MY HEADLIGHTS DONT WORK ???

[Mopar Tom]

How come nobody ask him to check for continuity in the fusible link
Or has someone asked you & I missed it ?--------------------Mopar ToM
Or where does your headlight circuit get its power

[satellite65]

Gets it from through the fusible link but then again, so does everything else. If the F.L. let go he would have no power to anything. I'm not a big fan of "hunt and peck" or "try this and try that" troublshooting. He needs to take a systematic aproach and once he does, he'll find his problem.

Southtex, you need 2 things. The wiring diagram and like NYrr496 said, a digital multimeter. It doesn't need to be a fancy or expensive one, any cheap Radio Shack or Home Depot job will do the trick.

[south tex mopar]

First and foremost, you need a digital multimeter.  Once you start probing and learning where power is and isn't, this becomes very simple.

So a simple test light wont work? How am i to know, how much voltage each wire is suppost to have anyway, thats what that device is for right?

[south tex mopar]

I copied  the wiring diagram off of the mymopar site. Also when i took the wiring out of the duster, I labeled all the wires before removing them. So could the switch on the floorboard be bad, and that stop the headlights to work. I see the fusible link that you mentioned is in the middle port on the bulkhead. Seems all the lights are thru that bulk head, so why the hell is it called a fusible link if theres no fuse in it??? Makes no sense  

[satellite65]

It's a piece of wire thats designed to burn open at a specified temperature relavent to current. It's a throwaway item. Once it cooks, it goes in the garbage and gets replaced.

[MoPar_or _NoCar]

Take the test light and verify power @ fuseblock. No power switch is bad or no supply to it, we'll go into that later. It will only light up when switch is on. Next verify power @ light socket. If you have power it's either bulb or ground. Get a multimeter anyways in case you need to find the open circuit.

[south tex mopar]

It's a piece of wire thats designed to burn open at a specified temperature relavent to current. It's a throwaway item. Once it cooks, it goes in the garbage and gets replaced.

Specified temperature relavent to current??? Burn open??? I could swear you where speaking chinese just now. No idea what that means but, Ok, So how the hell can i tell if its good or not?

[MoPar_or _NoCar]

It's a big fuse. A mutimeter will check the continuity across it. It is good if everything else is working.

[satellite65]

If your car runs, the fusible link is O.K.

I don't think there's anything wrong with your fusible link. I think that once you start tearing into this you're goint ot find either:

A- Bad headlight switch
B- Bad headlight dimmer (the pushbutton on the floor for the brights)
C- Bad ground
D- Any combination of the above

Also, this is a very good, simplified explanation of how a Mopar charging circuit works. Look at the wiring diagram and you'll see exactly what the fusible link is doing. Click the link below.

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

[south tex mopar]

Satellite65, I read the article,  it was very helpful, thank you. Another thing worth mentioning, is that i need to leave the battery disconnected henever im not using the car. If i leave it hooked up,any amount of time with the car off,it kills the battery. What do you think?? Part of the same problem???

[MoPar_or _NoCar]

Something is on or grounding. Disconnect the battery cable, as you reattach it will arch. Pull fuses one by one til it stops and there's you culprit.

[satellite65]

Could be. You got something drawing power when it's not supposed to. The way to check for that is to put an ammeter ( function of a digital multimeter-you REALLY should have one) between the negative battery terminal and the negative battery cable. You'll see a reading on the meter. Disconnect different items or pull fuses one at a time until the current reading goes to zero. You have a short someplace, maybe not a dead short but just enought to cause a drain on your battery.

[south tex mopar]

Something is on or grounding.

I am going to try that setup on the link satellite65 put up. all though i dont see how that will solve my headlight problem, it seems to be better than running the charging setup our mopars have as stock. I put a test light to the headlight connections and they have no power.

[MoPar_or _NoCar]

Do you have power @ the fuse block with switch pulled on?

[satellite65]

Something is on or grounding.

I am going to try that setup on the link satellite65 put up. all though i dont see how that will solve my headlight problem, it seems to be better than running the charging setup our mopars have as stock. I put a test light to the headlight connections and they have no power.

Fix your real problem first. Don't open up a can of worms by trying to modify the system.

[MoPar_or _NoCar]

 
http://cgi.ebay.com/FLUKE-MODEL-77-AN-MULTIMETER-w-PROBES-TEST-METER_W0QQitemZ120305242809QQihZ002QQcategoryZ58277QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[south tex mopar]

I didnt get around to checking that one today, do i check it at the fuse terminal or at the wire? It doesnt matter right? If  at the wire do you know what color wire it is? So i dont have to go looking for it.

[satellite65]

The modification is NOT going to solve your headlight problem. I only posted it to explain what the fusible links purpose is.

[MoPar_or _NoCar]

Check the fuse itself, it will only be hot when on since the power is fed from switch. The diagram should give you color orientation on wire side of block. I think it's the second from left fuse?

[south tex mopar]

The modification is NOT going to solve your headlight problem. I only posted it to explain what the fusible links purpose is.

Yea i didnt think it would solve the problem, it would be something to do after i fix this problem first. Im going outside to check if theres current at the fuse terminal. Be right back

[satellite65]

Listen man........... it's 1:15 here in NY. I gotta go to sleep. I'll check back with ya tomorrow.

Later,

Steve

[south tex mopar]

Yea its late but i dont have anything better to be doing, plus im always so busy at work during the day . Sooo, i checked the fuse that is labeled lps and another thats labeled lp, and they have no power with the light switch pulled back

[south tex mopar]

Something is on or grounding. Disconnect the battery cable, as you reattach it will arch. Pull fuses one by one til it stops and there's you culprit.

What do you mean by it will arch?

[MoPar_or _NoCar]

Something is on or grounding. Disconnect the battery cable, as you reattach it will arch. Pull fuses one by one til it stops and there's you culprit.

What do you mean by it will arch?

When removing or replacing the battery cable, look @ it close and you will see a little spark.  Sounds like bad switch or no supply to it. Remove switch and check for power to it via diagram, and check continuity for the switch. What year is the car?

[south tex mopar]

Mopar or no car.  Mines a 72. Actually it doesnt spark when taking off or putting on the battery. Right now im in my living room with the headlight harness off of my car and the underdash harness off of a 73 duster. Have the wiring diagram out, and i traced the headlight harness onto paper beacuase it is less confusing than looking at the whole diagram. I switched the high beam low beam button on the floor, with no resolve to the problem. There was no power to anything in the light harness. In an hour or two i should have the harness back on. Ill post my results.

[south tex mopar]

Whats up with the printed circuit connct. Theres 1 red wire and a lt green wire that go to it.

[MoPar_or _NoCar]

That's your dashlights. Theres a primitive circuit board on the backside of your instrument cluster.

[south tex mopar]

That's your dashlights. Theres a primitive circuit board on the backside of your instrument cluster.

ok thanks man i would have spent an hour looking for it probly.

[south tex mopar]

Ok so my headlights work and the car still runs. They were 2 frayed wires in the harness. Man it was alot of work, started at 11 am and didnt get done till 8 oclock at night. As always you guys are awesome, i can never thanks you guys enough. 

[satellite65]

Glad you got it working. The frayed wires were probably touching each other or ground slightly. If one of them was the power feed to the headlight circuit that may be what's causing your battery to drain when the car is off.