fog lights wont work!

twan · 10-09-2009, 03:31 AM

crap it didnt make a difference! i even read the end of the link to the forum and it said for 1988 supras u have to connect the new fuse to the red-yellow wire instead of the red-black wire. i give up...

Busted Knuckles · 10-10-2009, 11:34 AM

Did you check if the relay works before you did anything else, as I suggested? If the relay is bad, the re-wire will not work. Also, the directions said to verify the wire functions first. You'll need a multimeter or test light.

The re-wire needs the high-powered side of the relay to also be powered. You may need to also cut this wire and connect it to a new fused circuit. Myself, I'd run a new line from the battery, fuse it at the battery, and run it to the high powered side of the relay.

twan · 10-10-2009, 08:19 PM

hey yeah i checked the relay and even swapped it with the defogger. so then i went to parts source and got a "mini-add a circuit" where u take out a fuse and replace it with this thingy that has two fuse slots and a 12v wire coming out the side. so now i just to to check to see if i got the high power wire going from the fuse is going to the relay. i do remember it being the thicker wire of the 4 and it was red with yellow stripe.

and where do i hook on my ohm reader? if i knew what all eight wires did i prob would have this tackled by now lol.

thanks for the help so far!

twan · 10-10-2009, 08:21 PM

hey yeah i checked the relay and even swapped it with the defogger. so then i went to parts source and got a "mini-add a circuit" where u take out a fuse and replace it with this thingy that has two fuse slots and a 12v wire coming out the side. so now i just to to check to see if i got the high power wire going from the fuse is going to the relay. i do remember it being the thicker wire of the 4 and it was red with yellow stripe.

and where do i hook on my ohm reader? if i knew what all eight wires did i prob would have this tackled by now lol.

thanks for the help so far!

cre · 10-11-2009, 03:17 AM

Wiring diagram: http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=076

That diagram is for a later model, as you've noticed, the wiring colors vary, but the routing is the same.

In stock form, the fog lights are are routed through the headlight switch (has it's own contacts, so a damaged switch is possible) thus requiring the headlights to be turned on for the fogs to light; the fog light switch; and the fog light relay.

If you do find that the relay is closing when the aforementioned requirements are met, but still no fogs, test for voltage at the foglight housings... it could be bad bulbs or grounds.

And it's not an ohm meter... an ohm is a measure of resistance and in this case such measurements would do you no good.

For this you'd be using a volt meter or (more likely) a multi-meter (rather commonly referred to as a DMM - Digital Multi-Meter).

Also, be careful with the stock relays, they're not always interchangeable and you could damage something you don't want to pay to replace. They're not like Bosch relays which are pretty much standardized (except for a few uncommon types).

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10-09-2009, 03:31 AM	#1
twan Stock Join Date: Oct 2009 Location: TORONTO Posts: 20	crap it didnt make a difference! i even read the end of the link to the forum and it said for 1988 supras u have to connect the new fuse to the red-yellow wire instead of the red-black wire. i give up...

10-10-2009, 11:34 AM	#2
Busted Knuckles 12psi boost Join Date: Dec 2007 Location: Atlanta Posts: 300	Did you check if the relay works before you did anything else, as I suggested? If the relay is bad, the re-wire will not work. Also, the directions said to verify the wire functions first. You'll need a multimeter or test light. The re-wire needs the high-powered side of the relay to also be powered. You may need to also cut this wire and connect it to a new fused circuit. Myself, I'd run a new line from the battery, fuse it at the battery, and run it to the high powered side of the relay.

10-10-2009, 08:19 PM	#3
twan Stock Join Date: Oct 2009 Location: TORONTO Posts: 20	hey yeah i checked the relay and even swapped it with the defogger. so then i went to parts source and got a "mini-add a circuit" where u take out a fuse and replace it with this thingy that has two fuse slots and a 12v wire coming out the side. so now i just to to check to see if i got the high power wire going from the fuse is going to the relay. i do remember it being the thicker wire of the 4 and it was red with yellow stripe. and where do i hook on my ohm reader? if i knew what all eight wires did i prob would have this tackled by now lol. thanks for the help so far!

10-10-2009, 08:21 PM	#4
twan Stock Join Date: Oct 2009 Location: TORONTO Posts: 20	hey yeah i checked the relay and even swapped it with the defogger. so then i went to parts source and got a "mini-add a circuit" where u take out a fuse and replace it with this thingy that has two fuse slots and a 12v wire coming out the side. so now i just to to check to see if i got the high power wire going from the fuse is going to the relay. i do remember it being the thicker wire of the 4 and it was red with yellow stripe. and where do i hook on my ohm reader? if i knew what all eight wires did i prob would have this tackled by now lol. thanks for the help so far!

10-11-2009, 03:17 AM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Wiring diagram: http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=076 That diagram is for a later model, as you've noticed, the wiring colors vary, but the routing is the same. In stock form, the fog lights are are routed through the headlight switch (has it's own contacts, so a damaged switch is possible) thus requiring the headlights to be turned on for the fogs to light; the fog light switch; and the fog light relay. If you do find that the relay is closing when the aforementioned requirements are met, but still no fogs, test for voltage at the foglight housings... it could be bad bulbs or grounds. And it's not an ohm meter... an ohm is a measure of resistance and in this case such measurements would do you no good. For this you'd be using a volt meter or (more likely) a multi-meter (rather commonly referred to as a DMM - Digital Multi-Meter). Also, be careful with the stock relays, they're not always interchangeable and you could damage something you don't want to pay to replace. They're not like Bosch relays which are pretty much standardized (except for a few uncommon types).