Riddle Me This Batman......Voltage Drop at light switch....

[Htownblue]

Scenario: 2015 CC Precedent. Standard LED light kit. 20 amp 48v reducer.
Symptom: front LED lights are dimmer than normal.
12.4v show at “hot” yellow wire from harness.
Load yellow wire shows 10.2 AFTER switch is activated.
I’ve tried two separate light switches. One manual and one LED. Both show 10.22 v going to front headlights when activated.
Tried two harnesses.
Tested 12.4 volts at reducer and fuse Buss.
12.2 Volts at light harness input wire.
Post switch voltage at headlight to harness connection is also 10.22.

Also I have two sets of spot LED’s that appear to function normally when switched on. As well as a stereo that functions normally.

What would cause a voltage drop at the lights on/off switch? And is this normal. And would a 2 volt drop be enough to cause my front LED’s to be dim?

I think I know the answers to some of the above but I am at a loss as to how to get my front LED’s functioning again like normal.

What sayeth the mighty Buggie Mob Brain Trust? I beseech thee....

[ThreeCW]

Why not try a jumper wire to put 12.4 volts directly to the lights to see if they perform to your satisfaction (and also check the voltage using with the 12.4 volt wire connected).

Brainstorming ... could it be a ground issue? Might be something to check.

Normally LED lights work over quite a large voltage range. Are these factory installed lights or aftermarket?

[Htownblue]

Originally Posted by ThreeCW

Why not try a jumper wire to put 12.4 volts directly to the lights to see if they perform to your satisfaction (and also check the voltage using with the 12.4 volt wire connected).

Brainstorming ... could it be a ground issue? Might be something to check.

Normally LED lights work over quite a large voltage range. Are these factory installed lights or aftermarket?

Did the aforementioned. They lit up pretty dang well with 12v direct to the headlights. This is an LED front headlight kit I bought from Dave a long time ago.
I suppose it could be a ground issue but the ground from the harness is seemingly ran correct to the fuse Buss ground terminals etc.

[ThreeCW]

If the lights lit up good with the 12.4 volt jumper and you were using the factory wiring harness for the ground, then the wiring harness ground would be fully functional.

If that is the case, the factory 12.4 volt wire may be the culprit.

Did you jumper both lights together or one at a time? To eliminate doubt you should repeat with both together and if it works (using the factory ground), you should consider running a new 12.4 volt wire to run your lights.

Try wiring the light switch into the 12.4 volt jumper wire circuit to see if you get the same results.

If you decide to run a new 12.4 volt wire to your lights, you will need to make sure it is fuse protected either from your fuse block or an inline fuse.