what is wrong with my lights

[Mr.720]

My headlights never work right. Either the two driver side lights work and the other two dont, or the two driver side lights work and only one of the passenger lights work and my brights indicator is always on. I replaced the relay but that did nothing. What else could it be?

[izzo]

That is strange.  Don't touch anything..., look inside at the wires running off the lights.. See any bare?  Maybe turn the lights on and wiggle the wires and see if it pops on.

 

Turn the lights on and run a multimeter... test the plugs, see if there is juice to the wires at least... If not, then the problem is somewhere else.  If there is power at the plugs but not lights, then its probably the corrosion inside the plugs.

[Mr.720]

Sweet. Thanks man

[izzo]

Report back with what you find.. Simple free check you can do just to see if its at the plug end or not.

 

 

My 80 720, low lights there were two lights on... High beams, all 4 were on.  I had an 86 St, low beams were two lights, high beams there were only 2 lights on. I thought something was wrong, someone else told me it was normal  Thought it was strange....  Not what you are experiencing tho.

[Mr.720]

Yup. ill let you know

[datzenmike]

Check both headlight fuses. They are on the far right side of the fuse box. I suspect the very far right one is blown but check both. By check, I do mean replace them, as they cannot be trusted simply by looking at them

[Z-train]

Stupid problems in electrical systems are almost always a ground issue.

[filthy forever]

check available voltage to your headlights, its a parallel circuit so there should be battery voltage. if not, do a voltage drop on either the power or ground side of the circuit.

[wayno]

The 720 wiring harness is a strange animal, if a ground isn't working correctly, stuff don't work, and if you add a ground in the wrong place, they don't work right then either.

Did you add fog lights?

If you grabbed power from anywhere in the headlight circuit, it will mess things up, did you add aftermarket gauges and try to wire in the gauge lights to your headlight circuit?

Any wire that is added to the headlight circuit of the wiring harness can screw things up.

You still have square headlights, correct?

[Mr.720]

Yes i still have square headlights But I havent added any gauges or fogs or anything. i have never messed with my Wiresd at al

[datzenmike]

Check both headlight fuses. They are on the far right side of the fuse box. I suspect the very far right one is blown but check both. By check, I do mean replace them, as they cannot be trusted simply by looking at them

.

This is easier and faster.