Spyder headlamps.....my take on 'em...and LIGHTING in general

[shovelbill]

started today with truck off and a battery voltage test....12.1V. i forgot to put it on a charger last night!

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with the low beam lit the voltage was.....

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negative side....11.5v

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EDIT:
positive....12.1v-9.6v=2.5v
negative...12.1v-11.5v=.6v

2.5v+.6v=3.1v total voltage drop on this circuit....with what we are working with here
12.1v-3.1v=9v
the bulb is seeing 9 Volts in this example..

and again....michael hurd corrected me and directed me to the proper way to do this voltage drop test.

 

[shovelbill]

high beam

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the ground was the same 11.5v

EDIT:
the voltage drop on the high beam circuit is 3.5 volts

 

[shovelbill]

truck idling....14.7.....stock headlight harness. correct testing through the bulb

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checked ground...the meter was bouncing betwixt 14.4 aand 14.5

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and like yesterday i checked the plug again....this time through the lit low beam

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high beam lit...positive

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checked the ground at the lit high beam lamp....14.3v

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EDIT:
14.7-12=2.7
14.5-14.3=.2
14.7-2.9=11.8
the bulb is seeing 11.8 volts with the truck running, through the factory harness.

 

[shovelbill]

i temporarily screwed in the right side ground from the harness.....yes, i ran the harness through the radiator support......most of the harness will be in front of it......there's too much **** under the hood to make it reasonably clean.....EDIT: the truck was off.

at the battery

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at the harness ground....they're the same....call it good.

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[shovelbill]

again...this is semi-temporary....i want to change the battery terminals and i need the proper connector for the end of the 10G positive wire for the entire harness.

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i wanted the fuse next next to the relays, but it will be cleaner this way because the positive will have a clean short run riht to the battery positive.

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i left the length till i'm sure what i want to do

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[shovelbill]

truck off again...11.5v at the battery

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truck off and a check at the new low beam connector....11.5v....NEW HARNESS

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truck off....high beam 11.5.....NEW HARNESS

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EDIT: even though the truck battery is very low voltage @ 11.5....it shows there is no voltage drop through the HARNESS and RELAYS......

 

[shovelbill]

be back in a while.....have some things to do

 

[michael hurd]

Doing the math just for the low beam, I get 3.1V drop, off of your unloaded voltage.

14.7 - 3.1 = 11.6V.

The factory ground has less drop, but still enough to lower the brightness.

 

[shovelbill]

i was just going back....i think i have some pictures wrong......damn

 

[shovelbill]

Doing the math just for the low beam, I get 3.1V drop, off of your unloaded voltage.

14.7 - 3.1 = 11.6V.

The factory ground has less drop, but still enough to lower the brightness.

i think i screwed up some pictures
what's the voltage drop math for post 351? that was stock harness new bulbs

post #353 is correct

i fixed post #354

but yes, we have 11.6 volts through the stock harness. that's what the bulb is seeing.