Headlight voltage drop

[valleyman]

For what it's worth I just measured the voltage drop in the driver's side headlight at highbeam. With 14.24 reading across the battery terminals and 14.0 showing on the digital voltmeter gauge in the console at 2k rpm the voltage measured across the highbeam as the wiring entered connector #1021, which is essentially the bulb socket, was only 11.68. I'm probably going to add the headlight relays from Mad Electrical to see if it makes a difference.

All of this was occasioned by my disappointment in switching to the PIAA #9007 bulbs last night. Yes, they are a little brighter but not $80.00 worth IMHO. :bandit:

[Hotrauder]

I haven't measured the voltage as I am very happy with mine. I found them on Ebay and sniped them at about $50.00 which was enough thanx. I still haven't installed the H1's however. Dennis;)

[grampaws]

Tried piaa's silverstas where better and cheaper!

threw the pias out!
a 2volt drop is quite significant..there could be
a voltage regulator in the circuit to maintain bulb life..
a bad connection or corroded wire..checking the wiring
for hot spots can help locate any faults..
the relay is a good start...

[69mach1]

I had the same thought Friday night when I installed my PIAA's. A little whiter but not much brighter. I'm accustomed to a big difference going from 60watt hibeam to a 100watt highbeam. So I ordered a harness to see if that helps, if not I'll go to an 80/100 true wattage bulb, not "performs like"...and only draws... This should be fine with the new harness and relays.
I'll let you know how mine turns out.

Jon aka 69mach1 :burnout:


For what it's worth I just measured the voltage drop in the driver's side headlight at highbeam. With 14.24 reading across the battery terminals and 14.0 showing on the digital voltmeter gauge in the console at 2k rpm the voltage measured across the highbeam as the wiring entered connector #1021, which is essentially the bulb socket, was only 11.68. I'm probably going to add the headlight relays from Mad Electrical to see if it makes a difference.

All of this was occasioned by my disappointment in switching to the PIAA #9007 bulbs last night. Yes, they are a little brighter but not $80.00 worth IMHO. :bandit:

[David Morton]

Have you counted how many "drops" there are between the battery and your headlamps? Count the connections.

Try this experiment, put your voltmeter leads across the battery terminal post and the wire that comes from the very clamp that is on that post. You will measure a voltage drop.

There is a voltage drop across every connection whether it is soldered or not. So if you count the one at the battery clamp, the fuse panel buss, the ignition switch, the headlamp switch, the headlamp relay, and the headlamp connector itself, you will see you are doing pretty good at 11.68 volts.

Regardless, I doubt the new relays will make any difference.

[metroplex]

I have the Painless kit and Sylvania XtraVision 9007s (which are brighter and last longer than the SilverStar 9007s, as per Sylvania). The kit did not do much as I did not have any noticeable voltage drop from the battery terminals to the headlamp socket connectors, but its significantly better than the stock Sylvania Standard 9007 / Long Life 9007 combination that Ford uses from the factory.