911 Posted 3February Report Share Posted 3February Hi everyone, Finally got around to installing the J-west headlight relay on my 1987 911 and have hit a bit of a roadblock. Does anyone have a photo of their fuse panel with the headlight relay installed. The instructions state there are only meant to be x2 wires (one yellow and one white) in positions 1-4 of fusebox number 2. However I've got x4 wires. Two white, one yellow and one yellow and black as pictured. Now I've mounted the relay kit to positions 1 and 3 as per instructions, but there are still two wires in position 2 and 4. Doesn't seem like I've installed it correctly. Has anyone got a solution for the additional wires. May only be applicable to the later 3.2s, or might be an Aussie car thing. Thanks Quote Link to comment Share on other sites More sharing options...
Peter M Posted 3February Report Share Posted 3February Ross, Some fuseboxes used internal "jumpers" between the two low beam and the two high beam fuses so only required one yellow wire and one white wire at the top of the box. These "jumpers" are usually just a strip of brass or copper strip located at the rear of the fusebox that connects those pairs of upper fuse contacts blocks together. The J West instructions I saw on line show a internally jumped fusebox. Evidently your fuse box doesn't have these internal connectors and requires each pair of low and high beam fuses to be powered separately by the wiring harness. Hence you have a pair of whites and a pair of yellows. If a bit unsure, just check what's powered up with your checklight/multimeter when low beam is on and then when high beam is activated. Quote Link to comment Share on other sites More sharing options...
911 Posted 3February Author Report Share Posted 3February Thanks for the reply Peter. If that is the case would that mean the J-West relay does not work with the configuration in the fusebox? You would essentially need two of the kits? Quote Link to comment Share on other sites More sharing options...
davidtran Posted 3February Report Share Posted 3February I have the same problems with my car. Same 4 wires. I did not install and gave up for now. In page in book you posted maybe the extra wire is for left and right that's what I thought. I did not test though. Been busy. If this was the case, I had idea to install relay to x1 yellow and x1 white wire. Disconnect the other two and run a bridge wire from connected yellow to other yellow and connected white to other white with additional small wire and then isolate the yellow and white wire not in use? Buy two relays would be annoying solutions. Has to be better way. Then I watched jWest video on YouTube and saw at the end of the video that they say one white wire is thicker and one yellow wire has black stripe and if your car like this it's for dimming headlights to make parking lights brighter. My car has black stripe on yellow wire, but can't tell if white wire thicker. I can't tell in your picture too. Watch from 24 minutes onwards in the video. It explains. Maybe that is the solutions? Quote Link to comment Share on other sites More sharing options...
Peter M Posted 3February Report Share Posted 3February 10 hours ago, 911 said: Thanks for the reply Peter. If that is the case would that mean the J-West relay does not work with the configuration in the fusebox? You would essentially need two of the kits? No, one set of relays if all you need. Whilst the factory fusebox has separate fuses for low beam left, low beam right, high beam left and high beam right, you only need to tap into one low beam circuit and one highbeam circuit to tigger the relay (ie power up the coil to close the relay contacts). Did J West give you a circuit diagram that you could post? That may make it easier to describe the required connections. Hang in there, it's worth the effort! Quote Link to comment Share on other sites More sharing options...
Peter M Posted 3February Report Share Posted 3February Here's a better video showing all the colours clearly that will be easier to discuss: Quote Link to comment Share on other sites More sharing options...
