I wrote this up last year and just joined this board not too long ago so I wanted to share this with you guys.
Well a lot of people have been asking how to install fogs on a non-prewired MR-2 (most likely a 91) and so I thought a write up was needed
First: to verify you do not have the wiring harness, look in the main fuse box under the hood and look for the location of where the fogs relay would be. You can also look in the gap where the fog lights should sit and if you find a wire harness that is tied back, then you are prewired. Same goes if you find a wire tucked up under the dash where the switch goes. If there are wire connectors in the location, you are prewired and you have a lot less to worry about.
I am working with a 1991 N/A
Materials to buy:
-Relay and connector
-roll of 16-gauge or thicker wire
-10 female wire connectors
-4 male wire connectors
-In-line fuse
-wire strippers
-Fogs
-Switch, OEM or aftermarket (84160-17030)
-Brackets
left bracket (52126-17010)
right bracket (52125-17010)
clip (90467-14038) - You'll need 2 of these, one for each bracket.
(part numbers courtesy of Gsus in
this thread )
1.) You will need to either find a generic fog light relay kit or make your own. you can buy relays at any auto parts store with the connector.
Once you have the relay, split out several feet of wire so that you only have a single wire instead of two tied together, unless you bought single strand wire
On four long pieces of wire, strip about a 1/4 inch of insulation off and connect a female connector on each end. Make sure that the female connectors fit correctly on the relay.
If you cannot find a relay that does not have a socket to fit into, dont worry. The female connects fit snugly on the relay, for it is meant to be connected that way. If you do have the socket, the female connectors fit into the socket, but you will have to bent the back of the connector where there are slots cut into the connector. This will allow the connectors to grab into the socket and not be pushed out when you push in the relay.
Each slot in the relay has a specific location that needs to be wired correctly. The following pictures show what the relay socket looks like and a wiring diagram to decipher the locations of the relay
Please mind my crude wiring diagram
The middle slot is unused in this application
*I am not sure of the correct terminology for the connector of the relay so i will refer to it as the relay socket*
2.) once you have four wires connected to the relay socket, roughly lay out the wires to the desired locations.
The switch is easiest to keep as a double bundled wire (like a stereo system wire) because you will need to run one wire through the firewall to the switch, then back through to the corner light.
Alternatives to wiring to corner light: If for some reason you would like to have the fogs on without any other lights on, wire up the signal wire (switch wire) to the switch, then to the cigarette lighter. The lights will turn off when the car is off, but you will have to manually turn them on/off if you do not wish for them to be on during the day
*the signal/switch wire is not used to provide power to the fogs, but as a voltage source to kick the relay on. The relay opens up power directly from the battery*