head light relays

[leverpuller]

Are the necessary on an 82SC with the h4s i bought from ajusa?

[austria3]

not necessary but a good option to improve the brightness of your head light and especially to improve the life of the high beam switch

[magic930]

Probably do, but it depends on the bulb wattage. If they are 55/65 then you are probably OK. If they are 80/100 then they will burn out the switch in the steering column. Relays are cheap $5-10 at an autoparts store and the wiring is easy. You need at least 2 relays one for each bulb. You can also use 4 relays one for each high/low combination.

[peter915]

I used one of the standard fuse box relays. My car had A/C fitted at one time (now removed) and the relay for this was still in place. I used this relay for High-Beam, looks neat - differance was well worth it - much brighter.
I would try and source standard relay mount and fit alongside exsisting relays.

[Nine9six]

Yeah, go ahead and install h4's without a relay...Just be sure to set aside an extra $130 to replace the column switch, which will soon weld the little contacts together. They cant take the heat/current.
Do a search on sucro. Marcus Sucro provides a relay setup with easy to follow instructions for about $25.

[vash]

i made my own kit, but i have used the sucro one. damn easy to install. changing that column switch is the opposite. it is a exercise in patience, yoga, tai chi, cussing,....not in any particular order. get the relays.

[Wil Ferch]

Normal or high-wattage....it's insane to run full headlight current through the dinky little steering column switch...Porsche gaffed on this one....

I can't see how someone can say it's OK with stock bulbs and not OK with hi-watt. Think about this. With a relay kit the load on the steering column switch is reduced by a FACTOR of 100x or more.....high watt bulbs are bigger than stock by a FACTOR of maybe 1.8x to 2.0x ...it's even simple to do the math in one's head why a relay is needed in all cases...

Wil

[Early_S_Man]

If they are 55/65 then you are probably OK.

Yep, typical NASAthink before the Challenger and Columbia disasters ...

I have said this many times before ... the 911 control stalk switches were designed for 45/40 Watt Type 'A' bulbs in 1964!!! The use of 60/55 Watt bulbs will wear out the stock switches if you do significant night driving ... and when the failure occurs, you will most likely be on a dark, lonely, road in inclement weather! Have you ever contemplated trying to sleep for 5 - 8 hours in your 911 waiting for the sun to come up in 35°F weather?

I am not a fan of the Sucro kits ... for no other reason other than the fact that I don't believe they are necessary! Buy your own relays [four of them] along with 12 ga or 10 ga wire and some good quality Faston connectors and circuit breakers ...and do your own work! There are posts you can find with an appropriate search string that illustrate the process!

[Superman]

One of the most important upgrades for our cars. Relay those headlights. For reliability and brightness. Then upgrade to the 55/100 bulbs. Like driving in daylight.

[klaucke]

I'm with Warren, this is so easy to do without the Sucro kit I don't see why it should be used. Not to mention that its 25 dollars for two relays and some wiring which can be purchased for under 10 bucks otherwise. Or you can go Warren's route and install 4 relays (still cheaper than Sucro kit) to have the best set-up possible, it provides more reliable lighting in case of a component failure.

With H4s the relay is neccessary, especially when you consider how inexpensive it is to put in the relays vs. a new column switch. I've had to replace my switch b/c a PO didn't install relays, and it hurt to spend that kind of money on something that was easily avoidable.

[Wil Ferch]

Whether you wish to "roll your own" or buy a ready-made Sucro kit ( still inexpensive for what it is...including a nice set of instructions)... a relay will lessen the load on the switch contacts to much less than a fraction of an amp ( maybe 1/100 A)...vs 8A ( stock) or 16-18A ( high output).

A "must do" for reliability and longevity....

Wil

[leverpuller]

thanks everyone!!!!! looks like another project...... oh yeah.......

[dmcummins]

Do the H1's also require a relay?

[Wil Ferch]

Dmcummins...did you even read what I said above.... ???? Answer: yes....H1's need relays too.

Since this seems to be a problem with the *clarity* of my communication style..let me try another set of words....

From the factory... Porsche did not use relays. This is altogether a design weakness. Let me first ask...do we all know what a relay is...and what it is intended to do ? A relay is nothing more than an electrically-operating switch. One side of the relay, the "control" circuit- is an electromagnet that ( when its energized with REALLY LOW power draw) ..closes a set of contacts for the "power" circuit - - the "other" side of the relay. Got a picture of that? If your hand operates a wall light switch in a room for instance...your "hand" would be similar to this electromagnet..it simply "flips the switch" when the electromagnet is energized. Why are relays used? Obviously, the power draw of the "flipping" circuit is MUCH, MUCH lower than the power demands of the "power" circuit.

So...whether you have stock 55/60 Watt bulbs ( and the system doesn't know if they're housed in H1 or H4 style units !)...or you have 100/130 Watt bulbs.... the amp draw of these things range from roughly 6-8 Amps to about 16-18 Amps. The "control" ( or electromagnet) circuit of a relay takes...maybe 0.14-0.2 Amp....MUCH LOWER. This is the lower amount of "oompfh" that the steering column switch now sees. With relays, the steering column switch completes the "control" circuit to the electromagnet of the relay, which in turn closes the power contacts to the headlights. The full power circuit is ( now) never seen by the steering column switch anymore.... and it WILL LIVE much longer and not fuse shut over time.

Is this better... I hope... ??

- Wil

EDIT...corrected control amp value in above text to "early-S-man" value in later post to this thread ( 0.14-0.2 A)

[cegerer]

If I'm reading you correctly Wil, H1's require 1 relay and H4's require 4 relays?

[vash]

i still want to relay protect my power window switches. anybody got a sketch on a napkin or something? i figured it would be the same as the headlight relays i made right? just hook it to the fuses label "windows".
what i need to do is get off my ass and make a powered fuse block so i dont have so many freaking power lines coming off the + battery side. makes the protective cover not so protective.

[FrayAdjacent911]

Like Will explained, every headlight arrangment SHOULD have a relay controlling the circuit. Even with the lowly 7" sealed beam headlights, all of the current that is powering them goes through the wiring to the dash and the switch. This is not good in any situation.

With older cars, corrosion on the wires and contacts can cause resistance lowering the voltage to the headlights, and can degrade the performance thereof.

I've read here that someone installed a relay kit with sealed beam headlights, and noticed an improvement.

So I think it is definitely DEFINITELY recommended if one switches to any sort of 'upgraded' headlight arrangement.

[911pcars]

"If I'm reading you correctly Wil, H1's require 1 relay and H4's require 4 relays?"

I'll pre-empt Wil with MHO. Theoretically, a single 30A Bosch-type relay shoud be able to control 360 watts (12V x 30A). You have two headlights. With sufficient overhead, one relay per headlight should be fine.

Sherwood

[cegerer]

You do realize my comment was in jest, Sherwood? My way of saying that the headlight relay issue has been completely beat to death .... Wil, Warren, RoninLB and others have done a great job explaining this issue many, many times (btw: a search reveals 271 threads on the 911 Tech Forum regarding headlight relays. )

[randywebb]

just a tad mo' beatin'....

Anybody that thinks the unchanged, stock configuration doesn't need a relay should read the above post by FrayAdjacent911