911 Posted 3February Author Report Share Posted 3February 19 minutes ago, Peter M said: No, one set of relays if all you need. Whilst the factory fusebox has separate fuses for low beam left, low beam right, high beam left and high beam right, you only need to tap into one low beam circuit and one highbeam circuit to tigger the relay (ie power up the coil to close the relay contacts). Did J West give you a circuit diagram that you could post? That may make it easier to describe the required connections. Hang in there, it's worth the effort! J-West didn't really offer a solution or any diagrams. I just have the extract above from the Bentley manual. I get what you're saying, but if there is no jumper and they're each left/right, high/low are one their own fuse and I connect the relay to one yellow and one white, that would mean that the other two are still getting power directly from the battery, so only one side is protected by the relay? 38 minutes ago, davidtran said: I have the same problems with my car. Same 4 wires. I did not install and gave up for now. In page in book you posted maybe the extra wire is for left and right that's what I thought. I did not test though. Been busy. If this was the case, I had idea to install relay to x1 yellow and x1 white wire. Disconnect the other two and run a bridge wire from connected yellow to other yellow and connected white to other white with additional small wire and then isolate the yellow and white wire not in use? Buy two relays would be annoying solutions. Has to be better way. Then I watched jWest video on YouTube and saw at the end of the video that they say one white wire is thicker and one yellow wire has black stripe and if your car like this it's for dimming headlights to make parking lights brighter. My car has black stripe on yellow wire, but can't tell if white wire thicker. I can't tell in your picture too. Watch from 24 minutes onwards in the video. It explains. Maybe that is the solutions? Thanks David. That's interesting. I have 2 whites (I'd need to check the thickness), one yellow and one yellow and black as per the video. Strange as my car is Australian delivered, not an import. Definitely has me confused. The bridging you mention makes sense. I'm just not sure if that's the right way of doing it. Definately wouldn't be right if it's got a dimmer as video mentions. 8 minutes ago, Peter M said: Here's a better video showing all the colours clearly that will be easier to discuss: I've seen that video when trying to find a solution, but it's the same as the video David posted. Has the bridged left/right high and low beams you mentioned above. Quote Link to comment Share on other sites More sharing options...
Peter M Posted 3February Report Share Posted 3February So I've looked at the wiring diagram and it clearly shows jumper connections in the fusebox between the high and low fuses pairs, so ignore what I said above! Can't figure out where those extra yellow and white wires are from though! (Unless Porsche doubled up the wires from the switch in later years to reduce voltage drop and improve headlight performance?) Took a look at mine and I've just ignored the extra wires which aligns with what is shown on the circuit diagram. Ie. I've just taken one yellow and one white and connected them to the J West yellow and white pair and then reconnected the blue and green back to the top of the fuses to the same places I took the original yellow and white. Quote Link to comment Share on other sites More sharing options...
911 Posted 3February Author Report Share Posted 3February Exactly what I did. Although you've done fuses 5 and 7 working from the front of the car back. I've done fuses 8 and 6 as per my photo. I'm not convinced they're jumped at the back. I think two of the wires serve a different purpose. I'm glad to see your car is the same though. Must be a later car thing, as David's is also a later car. Thenplot thickens. Kept me up last night trying to figure out what the wires are for. I almost wanted to take the fuse box out to see if they're jumped, but it looks like a bit of work. You'll notice that your wires are different too. You'll have positions: 8 - white thick wire 7 - white thin wire 6 - yellow 5 - yellow and black stripe I just took a better photo. You'll notice the white wires are a different thickness too, which makes me think they're not there to reduce voltage. Peter M 1 Quote Link to comment Share on other sites More sharing options...
davidtran Posted 4February Report Share Posted 4February Mine is exact same. I looked at the wires. White ones looks similar thickness but I have one yellow and one yellow with black line. So do you know what to do. How to make the relay kit work? Quote Link to comment Share on other sites More sharing options...
Peter M Posted 4February Report Share Posted 4February 6 minutes ago, davidtran said: Mine is exact same. I looked at the wires. White ones looks similar thickness but I have one yellow and one yellow with black line. So do you know what to do. How to make the relay kit work? Just connect it up as per the instructions and don't let the extra yellow and white wires worry you. Quote Link to comment Share on other sites More sharing options...
davidtran Posted 4February Report Share Posted 4February 37 minutes ago, Peter M said: Just connect it up as per the instructions and don't let the extra yellow and white wires worry you. Thanks Peter but you and 911 have both got different setup. I have added a photo just to understand. 911 has blue wire in position 1, green wire in position 3 and positions 2 and 4 are factory specifications You have blue wire in position 2 and green wire in positions 4. Positions 1 and 3 are factory specifications for you. Where i am confused is that these are not jumpered like the other cars with only 2 wires from what you're both saying. So that would mean one of you, or both of have installed relay wrong? If positions 1 was jumpered with 2 and positions 3 was jumpered with 4 it would not matter and both of your installs would be correct? Sorry. Hope that makes sense just trying to understand. This is why I just left it and didn't finish installing. Just want to know what correct way is and what all 4 wires actually do Quote Link to comment Share on other sites More sharing options...
