993 - Adding rear fog lights
From pcarworkshop
Warning! rear fog lights are designed only to be used during severe weather or dense fog conditions where normal visibility is greatly effected. Because the nature of the rear fog light's brightly lit bulbs it is not recommended that they be used during normal weather conditions. Using the rear fog lights in normal weather condition may cause road rage or may even result you in a traffic ticket.
Rear Fog Light pictures in the dark
I took these pictures early in the morning prior to day light in almost complete dark conditions. These pictures can be used as a reference of how bright the rear fog lights are compared to the parking lights. The bulbs used in the rear fog lights are the same wattage bulbs that is used for regular brake lights.
This DIY originated from Gert in Belgium, Gert did this DIY on his 993 and kindly passed his knowledgeable experience and information to me to make this DIY possible for U.S. 993 owners who want to add this option to their 993.
993 rear fog lights are standard equipment in Europe but was not installed in the U.S. bonded 993s. Since our U.S. 993s are not pre wired for the rear fog light, this DIY is maybe slightly complicated.
Some of the major component of this DIY includes:
- Porsche fog light switch
- 2 x fog light bulb sockets
- 2 x light bulb
- Wire
- Tools needed:
- Philips screw driver
- Flat screw driver
- 4 mm allen key
- 5 mm allen key
- Snap ring plier
- Radio removal key
- Razor blade
- X-acto knife
- Steel cable
- Electrical tape
Optional tools:
- Soldering iron
- Heat shrink tubes
- Wire ties
Parts List:
Part number Description QTY Price
- 1 pc 90063113290 Bulb 12v-1.2w
- 1 pc 91161321303 Face Plate
- 1 pc 9116130281001C Knob
- 1 pc 96461314900 Fog lamp switch
- 1 pc 99361325200 Rear fog light cap
- 2 pc 00072195701 Radio removal tool
- 10 feet Home Depot Steel cable
- 1 pc Home Depot Razor blade
- 1 pc Home Depot X-acto knife blade
- 1 pc Home Depot Electrical tape
- 1 pc Nissan Dealer Generic light socket
- 2 pc Pep Boys Rear fog light light bulb
- 8 pc Radio Shack Wire tie
- 50 ft Radio Shack Wire
DIY steps: (In order)
Contents |
Rear fog light switch install
The rear fog light switch is located on the right side of the front fog light switch in the center of the dash above the radio. This DIY section will show you how to install the rear fog light switch.
(1). Before proceeding to the first step please ensure that you have your radio code card handy, because installation of this switch requires the removal of the radio and in order to reactivate the radio a security code must be entered.
(2). In order to correctly remove the factory radio a set of 2 keys must be used simultaneously to pull the radio out of the DIN chassis. Each key can be used as either right or left side key, the direction is etched on the key itself to guide you on which side it should be used.
(3). Remove the security face plate, insert the two key into the horizontal slot and slowly pull the radio out.
(4). Once the radio is out of the DIN chassis disconnect the power, antenna connection from behind.
(5). Use a tool to pull the DIN chassis's tabs down so the DIN chassis can also be pulled out of the radio slot. The tabs were bent up from the factory to keep the DIN chassis in place. Removing the DIN chassis will aid the installation of the rear fog light switch. (Be careful the edges of the DIn chassis are sharp and will cut your hands)
(6). Unscrew and remove the front fog light switch by turning it counter-clockwise, use a snap ring plier to unscrew the plastic switch holder nut. Be careful to make sure the snap ring plier have a good grip on it before you start to turn it. The cap is made of plastic and can be easily stripped if you slip. You may need to hold the switch from behind to aid the removal of the plastic nut.
(7). After removing the front fog light switch you now have a good idea what size hole to cut on the blank slot on the right of the front fog light switch. Use a x-acto knife carefully cut the dash blank switch hole out.
(Before continuing on, wiring to the rear fog light switch should be completed before installation of the switch)
(8). Unwrapped the black tape on back of the front fog light switch to reveal the wires to the front fog lights. Locate the brown and gray/blue wire from the front fog light switch and use the razor blade to make a splice opening for wires to be connect to it. The new factory fog light switch to be used as the rear fog light switch does not come with any wire connections, so you will have to make your own soldering to connect wires to the back of the rear fog light switch, or find a suitable female connector. (Check the end of this page to get the complete wiring connection of the rear fog light switch). Splice the wire from Pin#31 of the rear fog light switch to the brown wire of the front fog light switch. Splice the wire from Pin #58 of the rear fog light switch to the gray/blue wire. Solder the splice is possible and tape up the individual splices with electrical tape and the completed unit.
(9). Hold rear fog light switch from behind the dash board and screw the plastic cap nut from the front of the dash board and tighten it with the snap ring plier. Do the same for the front fog light switch.
(10). Reinstall the radio DIN chassis bend the tabs, re-connect the radio connectors and the antenna back to the radio and insert the radio.
(11). At this point you should have two wire hanging from the inside of the dash board, 1 wire to go to the fuse box area and one wire to the rear of the car.
Rear fog light wiring (wiring to the rear fog light switch should be completed before installation of the switch), from the back of the rear fog light switch
- Pin #31 connects to the brown wire of the front fog light switch
- Pin #58 connects to the gray/blue wire of the front fog light switch
- Pin #1 connects to the rear fog lights at the rear
- Pin #15 connects to the white/yellow wire of the R34 relay in the fuse box
Fuse Box
This DIY section will show you how to run the wire from pin# 15 of the rear fog light switch to the fuse box.
(1). Open the front trunk lift the carpet to reveal the fuse box. Remove the plastic sleeve held on by a rubber strip that stretch across the width of the car.
