Headlight dedicated ground - huh?

[CJ7inNH]

I debated on adding to one of the amazing grounding threads, but thought this would throw it off form the intention.

I did all of the primary groundings that are listed in the big threads - JeepHammer.

Starter, alternator, block, tub, frame - all have dedicated grounds, and I have put in a few bolts with grounds to run more off of.

Question on the headlight ground - I thought the headlight was grounded through the mounting to the grill and that's the weak point and reason for a dedicated ground. When I pulled the headlight last night it still went on while not attached or touching the body. So how is it grounded, does it really need a dedicated ground, and if it does, where is it best to put the ground wire.

I just thought of this while driving into work and don't have the electric schematics to look at.

Thanks.

 

[ThisGuyUKnow]

So you mean you had the grill completely off the jeep, not bolted in place or anything and the lights, which are grounded to the grill were still operating?

If you are getting a solid ground I would say you don't need a strap but then again I am not a fan of extra wiring if I can help it. If you want to add a grounding strap I would say just add one that is attached to one of the fenders or the frame that you already have dedicated grounds to.

I have my negative batter cable running to the side of the block and the passenger fender. From the block I have a grounding strap at the back of the head to the fire wall and one to the frame. So far I have had no grounding issues.

 

[Torxhead]

If you attach a jumper wire from the battery negative to the black wire coming out of the back of the headlight and notice no difference when the light is on then you are fine.

 

[CJ7inNH]

Hey guys, thanks for the quick replies.

It was late, I was rushing, didn't see the ground wire coming out of the back of the headlight that is grounded to the grill. I don't get it. Everything I thought I read said the headlight was grounded from the screws mounting it to the grill - not the case.

I didn't pull the grill, just the light off of the grill since I thought that was the ground.

I ran a jumper from the neg terminal to the wire - no difference.

Have to say, I was all pumped up to see a big change with all of the dedicated grounds. I went 4 GA from the neg battery terminal to the starter, 4 GA cable from the starter to the frame. Also have a 8 GA from the neg terminal to a bolt through the fender that then goes to the alternator, and a 10 GA from the neg terminal to ground things like headlight and stuff inside the cab. NO DIFFERENCE AT ALL.

I guess the good is that I have a few good grounds now when I need to run a jumper to test things.

As always, THANK YOU for the help. This site is the best.

 

[ThisGuyUKnow]

Wow! 10 gauge to the light ground! Kinda like Using a nuke in a knife fight!

 

[IOPort51]

Can I suggest you run the light power directly from the positive terminal through Bosh relays that are controlled by the switch? The switches in the CJ are not really heavy enough for the amperage of the lights. the switch gets hot and the lights do not get full battery power.

 

[GARGOYLEJEEPER]

If you have 16g + to the lights, your 10g - is still only doing 16g work, but it will do it easier and cooler.
You have enough grounds to run all sorts of things now.

 

[PaRenegade]

Can I suggest you run the light power directly from the positive terminal through Bosh relays that are controlled by the switch? The switches in the CJ are not really heavy enough for the amperage of the lights. the switch gets hot and the lights do not get full battery power.

^^^ Bingo
The grounding threads you've seen only address the negative side of the equation. To see benefit to the headlights you also need to address the positive side of things. Think of it as plumbing for a recirculating pump. Both the supply side and the drain side need to have the same sized pipe for an even constant flow, in this case electrons instead of water. It will only flow as much as the smaller pipe allows.
The problem is the power wiring for the lighting system. Adding larger direct wiring and relays that are switched by the old wiring is what gets you the brighter lights. More power + better grounds = brighter lights.

 

[IOPort51]

and don't forget the fuses.

 

[CJ7inNH]

Once again, you guys rock!

I should have been a bit clearer in my original post. I'm not really looking to gain the extra brightness by doing this, althought that would be a plus.

What I had read while researching an alternator upgrade was that the dedicated grounds should help keep the Volts meter from dropping down too much as I turn on headlight, heater, etc.

The heater motor is the biggest drain, next to the lights. I'm thinking a dedicated ground there as well. Any other thoughts on getting the heater motor to run most efficiantly?

ThisGuy - yes! I'm considering changing my log in name to "OverKill". I tend to get a little carried away with these things. I bought a huge thing of 10 ga, so might as well use it.

Thanks.

 

[CJ7inNH]

I stand corrected!

The direct grounds have helped, at least I can tell with the headlights. Used to be if I turned on the headlights I'd watch the volts take a hard hit. Now, only a slight movement on the gage. I wish I took a real reading with a voltage meter before the grounds so that I could compare exactly the difference.

Well worth the time.

Now to get at the heater motor and ground that voltage sucker.

 

[IOPort51]

I don't suppose you tightened the alternator belt or cleaned the battery terminals?

 

[CJ7inNH]

Tighten alt belt, check. I changed out the belt recently - trying to be proactive for once. Good time trying to use a pry bar to hold the alternator in place with one hand and tighten with the other. It does seem like it may have stretched a little, so I'll take out the pry bar this weekend. Dang.

Clean the battery terminals? That's so simple, of course I... didn't do that. Double dang!

 

[IOPort51]

just looking for ways you may have already improved the voltage output.