H4 bulb wattage dilemma
 

I have a 1982 300sd. Stock wiring and relays. I just got my Bosch H4 euros. The good folks at Capitol West Co. in Sacramento, CA. sent me a pair of high wattage bulbs I ordered. 100/90w H4 P43T Xenon Halogene in the Heliolite brand. Wiletta who owns the place said that she uses these in her 78 Mercedes and a 1991 model with no problems and has done so for five years.

Daniel Stern lighting emailed me and said, "You must stick with stock wattage to use your existing wiring. There is a persistent (and incorrect) rumor that Mercedes are so well built that you can safely and effectively run high-wattage headlamp bulbs without damage. Do so at your own great risk.

Use ultra high efficacy H4 bulbs, $17/ea, and H3 Gold bulbs, $13/ea."

Any of you have a definitive answer for me before I damage something?

Maybe Wiletta is one of those drivers I finger at night as they pass by on I-5 as I drive thru Sackatomato , I am tired of oncoming cars with blue or green or some kinda colored bright halogens, blinding oncoming drivers.

Be aware that besides excessive voltage drop in the wiring, you are likely to melt the socket and or bulb housing depending on what vehicle its going in. Putting hi wattage bulbs in later MB's (124, 201 etc) is prone to causing damaging to the headlite assy.
Case in point. A local shop replaced a melted headlight assy after they found the car's owner, a woman, had installed 100 W bulbs in it. A few months later same dame came in *****ing about one of her lights went out again, saying they must not have done a very good job, it cost a lot of $$ for those new headlites, blah blah blah :(
Inspection showed that someone had stuck in another 100W bulb. I believe they told her in no uncertain terms, no warranties for her lights and don't bring it back for this again!

The problem with the 300SD is the headlights are no good from the get go. Find some Euro headlites and use a Hella +30 55 Watt bulbs and you will be in great shape!

Electricity works according to pretty simple rules.

You need to first determine if your circuitry can handle the current demand of the lighting you are using.

Watts/Voltage = Current draw

So 100/12 = 8.33A per high beam. If both headlamps are on the same cicuit then double that, if high beams and headlights are on at the same time, quadruple it. Then add a little for wiggle room.

I just checked the wiring diagrams for my car, and they show a circuit for each high and low beam, at 8A each - which is not sufficient for the lamps you have. Don't substitute a higher rated fuse unless you also replace all the wiring attached to it.

Next comes heat. Most of the energy going into an incandescent lamp becomes heat, relatively little becomes light.

Basically I wouldn't do it.

Kevin

I'm a bit confused by the statement "stock wiring and relays" statement in the original post......

If the wiring is stock you don't have any relays involved, if on the other hand you have added relays then it seems to me you don't have a stock set-up anymore.

Euro lights have no problem handling high-power bulbs, I've been running 100/80 watt bulbs (with upgraded wiring and relays) for years - they work great.

In spite of what others have said here there is no comparision between "high-output" 55w bulbs and a 100W high beam.

Reverend, I thought we had put this to rest. The definitive answer is as follows:

If you have to run higher wattage bulbs then you must install proper relays to run them.

There is an excellent article on HID lights and the proper use of them at http://www.intellexual.net/hid.html. They usually get all the blame for the blue/purple glaring lights, but when they are done correctly with the correct bulbs and housings, there is nothing wrong with using them.

Halogens don't usually give off the blue/purple light unless someone has tinted them or their lenses. However, 90W low beams are about as pleasant to oncoming drivers as just running with your high beams on. In fact, I think normal high beams are 60W - 80W.

modern halgoen high beams range from 55 to 65 watts.

http://www.danielsternlighting.com/tech/bulbs/bulb_types/bulb_types.html

I think this settles it
 

I think this settles this in my mind. I appreciate the opinions. I think I am going to return the bulbs and not take any chances. Thanks.

noooooooooooooooooo
 

check the diy pages here for a simple lighting change. it is complete with pix.

I had higher . . .
 

. . wattage bulbs in my MB and they have been there for 6 years (didn't know they were there!). The wiring was fine as well as the plastic connector that mates with the H4 bulb; no burning, etc.

I replaced them (w/ a legal version) and cleaned the inside of the glass. Details contained on my page, Menu#26.

They do make H-4 55/100 watt bulbs..........Low beams nobody gets blinded........and high beams you are going to blind them regarless of wattage.

I put one in My Harley shortly after I almost went through a barbed wire fence one night when I didn't see the road make a 90 degree right turn , I barely got stopped in time. THat would have been a ugly thing to do on a bike.
Been running one ever since 1983.

