Under hood LED light battery question

[dergibog]

I have a question about the battery. Specifically the positive battery terminal.
I bought this-
http://m.ebay.com/itm/Under-Hood-LE...hicle-White-/301651870915?txnId=1178050980020
It's great, but when I went to attach the positive wire I get confused.
When you take the cap off the terminal, you'll notice like, 3 or 4 sub posts posts, all but one in use. So I thought that would be perfect spot to attach the ring terminal to. I'm not getting any power to it. Very strange because I get power to all the others. Also, looks like a fuse installed in the sub post splitter but it's not blown. So, I'm confused. Anyone know what I'm missing?

 

[MikeM.]

Anyone know what I'm missing?

Sounds like you're missing a multi-meter.

 

[dergibog]

Nobody?

 

[starmagic]

Its either a defective product or you installed it wrong.

 

[dergibog]

All the other posts work except for the far left one. The product is great & works perfectly! Just don't know why the far left terminal post isn't putting out any juice. Anyone be willing to test theirs & share results? It would be most appreciated.

 

[minnesotaart]

All the other posts work except for the far left one. The product is great & works perfectly! Just don't know why the far left terminal post isn't putting out any juice. Anyone be willing to test theirs & share results? It would be most appreciated.

OK, I found some time to test this out today with my multi-meter. I had power to all four places. BUT on the 4th (far left one - the one you are trying to use), when you measure for voltage just at/on the post, there is NO voltage. If you look real closely you'll see a shiny sliver of metal that appears like a u-shaped fork around the bottom of the post. THIS is where the juice is, not on the post! Look at the other 3 connections and you'll see that the Mazda connectors on the end of the wires are specially made to make contact with that shiny metal. And, after they do, THEN if you test for voltage at the post you will get it (there is voltage on the 3 used subposts measured at the post). So, to recap, you need to make contact with that shiny metal part in order to get any juice. Perhaps a conductive metal washer over the post before your light's connector might do the trick? Also, each one of the connection spots has a fuse underneath some clear plastic on the battery side of the subpost array (for lack of a better term), so be sure the fuse isn't blown. I don't really know more than that, I'm a rank amateur at auto electric, but thought I'd try and help you out.

 

[dergibog]

Sweet. Thanks for the tip! I'll try it and report back. I didn't place my multimeter where you are referring to.

 

[yrwei52]

If you look real closely you'll see a shiny sliver of metal that appears like a u-shaped fork around the bottom of the post. THIS is where the juice is, not on the post!

Good find and nice to know! Thanks for telling us and I may miss this even if I'm using a multimeter too ...

 

[dergibog]

Bingo. That was it. Threw on a small washer to help make contact to that metal sliver & a nut. Works like a charm. Thanks a bunch minnestotaart.

 

[yrwei52]

Threw on a small washer to help make contact to that metal sliver & a nut.

Are you using a cooper washer for better conductivity?

 

[dergibog]

No. Think I should? It's only an led light. Worth it?

 

[ryan4130]

Not worth it. LED light uses considerably low amperage. Also, not to be an a-hole but I agree with the other poster.... Get a multimeter. They can be bought cheap at harbor freight or online and they really really come in handy. Btw the engine compartment lighting looks like a good idea!

 

[brillo54]

No. Think I should? It's only an led light. Worth it?

Nope. Stick with a washer that is less prone to corrode or oxidize. What you used is fine.

 

[GP 2004]

Not worth it. LED light uses considerably low amperage. Also, not to be an a-hole but I agree with the other poster.... Get a multimeter. They can be bought cheap at harbor freight or online and they really really come in handy. Btw the engine compartment lighting looks like a good idea!

Look in the back ads in magazines like Field & Stream, Car & Driver and Motor Trend. I was at the dentist to get my teeth cleaned recently and while waiting I remember seeing the Harbor Freight ad which had a coupon for a free multimeter. I can't remember which magazine though.

 

[MikeM.]

Look in the back ads in magazines like Field & Stream, Car & Driver and Motor Trend. I was at the dentist to get my teeth cleaned recently and while waiting I remember seeing the Harbor Freight ad which had a coupon for a free multimeter. I can't remember which magazine though.

Free multi-meters are worth about what you pay for them. They drift over time as their cheap capacitors and other components degrade rather rapidly.

 

[Kedis82ZE8]

The free ones are good for some limited tests for voltage and continuity.

I have some nice Fluke meters for electronics projects but keep the cheap HFs scattered in drawers when I need one for some quick tests.

EDIT: I do agree about capacitors... one of the biggest reasons for electronics failures these days. I've fixed so many things over the years for a $0.50 component.

 

[dergibog]

Guys. Please reread. I did use a multimeter. Thanks for the advice though.

 

[ryan4130]

We just love multimeters!!!!!

 

[dergibog]

Lol!

 

[yrwei52]

Post #7:

Sweet. Thanks for the tip! I'll try it and report back. I didn't place my multimeter where you are referring to.

Post #8:

Good find and nice to know! Thanks for telling us and I may miss this even if I'm using a multimeter too ...

Guys. Please reread. I did use a multimeter. Thanks for the advice though.

LOL... People just assume things early and not really reading through all the posts before posting the reply...

BTW, I'd get a cheap cooper washer from Home Depot as using metal washer for electrical current just doesn't seem right to me. It may easily cause corrosion at contact point between different metals with electrical current going through ...