checking relays

Jay633 · 12-28-2011, 07:36 AM

Im sorry I tried looking but didn't get much info. Can I put a wire on the spades and turn the ignition switch to on then put the tester on the wires and see if there's power in all spades?

cre · 12-28-2011, 08:48 AM

It depends on the relay but the basic functionality is generally the same... You just need to figure out which pin is which. I found this cool picture sometime back that I've been saving... Just waiting for the day that I could actually point to a graphic when I say: 85 and 86 are the coil; 30 is the constant (power supply or ground); 87a is the "Normally Closed" and 87 is the "Normally Open". When power is applied across the coil the generated magnetic field throws the switch inside opening the circuit between 30 and 87a and closing the circuit between 30 and 87. This is what's generally known as a "Bosch" type relay.

So look at the TEWD and figure out which pins are the coil and which are the switch. Measure across the switch when the coil is powered and when it's not. Which relay is it?

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Jay633 · 12-28-2011, 05:18 PM

The relays I want to check are the efi relay.l Fog light relay. And the circuit opening relay even though im having trouble find that one

cre · 12-29-2011, 01:07 AM

Look in the TEWD, it shows which pins are the coil. Test the coil to make sure it's not broken (if you use the conductivity test setting, the one that beeps, it should beep). Then put the leads on the other two pins (the switch) and touch the coil leads with a 9 volt battery or another voltage source up to 12v. When the coil has power, the meter should beep indicating that the switch is good. That's as much as I can simplify the process, it's really easy but having a set of test leads with alligator clips and not the straight probes REALLY helps.

cre · 12-29-2011, 01:12 AM

Oh, and the circuit opening relay is behind the passenger side kick panel.

Here, this will help you locate any others and identifies the pin numbers which correspond to the wiring diagrams:
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=014

12-28-2011, 07:36 AM	#1
Jay633 3" Exhaust Join Date: Mar 2010 Location: Oxnard Posts: 109	checking relays Im sorry I tried looking but didn't get much info. Can I put a wire on the spades and turn the ignition switch to on then put the tester on the wires and see if there's power in all spades?

12-28-2011, 08:48 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	It depends on the relay but the basic functionality is generally the same... You just need to figure out which pin is which. I found this cool picture sometime back that I've been saving... Just waiting for the day that I could actually point to a graphic when I say: 85 and 86 are the coil; 30 is the constant (power supply or ground); 87a is the "Normally Closed" and 87 is the "Normally Open". When power is applied across the coil the generated magnetic field throws the switch inside opening the circuit between 30 and 87a and closing the circuit between 30 and 87. This is what's generally known as a "Bosch" type relay. So look at the TEWD and figure out which pins are the coil and which are the switch. Measure across the switch when the coil is powered and when it's not. Which relay is it? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-29-2011, 01:07 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Look in the TEWD, it shows which pins are the coil. Test the coil to make sure it's not broken (if you use the conductivity test setting, the one that beeps, it should beep). Then put the leads on the other two pins (the switch) and touch the coil leads with a 9 volt battery or another voltage source up to 12v. When the coil has power, the meter should beep indicating that the switch is good. That's as much as I can simplify the process, it's really easy but having a set of test leads with alligator clips and not the straight probes REALLY helps. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-29-2011, 01:12 AM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Oh, and the circuit opening relay is behind the passenger side kick panel. Here, this will help you locate any others and identifies the pin numbers which correspond to the wiring diagrams: http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=014 __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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12-28-2011, 05:18 PM	#3
Jay633 3" Exhaust Join Date: Mar 2010 Location: Oxnard Posts: 109	The relays I want to check are the efi relay.l Fog light relay. And the circuit opening relay even though im having trouble find that one