Help with headlight/driving light rewire project

Stevehose

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I am going to wire my driving lights and put a relay on the low beam circuit. Thanks to HBChris I have a correct relay socket coming in order to keep things stock looking under the hood. This will be used for the low beams, the Hella 160's will have its relay hidden under the left light access panel, I'll put the fuses there also. The Hella circuit will also have a plug so I can remove the headlights and leave the wires if I decide to. Please check my circuit diagram and make any suggestions/corrections. Also, what gauge wire should I use for the relay-to-lights circuits, and what amperage fuse should I use for the low beam, high beam, and driving light circuits? Does this affect the existing highbeam fuse amperage in the fuse block? Should the switch-to-relay circuits be fused also? I'll post progress of the project. Thanks.

(DELETED FIRST DRAWING - INCORRECT)
 
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jmackro

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I don't think the lower right corner of your wiring diagram is correct. That is, you show the low beam relay driven directly from the headlight switch, while the high beam relay is driven from what you call the "high beam switch". That would suggest that the low beams are on all the time, and the "high beam switch" additionally turns on the highs.

The way our cars are wired is that the headlight switch feeds what I would call the "low-high switch", and the low-high switch selects EITHER the low beams, OR the high beam relay.

My coupe does not have fog lights, so my wiring diagram is a bit simpler. When I added a relay to the low beam circuit (and again, HBChris assisted me) I just snipped the low beam wire (yellow as I recall) connected it to the new relay, drew power off the high beam relay, and was done. Again, since the low beam and high beam aren't both on at the same time, one fuse will suffice for powering both relays.
 
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sfdon

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Couple thoughts for you..

I just bought another set of Lows AND Highs [4 lamps total] from ClassicGarage- $160 bucks- quite a good deal....
http://classicgarage.com/53hehekit.html

15 amp fuse is good

West Marine carries very nice waterproof fuse holders AND correct color LB wire.
I always use new wire and bigger gauge running to both LB bulbs
You can twin the alternator wire for an original early look and a homerun + voltage and current.

Have you been to Daniel Sterns Website?

http://www.danielsternlighting.com/tech/relays/relays.html

I take the ground wire eyelet on both sides and soak in phosphoric acid...
I take the ground screw out, throw it away and dremel the screw hole to bare metal, all the + battery voltage in the world is worthless without a comparable ground.

HomeDepot now carries the nice 3M friction tape.

Have fun!
 

HB Chris

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Jay is correct, hi-lo switch is the trigger for both beams. Yellow wire can trigger both lo and fog relays, they shouldn't be on on when hi is on. I used red 10g power lead to relay, you can unclip the red hi beam power lead, snip the female plug and add a wire and new plug to also lead to the lo relay for power. I would think 8 amps is sufficient but I am not an expert. The safest thing to do is add an inline fuse under the steering column for the power wire to the hi-lo switch before it heads out to the relays. Ask Spence at Mesa what happened to his coupe when there are no fuses on that wire. Get the wiring diagram in the Blue Books, pre `73 U.S. it really helps. Almost forgot, BMW still sells the proper wire wrap tape, it isn't sticky like Eastwood's, cost is $22 though but worth it.

Chris
 

61porsche

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Suggestion

Steve,

I would suggest the fuses shown to protect the lights be moved to the bat supply to the relays. Should a problem occur, only one circuit is/ would be effected.

The added benefit of correctly wired relays is that the amount of current/ amps running through the original switch is now minimal- only enough to make the relay work. What this means is that the switch lasts infinately longer and the amount of amps available for the device is much greater.

On 6v cars ( Early Porsche), this is done all the time- starter, lights, etc. But in any case is not a substitute to find the root of a problem. Amps, volts, bad devices, loose wires, bad solder joints, etc.

On the site Don provided is the calculation for turning watts into amps and therefore the fuse sizes needed. If you bought driving/ rally lights vs. fog lights, it may be different.

Jerry
 

Stevehose

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Revised schematic

I appreciate all the input, I forgot that the low beams have a high circuit in them, I have revised my drawing to include this and the relocation of the fuses. Since these are driving lights and not fog, I have them wired to come on with the high beams. If something still doesnt look correct please let me know. Should I take the relay input + current from the alternator or the battery post - does it matter? Should I fuse the + from the battery to the headlight switch or from the headlight switch to the beam switch? Thanks.

 

HB Chris

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Take it from the battery, that is what provides the current for the horn and hi beam relays now. Fusing the headlight switch to dip switch is simplest approach and the headlight switches go bad occassionally but the farthest upstream fuse makes sense as well.
 

HB Chris

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If you have the right positive cable like this one it has multiple mounting points for the relays. You may need to ask for an e21 or e24 application though. I got mine from Mesa.
 

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Stevehose

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Which color wire is the main feed for the light switch from the battery? The wiring diagram shows 2 red wires going in, both from the fuse box. If the low beams aren't fused, where is the + coming from battery to the switch so I can fuse that and protect the dip switch behind it. Also, here is gratuitous photo of the project-in-progress taken yesterday - beautiful crisp day here!




Take it from the battery, that is what provides the current for the horn and hi beam relays now. Fusing the headlight switch to dip switch is simplest approach and the headlight switches go bad occassionally but the farthest upstream fuse makes sense as well.
 