911 Posted 4February Author Report Share Posted 4February I think if fuses 1/2 and 3/4 have a jumper on the rear, both Peter and I have installed correctly. So either way is fine. I can't test them at the moment as I'm away from the car, but if fuses do not have a jumper, then I have no idea what the correct way to install is.... As I'm thinking two of the feed wires would run through the relay and the other two would run as normal, which would defeat the purpose of the relay if all four wires are linked to the headlights. I watched the J-West video you posted and that's confused me even more, as it specifically mentions the yellow/black and thinner white wire being linked to dimming of the headlights to increase brightness of the parking lights.. Peter has a more extensive knowledge of these cars than myself, so I'd go with what he thinks. I'm hoping the fuses have a jumper, so that I don't need to diddle around anymore, but I doubt it. It's never that easy. Quote Link to comment Share on other sites More sharing options...
Peter M Posted 4February Report Share Posted 4February I apologise for speculating about "jumpers" before I looked at the wiring diagram or even my own car as I've just created confusion. I've been working on converting a Moto Morini fusebox to a Moto Guzzi which involves installing copper jumper connections at the rear of the fusebox ..... Anyway, Ross is correct, there are jumpers built into the fuse box connecting the fuses 1 & 2 together (White, high beam left and right headlights respectively) and fuses 3 & 4 (Yellow, low beam left and right respectively. The wiring diagram above shows this. Just be aware that J West number the fuses in an opposite direction! ie 8 & 7 and 6 & 5 As long as you have the white that came from either 1 or 2 and the yellow from either 3 or 4 connected to the same coloured wires from the relay you are OK. When you turn on the lights, this will energise the coil in the appropriate relay (depending on the hi/lo switch position) and close the circuit, allowing power from the battery to flow directly to the appropriate pair of fuses (since they linked with a jumper behind the fusebox) through either the blue or green wire depending on the hi/lo switch position and then to the headlights. There is nothing obviously wrong that I can see with what you a have done in the photo. If you are unsure, leave one of the battery cables disconnected from the battery, turn on the headlights, then go to the front of the car and carefully touch the loose cable to the battery and the headlights should illuminate like never before. Disconnect then flick the hi beam switch and test again. If there are no lights or the loose battery connector sparks excessively when lightly touched against the battery terminal, there is something wrong. Quote Link to comment Share on other sites More sharing options...
davidtran Posted 4February Report Share Posted 4February Thanks Peter. Makes a bit more sense. So your way is correct and 911 way correct too with what you're saying. As long as any of the yellow and any of the white is connected. Quote Link to comment Share on other sites More sharing options...
911 Posted 4February Author Report Share Posted 4February 1 hour ago, Peter M said: I apologise for speculating about "jumpers" before I looked at the wiring diagram or even my own car as I've just created confusion. I've been working on converting a Moto Morini fusebox to a Moto Guzzi which involves installing copper jumper connections at the rear of the fusebox ..... Anyway, Ross is correct, there are jumpers built into the fuse box connecting the fuses 1 & 2 together (White, high beam left and right headlights respectively) and fuses 3 & 4 (Yellow, low beam left and right respectively. The wiring diagram above shows this. Just be aware that J West number the fuses in an opposite direction! ie 8 & 7 and 6 & 5 As long as you have the white that came from either 1 or 2 and the yellow from either 3 or 4 connected to the same coloured wires from the relay you are OK. When you turn on the lights, this will energise the coil in the appropriate relay (depending on the hi/lo switch position) and close the circuit, allowing power from the battery to flow directly to the appropriate pair of fuses (since they linked with a jumper behind the fusebox) through either the blue or green wire depending on the hi/lo switch position and then to the headlights. There is nothing obviously wrong that I can see with what you a have done in the photo. If you are unsure, leave one of the battery cables disconnected from the battery, turn on the headlights, then go to the front of the car and carefully touch the loose cable to the battery and the headlights should illuminate like never before. Disconnect then flick the hi beam switch and test again. If there are no lights or the loose battery connector sparks excessively when lightly touched against the battery terminal, there is something wrong. From J-West: Have you just tried using the non-striped yellow and white input wires and ignoring the black striped ones? That is the solution for the late cars that are not from somewhere with like Sweden with special wiring. So I think my way is OK. Peter M 1 Quote Link to comment Share on other sites More sharing options...
