 
ThatGuy1295's Avatar
 
Join Date: Jan 2011
Location: 46 50' 36.82'' N 122 19' 41.01'' W
Posts: 1,746
Likes: 0
Received 6 Likes on 5 Posts
shocked he say's

I dont know about you, but I always wear rubber gloves and a cup when using jumper cables. And im sure never to actually touch the jumper cables. I dont want to get electrocuted.

And I always take the battery completely out of my truck and make sure its atleast 80 feet from the vehicle when changing my headlight bulbs, I dont want to end up one of those statistics.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ashamsuddin
General Vehicle Related Topics (Non Year Related)
17
01-13-2023 03:17 AM
bradahman
86-95 Trucks & 4Runners
8
10-01-2015 09:24 AM
beltcutter
Newbie Tech Section
1
09-30-2015 06:14 AM
JPV
Pre 84 Trucks
2
09-28-2015 03:15 PM
Rcbc92
95.5-2004 Tacomas & 96-2002 4Runners
5
09-26-2015 03:00 PM



Quick Reply: How to apply 12V To a Relay?



All times are GMT -8. The time now is 02:33 PM.