high wattage headlight bulb .

Ive been having a problem with my 80w/100w high watt headlight bulbs keep blowing just my drivers side harness. I have a high temp harness on it but just the drivers side harness keeps blowing, the passenger side has been fine for a year now. My question is what can i do to keep these from blowing the harness? There has to be a way. If i need to add some resistors/relays could someone please explain to me how to do that. I already have two 50w/6ohm resistors so if those will work by themselves that will be great but if i need a relay as well please also state what kind and how to wire it up along with the how to wire the resistors. Thanks in advance, it will really help my out.

Get a thicker harness - if it is overheating, it doesn't have enough copper. (Unless it is heat conduction from the bulb - the get silicon insulation etc.) Forget resistors - use a smaller bulb. Apart from the bulbs only being about 0.5 & 0.4 Ohms, dropping their voltage significantly drops their output. (Though I suspect you already have a significant voltage drop anyhow....!) It would be interesting to measure the voltage across the bulb versus the battery....

I had an issue a few years ago with high wattage bulbs blowing.  I thought it was a current issue, so i added a realy to draw current directly from the battery.  After that, the issue went away. If your cousin is such a good installer, and he will install anything for a 6 pack; why are you talking to me?

surely you had ought to be running high wattage bulbs through a relayed harness with much larger than stick wiring. Just putting a heavy duty connector onto the end of factory wiring will do you no good as you will still have the voltage drop of the factory wiring to deal with which in turn increases current draw and heat.

Ahhhh! I misread - I thought it was the harness that was blowing. You probably have a bad connection. Bulbs blow thru thermal (& electric) shock and thermal cycling. You get that with bad connections - short breaks in power. Disconnect and reconnect all connectors including the ground path - that's to scratch thru any contamination and remake good contact. (Unscrew/re-screw body grounds; sand, steel-wool or wire brush ground surfaces. And rotate any fuses involved.) If that fails, repeat with contact cleaner or start looking for an intermittent break somewhere, else an intermittent short to ground...

afdanw wrote: I had an issue a few years ago with high wattage bulbs blowing.  I thought it was a current issue, so i added a realy to draw current directly from the battery.  After that, the issue went away.

hey what kind of relay did you get that will hook up to the battery? can you tell me how to hook it up to both headlights too?, relays confuse the heck out of me. thanks.

hey guys would this relay work? if so, could you tell how to wire it up? you might have to copy paste this because i couldnt get it to link up. RELAY

rocco1005 wrote: afdanw wrote: I had an issue a few years ago with high wattage bulbs blowing.  I thought it was a current issue, so i added a realy to draw current directly from the battery.  After that, the issue went away.  hey what kind of relay did you get that will hook up to the battery? can you tell me how to hook it up to both headlights too?, relays confuse the heck out of me. thanks.

This is a quesion i cannot answer.  I do not have enough info from you to give a good answer.  First question i need is: Do you have 2 single filiment bulbs, or one duel filiment bulb per headlight housing?  Question 2: when you change between high and low beams does the positive change, or the negative?  Most cars it is the posative, but in some (including mine) the negative switches.  Since you dont already know what kind of relay to use, or how to wire it correctly, i would say just buy a relay harness online that is made for your specific size bulbs, for about $20-$30.  Then you dont have to do anything but plug it in, and wire one lead to the pos battery terminal, and one to the neg.  The relay harness will allow you to get current directly from the battery, and possibly more current (depending on the wattage bulbs used) with the potental for more light output.  Also the harness use thicker guage wire to handle the current/ heat better.  I think that would be the best option for you if you wanted to add relays. 

If your cousin is such a good installer, and he will install anything for a 6 pack; why are you talking to me?

If you can get a voltmeter or multimeter and measure the voltage across the bulb compared to the battery voltage. IMO there should not be more than 0.5V difference, though some consider 1V acceptable and - if I understand some texts correctly - a 3V difference is the "accepted maximum". (No way IMHO!) Although intermittent contact is the biggest reason for light bulb failure, in the case of halogens, too low a voltage can also be a cause. (Low voltage = not hot enough = deposits = early failure.) Hence why a relay and better cable can help - lower voltage drop. That's aside from maybe bypassing the intermittent break as well as supplying a higher voltage and hence a MUCH higher light output. (What is it for a halogen - a 10% lower voltage can mean 20% or 30% less light output? (Plus earlier falure.)