Peter M Posted 4February Report Share Posted 4February 45 minutes ago, davidtran said: Thanks Peter. Makes a bit more sense. So your way is correct and 911 way correct too with what you're saying. As long as any of the yellow and any of the white is connected. Just the plain yellow and the plain white according to the circuit diagram I posted above. If you are still not sure, pull the 4 fuses and just check the top fuse box contacts with your test light/multimeter. All the relays want to be told is that you have turned on either the low beam or high beam. The other wires do the heavy lifting. Also drawing a diagram often clears my thinking when relays are involved. Quote Link to comment Share on other sites More sharing options...
911 Posted 4February Author Report Share Posted 4February Did you test any of your wires Peter? Or just follow the instructions? Are you certain in your car 1/2 and 3/4 are jumped 9n the rear. J-West said to connect wires to positions 1 and 3 as per my photo and to leave wires in positions 2 and 4 alone as per the later cars (ours). You have connected to 2 and 4.. If Jumped shouldn't matter though. Quote Link to comment Share on other sites More sharing options...
Peter M Posted 4February Report Share Posted 4February 2 hours ago, 911 said: Did you test any of your wires Peter? Or just follow the instructions? Are you certain in your car 1/2 and 3/4 are jumped 9n the rear. J-West said to connect wires to positions 1 and 3 as per my photo and to leave wires in positions 2 and 4 alone as per the later cars (ours). You have connected to 2 and 4.. If Jumped shouldn't matter though. I did at the time, which is about 8 years ago now, just as a double check. I don't recall anything from J West regarding early and late cars and certainly the comments about Swedish cars are all new to me. I wish I hadn't mentioned the jumpers now as it's just confused things. They are clearly shown on the circuit diagram above and that's why J West give you the options. Plus I've been happy with the performance of my headlights since the install! As for me using 1 & 3 rather than 2 & 4, it just shows I'm odd....sorry couldn't resist a maths joke! 911 1 Quote Link to comment Share on other sites More sharing options...
davidtran Posted 4February Report Share Posted 4February I did installation. Finished just before as per 911 photo and Jwest message. I took photo but don't know how to upload. It's same as 991 picture though. I installed at positions 1 and 3, or 6 and 8 if you go from front of car like jWest say. Couldn't tell if there was bridge for the connections without taking fuses box apart. Hardest parts was connecting the positive and earth terminals. Barely any room on my positive batt terminal and my earth strap was same. Thanks 911 and Peter. At least I has a productive Sunday. If I didn't do it today it would be in the drawer for few years yet. 911 and Peter M 2 Quote Link to comment Share on other sites More sharing options...
911 Posted 4February Author Report Share Posted 4February 1 hour ago, Peter M said: I did at the time, which is about 8 years ago now, just as a double check. I don't recall anything from J West regarding early and late cars and certainly the comments about Swedish cars are all new to me. I wish I hadn't mentioned the jumpers now as it's just confused things. They are clearly shown on the circuit diagram above and that's why J West give you the options. Plus I've been happy with the performance of my headlights since the install! As for me using 1 & 3 rather than 2 & 4, it just shows I'm odd....sorry couldn't resist a maths joke! I've used 1 and 3, you've used 2 and 4, so I'm the odd one 😂 I might test all 4 wires when I get a chance, just because curiosity has got the better of me. Peter M 1 Quote Link to comment Share on other sites More sharing options...
sus911 Posted 7February Report Share Posted 7February Is it possible to test the installation by just pulling the new relays and checking for headlight/high beam operation? Quote Link to comment Share on other sites More sharing options...
Peter M Posted 9February Report Share Posted 9February On 08/02/2024 at 08:13, sus911 said: Is it possible to test the installation by just pulling the new relays and checking for headlight/high beam operation? Yes, pulling the relays will just mean you get darkness Phil! 😁 I think we have made heavy weather on this. Just connect it up and if you don't enjoy brighter lights just means something is wrong. sus911 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.