(2). Run the wire from pin# 15 of the rear fog light switch from behind the radio to the rubber grommet underneath the passenger side dash board near the front firewall.
(3). Tape the wire from pin# 15 to the end of a steel cable and use a sharp object to puncture a hole through the rubber grommet and push the steel cable + wire combo through the rubber grommet so they can be fetched in the front trunk firewall area that is covered by the plastic sleeve. Remove the wire from the steel cable and pull the steel cable back through the rubber grommet from the inside of the car.
(4). Use a 5 mm allen key to loosen the fuse panel mounting bolt and unscrew the thumb screw at the opposite end to lift the fuse panel up.
(5). Make a splice opening on the white/yellow wire under the relay# R34 on the fuse box splice in the wire from pin# 15 of the rear fog light switch which you have just pushed up through the rubber grommet of the firewall. Solder the splice if possible and tape the splice with electrical tape.
(6). Reinstall the fuse panel and plastic sleeve
Wire run to the engine compartment
This DIY section will show you how to run the wire from pin# 1 of the rear fog light switch to the engine compartment.
(1). Lift and remove the passenger floor mat, and pull the base carpet up. Undo the two philips screws on the passenger foot well panel, and 1 plastic cap. Run the wire from pin #1 of the rear fog light switch under the passenger foot well panel.
(2). Lift the passenger side rail by pulling up on the ends of the plastic rail. Run the wire underneath the rail and secure it with some electrical tape. Tuck the wire on the side panel of the passenger side rear seat area.
(3). Fold the rear seat down and remove the 4 philips screw that secure the rear firewall cover to the engine bay. Remove the covering by pulling it forward. Disconnect the speaker wires to allow the cover to be moved further away from the firewall.
(4). Locate the rubber grommet on the bottom passenger side corner.
(\5). Tape the end of the wire to the steel cable puncture the rubber boot with a shape object and push the steel cable/wire combo through to the engine compartment.
(6). Reach in from the engine compartment and pull the wire off the steel cable and pull the slack off.
(7). Reinstall the rear seat cover, make sure all the wire is tucked in on the passenger side rail, and foot well cover.
Rear Lens Removal
This DIY section will show you how to remove the rear lens and prepare the wire run to the rear lens area.
(1). Unscrew the philips screw at the rear signal lens on each side and remove only the right side lens by unplugging the wire connector at each bulb. Just leave the left side signal lens hangng on the wire.
(2). Open the engine deck lid, turn the rear lens panel plastic bolt 90 degrees with a flat screw driver. Use a plier or a tweezers to pull the plastic cap off first before attempting to remove the panel. If you pull the panel up with the plastic caps still inserted in there they may fly up and become MIA inside your engine bay area.
(3). Loosen the three 4 mm allen bolt caps and remove the plastic caps together with the bolt.
(4). Loosen the three embedded philips screw to so the top of the screw is flush with the rear lens top panel.
(5). Pull the lens towards you to remove the rear lens. Unscrew the philips screw that holds the wiring plug for the rear lens in place, disconnect the connector to the backup light.
(6). Pull the snorkel off and the air filter box, and remove the air box cover. Reach in on the right side of the engine bay and remove the electronic cover that houses some wire blocks and wire harness. It is a little tricky to get this cover off, you may have to play with different angles in order to successfully removing it.
(7). Feed the wire that you ran from inside of the car to the engine bay area under the existing factory wire harness wire tie, so that it looks like part of the factory wiring. Find the rubber boot on the right corner of the car after the harness cover have been removed. Tape the end of the wire to the steel cable and puncture the rubber boot with the wire / steel cable combo through and pull it through on the other side of the rubber boot behind the right signal lens.
(8). Wire tie the wire to the existing factory harness and use as much of the factory clip as possible to secure the wire. Cramp a female connector on the end of that wire, that is where it will connect to the rear fog light wiring connection.
Rear Fog Light Socket Integration
This DIY section will show you how to integrate the rear fog light socket into the rear lens and the power feed.
(1). When working on the socket integration lay the rear lens on a towel to prevent scratches to the lens.
(2). Find the two factory dummy plugs for the rear fog light opening and twist off the dummy plug from the rear lens.
(3). You will need to find a generic single element light bulb socket plug that will fit the rear len fog light opening. Neither Porsche or Hela sells the sockets by themselves, they want you to buy the whole f$%en rear lens. With help form Gert I found the generic wire from a Nissan dealer (The good guys?) The fit is not perfect and there are some minor modification needed before the sockets will fit, but this is not an item that you will be putting on and off all the time and once on it is fairly tight it is also water prove so it is good enough for me.
(4). Carefully cut open the black tubing with a sharp razor blade on the back up light wire harness on both sides of the rear lens near the rear fog light plug to reveal the two wire on the inside, on the right side backup light there are three wires, either one of the brown wires can be used. Make a splice on the brown wire of the backup light wire and connect the negative wire of the rear fog light socket to the splice, and solder the connection if possible. Finish up using electrical tape to seal the opening. When done correctly as you can see from the last picture that it looks like part of the factory wiring.
Note: On a light bulb socket the center contact point is the positive contact, the surrounding base is the negative.
(5). Connect the two positive wire of the rear fog light socket together and cramp in a male connector to be connected to the female end on the car. Place that positive wire with the backup light wire harness and secure it under the factory wire clip.
(6). Insert the light bulb in the socket and push and turn the socket in place.
(7). Reinstall the rear lens make sure now you connect both the backup light connector and the single rear fog light connector.
Ready for test. Remember, the rear fog lights can only be operated when the engine in turned on in conjunction with the front fog light switch being turned on.
Original Article Credit : Robin Sun
