headlight relay install

[nostatic]

Well, I finally got some time to install Marcus Sucro's relay kit. It is not the most sano work, but nothing has exploded yet. The kit is $20 shipped, and is well labeled:
http://members.rennlist.com/msucro1/relaykit.htm


There is plenty of room under the fuse box, and I didn't really want to drill anything. so I used the existing screw that mounts the fuse box and mounted the relay setup that way:

One wire goes to the battery, so I added a ring terminal to the lead and added it to the battery terminal. For chassis ground I used a ring terminal and mounted to the nearest fender bolt:


The only annoyance was that the yellow and white wires that lead into the top of the fuse terminals have a copper sheath that did not want to work with a butt connector. Again, I didn't want to do any cutting, so I wrapped the end from the relay around the wire/sheath and wrapped it with electrical tape. Suboptimal, but it seems to work:

The clean install would have involved running the wires from the relay under the fuse box, but it didn't seem easy (seemed like I would have had to pull the whole assembly). It appears as though there is plenty of open space above the fuses under the case, so I just fed them down through the bottom. I was going to go out the side but again I would have had to cut the fuse box cover:


It isn't pretty, but it seems to work. If anyone has a suggestion for the wire-wire connection let me know. I'm from the jury-rig school of twist-and-tape.

[RoninLB]

nostatic...hard to critique it from here..I guess you read all the pervious threads on the relay install...you can drive over here and I'll help make it bullet proff.....I'm only in Long Beach......Ron

[nostatic]

Hi Ron...right Beach (Long), wrong coast though

The main kludge I'd like to clean up is the connection between the original white and yellow wires and the relay wires. The factory wires appear to have a copper box sheath on the end. I'd rather not cut it off. Is there some sort of standard connector that fits these so I can make a clean jumper?

[RoninLB]

nostatic...I suggest solder all wires, everything, all wire terminals, etc..and the chassis ground is better than battery ground [that's another story]..I used a small bolt that makes a clean contact with the body on the outside..the bolt from the outside to a wire terminal on the inside with a clean body contact, with a washer and nut..I don't like sheet metal screws , especially on a critical component..use anti corrosion on everything..and if you want a clean contact for a wire going to fuse box because the original is bad use a dab of solder to turn the lose wires into a solid connection..I would not use bigger bulbs in stock headlite feed wires.....and electrical projects are great..a little brains/info/skill/tools/patience and it becomes a reflection on the entire 911.....and you did fuse the hot wire from battery???...for another project a 2nd ground to engine starter case connecting to tranny mount bolt is cool.. and spitting out electrical info/knowledge impresses the so called intelleginsia............Ron

[nostatic]

Thanks for the tips. I didn't use a flying fuse for the hot lead, but that should make it into version 2 of the install, along with proper soldering. I assumed using the fender mount bolt for chassis ground was OK (and preferable to the battery terminal). Should I just drill a fresh hold below the fuse box and screw the ground in there? I still get a lump in my throat when considering pulling out the power drill.

[Rot 911]

Hey Nostatic, you are turning into a not half bad mechanic. Just took the right car to get you started! In all seriousness, I would submit this as a tech tip article to Wayne. I plan on ordering the relays and will use your thread as a good how to install manual.

[RoninLB]

a good solid connection is important.your fender/any fender must have a solid/good ground . secondary is a "clean" install.......Ron

[jwill911]

Hi nostatic,

I installed the M. Sucros relay kit ~ year ago. Like you I used the lower fuse box mount screw to mount the relays. I did however lift the whole fuse box to route all the wires underneath to make it cleaner looking. If you are interested I can take a couple of digitals tonight. To be honest I don't remember where I got the ground from, I'll have to look to refresh my memory. Works great. My next plan is for H4s.

Regards,
jwill

[Big Dave 928]

So what bulbs can you now use with that relay?

[nostatic]

Not sure what the system is now rated at, but I am running what I believe are stock H4s. As has been stated here before, even if you are running factory bulbs you should have the relays, otherwise you will end up replacing your headlight and/or turn signal switches. The factory in their infinite wisdom has all of the current for the lights running through the headlight and turn signal switches (for high beams). Over time the turn signal switch eventually gives up as the contacts fail.

[82SuperC]

I also used the Marcus Sucro relay kit. Pretty good setup. I am running the 55/100W H4 bulbs. I believe you can run the 80/100W without a problem with these relays in place. As far as the brass lugs on the factory wires, I cut them off and used a solder lug spade connector and soldered the factory wires and the relay wires to M/F ends. Then simply plugged together. Makes for an easy disconnect also. I guess if you wanted to leave the factory brass ends on, you could buy spade lugs that were large enough to accept them and solder or crimp them in place, and still have this setup. I also loosened the fuse box and ran the wires underneath and behind for the clean installation. Hope this helps.

[vesnyder]

I am using Sucro's relays and recently installed H4 100/90's - some zenon bulbs I got off eBay. They are bright and white, certainly a different color than I am used to. So far, so good!

I need to go in and run the wires behind the fuse box - much cleaner. That mounting spot seems to work best.

[RoninLB]

real 100/80 Narva[German] bulbs should damage[at least] stock bulb sockets..Bosch makes a bulb socket that can handle big watts..but if you do a 130/100w you will have to rewire from relay to bulb socket...I would suggest 10ga for high/130 and 12ga for low/100 ....not a pro/this is what I did...............Ron

[nostatic]

Nice work JB. So you didn't need to pull the whole fuse block to get them under? Also, where is your chassis ground running to?

[82SuperC]

Hello Nostatic:
BTW, I'm don't participate much on these threads, I just read alot and enjoy the entertainment and information passed along by those in the know, but I sure did enjoy the drama surrounding your pursuit of the right P-Car and boy did you score.

Anyway, I ran the white ground white up towards the shock tower. It just so happened on my car, there was a large bolt located in the middle of the shock tower which had the paint removed, possibly by the PO. You can see the white wire running along the filler tube and then attached to the bolt on the shock tower. Don't know if this is there on other cars. There was another ground already in place so I just hooked right in.

Oh, and I did loosen the whole fuse block and lifted it forward a bit. Don't recall it being a problem.

[arcsine]

What do you gentelmen recommend the fuse rating be for the hot lead to the battery?

[Early_S_Man]

Actually, yo don't have to worry about getting the ceramic Bosch headlamp socket, though it would be nice if someone posted a readily availablw source!

If you attach a plastic-coated pinout diagram, and color-code for YOUR wiring inside each headlamp bucket there isn't a problem using 10 ga or 12 ga wires with uninsulated 1/4" Faston connectors, crimped AND soldered to the three wires! There isn't any risk of shorting after the wires are attached to the headlamp assemblies, whether H1 or H4, or the H4 'conversion' units!

[jwill911]

While we're on the subject of head light relays etc. I've been think my next project on my ~87 Carrera might be H4's and I've seen them sold by everybody and their brother. What's the difference? Can someone educate me on the subject so I don't find out after I've bought the wrong ones. Or from the wrong vendor. I know you need to have the rims painted to match. I thought it might be a good time to have some other minor pieces painted, like a rear valance just in case I go back to the single out muffler. Or god forbid sell the car. Might find an RS America I can't pass up.

TIA

[nostatic]

Originally posted by Gary Carlton What do you gentelmen recommend the fuse rating be for the hot lead to the battery?

I seem to recall a suggestion of 25amp for the flying fuse.

[RoninLB]

Warren...the Bosh bulb sockets that I used are from this lighting supplier...prices are competitive..it's a great site for an education on what is really happening w/headlights..........Ron

http://lighting.mbz.org/tech/