Headlamps

[Ranger]

Just when I thought I had it all sorted out, another problem rears it's ugly head.

I HATE electrical problems and am not good at them so I turn to you guys. Put on your electricians hats.

Headlamps where working, but on the way home from a cruise night yesterday, my headlamps went out.
Pretty sure parking lights and tail lights where on.
When I hit the high beams, all 4 lamps lit.
Just went out in the garage to check them again and they are working, so it appears to be intermittent.
Based on this information, where do you guys think the problem lies?

 

[droptop]

Where 90% of all electrical problems are on these cars....at the bulk head.

 

[quikbird]

think new wiring harness and bypass all that garbage.

 

[moparmonk]

I would try the dimmer switch. If you had no lights, then you had high beam, you obviously had to push the dimmer to get back to low beam. Electrical is just plumbing, but with wires. At the dimmer switch, 12 volts goes in one wire then out one of the two other wires. One of the out feeds the high and one feeds the low pending the position of the switch. Pick yourself up a free voltmeter at Harbor Freight and measure the voltage. (red lead on the output, black lead on a known good ground) A test light can light but does not give you the best indication because you could have weak or low voltage contributing to your problem. If a switch does not solve your problem, follow the wiring (as mentioned) through the bulk head and outward bound to the lights themselves. Off memory, the ground for the lights are 14 gauge size black wires near the headlights themselves. One thing is for sure, the feed to the dimmer switch is good as the high beams light. Let us know what you find!

 

[Ranger]

I have a DVM (never heard of free ones at HF). I'll check it out tomorrow, but not sure I am following you and worse yet, the problem does not now exist. Low & high beams are working properly. It corrected itself overnight. Perhaps that is somewhat of a clue.

So, if I read you correctly, I should have 12v on the supply wire (only with lights on) and 12v on the output wire going to the low beams and then 12v on both output wires when in high beam mode, correct?

 

[Basketcase]

second on the dimmer switch.pull it off the floor and turn it upside down and hit it with some penetrating oil and work the switch. usually cures the problem for me.

 

[Big John]

I'm betting on the dimmer switch too. Very common issue with these cars and the symptoms are exactly as you have said. I replaced a bunch of them back when I used these cars as daily drivers.

 

[Ranger]

I pulled it today, but all found was the mounting bolts were loose. Good to hear such a great consensus. I'll pull it again tomorrow and hit it with a shot of Deoxit.

 

[george68hemirr]

while you are at it.....upgrade to relays ....14 volts to headlites.....like night and day

 

[Ranger]

Oh boy, now you are really pushing my electrical skills George.
Can you explain the night & day difference and where these relays would go and what to buy?

So I pulled the dimmer switch. Sprayed it down as best I could to get the Deoxit inside, drained it, blew it out and reinstalled it, but I did notice something interesting. One side of the connector was slightly deformed as if it had over heated. I suspected that may have been from when it was overcharging, but I never used the headlamps during that time. Now that said, having just purchased it in Dec. and having just installed the voltage gauge, I have no real idea just how long it was overcharging. Guess I'll just have to see if it happens again and if so, I think I may know where I'll look first.

 

[Basketcase]

get'm a couple cases of beer and maybe he'll do it for you!:jester:

 

[Ranger]

If he makes house calls, I'll have the beer.

 

[quikbird]

Daniel stern lighting has a lot of good info on his website on how to upgrade headlights with relays etc. will post a picture on how I did mine tomorrow.

 

[george68hemirr]

Oh boy, now you are really pushing my electrical skills George.
Can you explain the night & day difference and where these relays would go and what to buy?

So I pulled the dimmer switch. Sprayed it down as best I could to get the Deoxit inside, drained it, blew it out and reinstalled it, but I did notice something interesting. One side of the connector was slightly deformed as if it had over heated. I suspected that may have been from when it was overcharging, but I never used the headlamps during that time. Now that said, having just purchased it in Dec. and having just installed the voltage gauge, I have no real idea just how long it was overcharging. Guess I'll just have to see if it happens again and if so, I think I may know where I'll look first.

night and day.....no more dimming of your headlites while idling......your headlites will be nice and bright....there will be one relay for low beam and one relay for high beam....if you look at diagram it shows you that....very simple hook up

 

[Ranger]

Thanks for the info Quickbird. The Daniel Stern site explaines it so even I can understand it.
I don't expect to be doing too much night driving, but I bookmarked the site and will keep it in mind as a future upgrade if needed. I appreciate the great advice. :worship:

 

[quikbird]

here is the photo of my layout. as George said, not too complicated. :huh:

 

[Ranger]

Just got back from a local cruise night. Drove all the way home with lights on and they worked perfectly. :noidea: Maybe it was just a bad (old) connection at the connector. Time will tell.

 

[OutLawBiker]

HI,
AFTER READING THIS THREAD I AM COMPELED TO ASK A QUESTION CONCERNING MY 73 RR.
I JUST INSTALLED A PAINLESS WIRING HARNESS # 101427 21 CIRCUIT. I NEED TO KNOW ON THE HEADLIGHT SWITCH WHAT WIRES GOES TO WHICH OF 7 MALE CONNECTORS. THE PLASTIC HOUSING FOR THE SWITCH IS NO LONGER.
PLEASE HELP...
PS I HAVE THE RALLY PACKAGE.

 

[quikbird]

Are you using the original switch?

 

[quikbird]

There are some diagrams online for the switch. It shows 8 wires on 6 posts
2 yellows go to door switch and map light, dome etc
Pink is other lights
Light green beam selector switch
Tan park lights
Black yellow tracer. Light relay
That’s not all of them but should be a start