H4 headlamp upgrade
 

This seems very straightforward except for the high power relay, has any one done this
and is there wiring involved ?

minus the relay, there's nothing to it.. i did the upgrade about a week after i first got the car. it IS just a straight plug-in.. and the performance is literally like night and day..

Jeff

Are you saying I don't need the relay ?

Brian, without some direction where do I start, I have pulled down my fuse panel and seen the relays, do I just plug in the new relays, if so where ?. Could you look and let me know. I am mechanical but electricaly
challenged.

Brian, that would be great
Thanks alot
neal

I am a little confused by the previous posts on this H4 upgrade...I need clarification.

I have installed the H4 headlights with the bulbs out o' th' Hella box (55W/60W I think?) and was not aware that the relay had to be installed unless higher wattage bulbs (like the 80W/100W) were used. (Higher wattage bulbs are illegal for street use) I also thought that the USA stock sealed beam headlight units were about 55W as well...which would then make sense not to need a high power relay. I guess my question is...

What is the maximum wattage H4 Halogen bulbs that can be used without a relay?

My original post was not meant to say that a relay is not needed, just how simple it is if you choose to go without it. Like Brian, i was affraid of a meltdown, so i went with the safe side couple of days after i did the H4 install(plus mine were the 80w's). I've got a similar setup for my new foglights, and i think the diagram for that is pretty straightforward. I've scanned it and posted it at http://www.env-cai.csupomona.edu/admins/jeff/temp/relay.gif
80/100 H4's.. and 55/60 fogs.. people see me coming at them.. http://www.pelicanparts.com/ultimate/smile.gif

HTH,

Jeff

Jeff,

Those are called "retina burners"...now with your airhorn and the headers and the lights...everyone will know you are coming...

Bob form Pelican parts send me these instructions, my question is there a spare relay spot on the fuse panel or do I mount the relay remotely ?


Hi Neal,

Basically, it is just a matter of routing the wires that go to the from the switch to the headlight to
terminals 85 (the brown wire goes here--it is ground) and 86 of the relay. Then connect a
heavy-gauge wire directly from the battery to terminal 30, and a heavy-gauge wire from terminal 87
to the headlight. Also, the closer the relay is to the headlights the better it works.

Here is a diagram of the internal workings of the Bosch relay:

I very strongly suggest that you put a fuse in line between the battery and the relay. Preferably within 18" wire run from the battery. There are a number of different in-line fuse gizmos that you can buy.

Watts = amps * volts. For 100W lights, that's 200W (both lights) / 12.5V = 16 amps. So a single 20 Amp fuse should be good enough.

--

I have done more research on the lighting upgrade/relay issue...

Headlights: According to Haynes and the Pelican catalog, the USA stock sealed beam headlights are 55/60 watts, high and low beam...same as Hella H4 units with the 'stock bulb' (55/60W). It shouldn't make any difference electrically speaking, which lamp is installed. If there are heat-related problems in the switches/relay/wiring, then the car has other problems and while a relay may appear to solve the problem it really only masks it. I would think then that it should be ok to use the 55/60W H4 lights without a relay. Relays/fuses would be required to increase the lamp wattages from their stock wattages. As an aside, I don't know others experience, but when I had the H4's (55/60W lamps) installed for month or two, I didn't notice much difference in the lighting quality or characteristics from sealed beams, nor heat problems either.

Fog/driving lights: The stock lamps are 35 watts. H3 lamp upgrades are 55 and 100 watts...relays/fuses are therefore required.

One other thing that hasn't been said is that relays need to be installed for the headlight high and low beam circuits as well as the fog light circuit if these stock lamp values are exceeded to protect the wiring and switches. As many as 3 relays in all may be needed for a 914 lighting upgrade.

[This message has been edited by bowlsby (edited 01-24-2000).]