I'm inclined to think that the 55/100's would be acceptable using the existing wiring for the simple reason that the high beams are only on for a very limited time, and, therefore, the capability to build heat is simply not there.

But, if you were to run them for hours on end............................... :confused:

I would expect an 8A fuse, the standard for the high beam circuit, to blow with a 100W load.

Kevin

Something is not right here, Kevin.

The standard 60W high beams would use 10 amps for two bulbs, correct? :confused:

Brian

Yes, if both were on the same circuit. But they're not. There's a different circuit for each high beam - and hence a distinct 8A fuse for each. At least according to my shop manual CD.

Kevin

OK, I had not even bothered to look.

So, one 100W bulb will draw 8.3 amps at 12V.

The fuse will likely survive this. Remember, unless you have a dead short, the fuse will take quite awhile to melt at the rated load. It might take just about forever to melt at 8.3 amps.

Additionally, the draw will probably be closer to 7.4 amps with a properly functioning alternator.

Remember, wire becomes more restrictive as it ages. Even if you use only the stock wattage, you can get an upgrade in light performance by using relays and larger wiring. If you have a 15% drop in voltage, you loose about 47% of light (according to Hella).

I use relays on my 2002 Golf and I noticed an improvement in headlamp performance.

I believe you meant resistive, not restrictive. Wire should not get more resistive as it ages, if it does, then it has become corroded or something.
Insulation does get more brittle after a long time especially in high heat areas. Its true that a 3% drop in voltage will give a large (15% or so) drop in light output. Relays help prevent drop, use them when upgrading that is the general practice.

I'd recommend the 55/100w lights over what you have. Wiring a relay in for the high beams is pretty simple. Run a heavy hot wire from the battery (with a fusible link installed for safety) to the Relay supply terminal, with the other side of the relay switched terminal going to the high beams. Run the ground terminal of the relay to a good ground (could even ground it where you mount the relay), and use the original high beam wire to trigger the relay.

First off...go here and view...very easy...

http://brandon.importtransmissionexchange.com/benz_files/lights.htm

Secondly...
55/100w bulbs (off of a 12.5v battery) pull 6 amps on low and 8 on high. I measured it with a Amp meter before I installed them in the car.

I would not recommend using stock wiring as anyone with a w126 knows, when you hit the heater switch your headlights dim and all sorts of power dropping issues.
Its not a matter of excessive amperage per-say but more a matter of voltage drop by the time you get to the end of the wire at the bulb. Light output drops significantly as V drops away at a small rate.

The upgrade to 55/100 is amazing and in the time I have been running them, only had one person high-beam flash me (there was a hill).
My friends say its acceptable light output in their eyes when I am behind them. The cutoff on the Euro H4's helps this a lot...just make sure you take GREAT care and aim them CORRECTLY..

Brandon :)

If you run a high beam at the fuse rating for any length of time, it will age very quickly. Standard engineering procedure is to fuse the circuit with 50% margin. A 100W high beam will draw 7 amps, I would not run it with less than a 10A fuse. Make sure your wiring can withstand it.

What brand of bulbs are you running?
 

Puma has got the Hella H4 bulbs in a 55/60 wattage that draw about 10amps in the Xenon Premium bulb.

They also have the Narva german made bulb in a 55/100 watt but it would pull 200 watts on the switch and 17 amps at high beam.
I guess these you could get away with since you don't run the high beams much - especially if you added a fuesed relay.

I looked at the Sylvania silverstar H4 bulbs and they are more expensive than the Hella or Narva. One of the guys on the forum put in the silverstar bulbs in his Euros and likes them.

Which brand? I'm going to stick with 55/60 watt

Brands of bulbs is like brands of oil filters.

I use the Hella's for no good reason other than the fact that the vendor also sold me the Hella replacement headlights.

I have come to find out, from him, that Hella does not make their own H4 lamps.................. just puts their name on another manufacturer's bulb.

Back to the oil filter BS all over again...................

yeap yeap. I like Narva bulbs, but they are hard to find in the US. Dan Stern carries them.

I use 80W/100W H4 bulbs in Hella 7" conversion lamps. They are running off of an upgraded wiring harness and relay assembly. I have never been flashed because the lights are bothering oncoming traffic. The sharp beam cutoff and proper aiming prevent any problems. The only time I have seen problems with "blue bulbs" or high wattage bulbs is in stock headlights without a sharp cutoff. I do hate Honda and Nissan headlights. Those are blinding.