HB Chris

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Steve,

Which wiring diagram are you using? The pre `74 and `74 and later are slightly different. The early ones shows red from ignition switch terminal 30 to unprotected side of fuse 5 which is bridged to fuse 4 as well. From the unprotected side of fuse 4 a red wire goes to the light switch terminal 30. A yellow/white wire leaves th light switch from terminal 56 headed for the dip switch terminal 56. It gets real complicated! That is why I suggested you fuse it near the dip switch, easy to get to and it no longer carries the load of the headlights, it just trips the relays. Hope this helps.
 

Stevehose

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I have a 72 diagram and it is exactly as you describe now that I can decipher it and understand it is fed from the unprotected side of the fuse box. With that in mind, shouldn't I then fuse the red wire between fuse box #4 and the light switch in order to protect both the light and dip switches if one of them shorts? The load of the headlights will have been relocated to the new relay by the battery so the only load is from the relays or am i still missing something here. Why they didn't protect the low beam circuit is beyond me. Thanks.


Steve,

Which wiring diagram are you using? The pre `74 and `74 and later are slightly different. The early ones shows red from ignition switch terminal 30 to unprotected side of fuse 5 which is bridged to fuse 4 as well. From the unprotected side of fuse 4 a red wire goes to the light switch terminal 30. A yellow/white wire leaves th light switch from terminal 56 headed for the dip switch terminal 56. It gets real complicated! That is why I suggested you fuse it near the dip switch, easy to get to and it no longer carries the load of the headlights, it just trips the relays. Hope this helps.
 

HB Chris

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Yes, you can do that and it is the safest way to go. My `69 2002 had no fuses or relays on both low and high beam, strange to say the least.
 

deQuincey

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Also, here is gratuitous photo of the project-in-progress taken yesterday - beautiful crisp day here!

beautiful day, and beautiful car, too
congratulations !
 

Stevehose

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Finished!

Thanks to HBChris for the relay socket, I successfully relayed and fused the low beam circuit, fused the high beam circuit, and relayed and fused some vintage driving lights, all keeping a reasonably stock look under the hood and making my low beams brighter and the overall light circuits much safer.

I removed the battery and unwrapped the original harness, the single white wire coming off the left side of the high beam relay is the factory wire to activate the driving light relay when the high beams are engaged. Not shown here is that later I cut this wire and ran wires from this to a switch on my steering column (hole was already there from a PO-installed airhorn switch), this enables me to switch the driving lights on or off when the high beams are on:



Here's the switch, the LED lit up indicates that the driving lights are on:



I cut the yellow low beam headlight wire and wired it to the new relay. The side of the yellow wire coming from the dash is now used to activate the relay instead of bearing the full load of the lights, much safer and now brighter! The yellow wire side from the headlights goes to the out side of the relay. I wired a fused segment from the battery to both low and high beam relays as well as the new driving light relay which is hidden under the headlight access plate. So all lights have direct battery connection with heavy gauge wire. Then re-taped the harness with new friction tape:



And installed back in the holders with the cool unobtainium Hella can relays, left to right - low beam, high beam, horn:



Ready for the Autobahn!
 

deQuincey

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I appreciate all the input, I forgot that the low beams have a high circuit in them, I have revised my drawing to include this and the relocation of the fuses.

very good !

please, the drawing has dissappeared, cqn you post it again

regards
 

Stevehose

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I revised the drawing to show the driving light on/off switch which is wired between the high beam and driving light relays if you want to install one. If the switch is lighted then it will need a ground as indicated. Peace of mind knowing the low and high beams are fused and relayed!


very good !

please, the drawing has dissappeared, cqn you post it again

regards
 

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deQuincey

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thank you

now the last question

where did you find those lights, and how did you attach them to the front central bumper ?

regards
 

Stevehose

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Am happy to answer all questions. Mounting: I (gasp) drilled the bumpers for the proper sized hole after measuring several times. But not after finding a bumper section on eBay that is in nicer shape than mine to keep in case I want to go back to stock I can put the center section back in. If you don't want to drill you can get these:

http://cgi.ebay.com/ebaymotors/Hella-Cibie-Bosch-Lucas-Fog-Driving-Light-Clamps-NEW-_W0QQcmdZViewItemQQhashZitem3f0683233aQQitemZ270692197178QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

They allow you to clamp them to the bumper instead of drilling. I have these and used them to see if I liked the look of the lights then I found the bumper so I drilled. Drilling will keep the lights from "bouncing" more when driving. I have 2 sets of Hella's - the first I got from Germany which turned out to be nice & new but misrepresented by KCI, the second are some old but nice condition ones I got off eBay - they're from the late 60's-early 70's and look like they came with the car - nice chrome workmanship and cool glass molds and just the right amount of ageing on them. They came with the mounting hardware:





now the last question

where did you find those lights, and how did you attach them to the front central bumper ?

regards
 

afeustel

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Picking up an old thread - headlights and relays

A few questions:

1) why would my high beam E1 (Euro H1??) Hellas appear to be frosted / white-ish lens?
2) why are they as bright as Xenon lights like the ones that light up the runway for the Space Shuttle?

3) when installing the low beam relay out near the battery, do folks run a new heavy guage wire out to the lights themselves, or just split the low beam feed from the dip switch so that the switch-side now activates the relay and the light-side still carries the load, which is now fed from the nearby battey to the relay?

4) can somebody point me to a wiring diagram for a 72 E9/E3?

Thanks
Drew
 
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