wiring problem with LED's

[dickfoster]

But.... It's the circuitry associated with the LED's that is polarity sensative.

LEDs are typically wired in series for voltage distribution and if there is anything to limit current it's usually a resistive device. You'd almost have to go out of your way to make it polarity sensitive to where damage would occur if you hooked it up bassackwards.

 

[5030]

I guess (maybe) we will find out if he cooked it or not..........

 

[buickanddeere]

Just so you know. LEDs are diodes so they have their own inherent reverse polarity protection built in. Diodes only allow current to flow in one direction so if you hook them up backwards they just don't work but no current flows so no damage. To cook them you have to exceed the voltage rating and allow too much current to flow, then they will live for only one brief shining moment and shine no more.

Didn't protect the LED's that we purposely reversed during lab class in college.

 

[budepps3760]

Here are 2 pictures that I took of the wiring diagram from the case of the relay. I brought the tractor in to charge it. Sanded a few areas to try and get a better ground location but still no luck. I can't direct wire to the battery as I would have to open the bar up to gain access to wire to clip onto and thus my warranty would be gone at that point. Going to take the battery up in the next couple of days to see if that helps and also to see if I can find a method of direct wiring before I send it back to the manufacturer. Lifetime warranty and so might as well take advantage of it if I can't scratch my hnead and figure something out.

 

[Xfaxman]

Did this come as a complete unit including the lighted switch?

Any instructions?

 

[budepps3760]

Yes came as a unit with wiring harness already connected. The instructions basically said to hook red to positive and black to negative.

 

[Xfaxman]

So I guess you added longer wires.

Did you run the positive through a fuse?

It should be easy to find the problem with a multimeter.

 

[hosspuller]

Looks to me from the diagram, that the relay is a normally on. When you energize the relay it opens the contact. So turn on the relay, no power to light bar. Yet the light bar is off because the switch is off.

 

[Xfaxman]

Yep, I noticed that also, so I googled the part number and it showed a normally open 5 pin relay.

So either the diagram or the part number is wrong.

It is a standard automotive relay and pin 87 is NO, 87a is NC.

There is also a 4 pin version:

 

[budepps3760]

I pulled the cap off the relay and it is a 4 pin relay and not a5 pin. Yes I did run longer wires and the red wire does have a fuse in it.

Just so happens I bought a Klein Tools 1000 mm multimeter last week as I needed to check the capacitors on a phase shifter that was used for dad's 3 phase equipment I his cabinet shop. I have limited knowledge on electrical circuits so what is your recommendation in going about checking the relay? Walk me through the process and I will test Tuesday when I return to the farm with the tractor battery recharged.