2 problems: one with headlights. second with turn signals [Archive] - Chevelle Tech

: 2 problems: one with headlights. second with turn signals


71chevelless05
Mar 18th, 10, 12:39 AM
Its a 1971 chevelle malibue 2 door hardtop. the problems: whenever i step on the breaks my parking lamps and dash lights come on and only the left turn signal would work; right one just stays lit. Had my mechanic check it out, now the turn signals work but the parking lights n dash lights still light up. But if you turn the headlights on the turnsignals quit working.

second problem: when my head lights are on while driving at night you can visibly see the lights get dim and then bright for the most part its constant. I have replaced the alternater twice already and it has a new batter.

Hopefully someonebody can help because i am out of ideas.

undee70ss
Mar 18th, 10, 3:56 AM
Its a 1971 chevelle malibue 2 door hardtop. the problems: whenever i step on the breaks my parking lamps and dash lights come on and only the left turn signal would work; right one just stays lit. Had my mechanic check it out, now the turn signals work but the parking lights n dash lights still light up. But if you turn the headlights on the turnsignals quit working.
Your problem is most likely at the right rear tail light. First, be sure you have the correct bulb in, it should be a 2 filament. A single filament bulb can cause this problem. Be sure the 2 contacts at bottom of socket are not touching each other. Be sure the socket is wired correctly, and has a good ground. A poor or missing ground also causes this.


second problem: when my head lights are on while driving at night you can visibly see the lights get dim and then bright for the most part its constant. I have replaced the alternator twice already and it has a new batter.
With the original externally regulated charging system, this is normal. It is probably most noticeable at idle. Mechanical voltage regulators have a set of points (much like the points in a original dizzy) that open and close rapidly, constantly adjusting the voltage. Original type alternators also have low output at idle and slow engine speeds and just adds to the problem. If the GEN lamp is not coming on (assuming its working correctly) its really nothing to worry about.

If the bright/dim bothers you, you can try replacing the voltage regulator with a solid state one, but the real fix is to convert to a modern internally regulated alternator.

Robinls5
Mar 18th, 10, 7:58 AM
Something else to consider. If a bulb has a broken filiment and the filiment is laying down on the other filiment inside the bulb. This broken filiment on the stop light bulb will backfeed and could cause the parking lights to light up when you hit the brakes. Just something else to put on your checklist.
Bob

71chevelless05
Mar 18th, 10, 10:34 PM
thanks for the info.. i ll check the rear turn signal out tmrw. i let you know how it goes

71chevelless05
Mar 18th, 10, 11:03 PM
could it be my hazard light switch/turn signal. cus that one problem when i hit the breaks my parking lamps come on and my dash lights come on

undee70ss
Mar 19th, 10, 5:34 AM
No. The only point where the 3 circuits meet is the rear parking lights. The brake lights are grounding through the parking/dash lights.

71chevelless05
Mar 19th, 10, 11:16 AM
k i checked all the bulbs on the right side this morning.. all the bulbs are ok. there sockets are goodand the ground wires are good. any other ideas on what the problem is. the right turn signals work when the headlights are off, turrn headlights off right turn signal quits working but the left works. is it also normal to not have the hazard lights work if my foot is on the break?

undee70ss
Mar 20th, 10, 2:40 AM
the right turn signals work when the headlights are off, turrn headlights off right turn signal quits working but the left works.
????
any other ideas on what the problem is.
Test......... take a piece of wire, several feet long. Strip about 1/2 of a inch of insulation off one end and put it in between the bulb and socket (do not put it in to far, you just want to make good contact with the metal ground side of the bulb). take the other end of wire and bolt it to a clean bare metal ground. Test you lights again.

is it also normal to not have the hazard lights work if my foot is on the break?

Yes

71chevelless05
Mar 20th, 10, 3:43 AM
alright heres another problem to add in... alternater went out on me at 3am this morning,left me sitting. also update hazards dont flash at all they just stay lit up. and to clarify the turn signal problem. headlights off: turn signals work, hit brakes the dash lights come on, hazards just stay lit. headlights on: left signal works, right stays lit, hazards dont work.

RealRed70
Mar 20th, 10, 7:04 PM
I had similiar problems in the past. Sounds like a short to me. Once my gauges would not work when headlight swich was in on position. Turn lights off and everything was fine. I replaced the headlight switch then all was good. Once I had a bad printed curcuit board and it caused problems with my directional lights on dash staying lit and not blinking. Also gave me trouble with my hazards. I changed the flashers and that did not help, checked all grounds that did not help. Finally after hours of fooling around I dropped the dash and put in a different printed curcuit and all was good. Just some things to try or think about. Good luck as these problems are time consuming and very frustrating. Sometimes one just needs to take a break and just slow down and think about it, before the hammer comes out.

Shadowpit
Mar 22nd, 10, 3:48 AM
This sounds like what I just went through. My car wouldnt even start anymore unless I jumped it I thought it was the alternator, then the battery. The lights were funky too. I would turn on the headlights and it was stuck on high beams, blinkers would blink slow or not at all. When I hit the brake the dashlights would come on and yeah my high beams dim in and out and if I hit the floor switch it would make my headlights blink. I bought a wiring diagram for my car and pulled just about everything and rewired it all. I found some crap wires and some that were not hooked up right and some that werent hooked up at all and some that were just grounding out on metal. I fixed my wiring and after that she starts up everytime like a champ and the lights work and I had lights in places I didnt know I had lights lol, just feels better. I did have to replace the high beam switch though. Anyways it sounds like what I just went through so just a thought before you go and do what I did and buy a new alt and all that stuff.

NetDisruptor
Mar 24th, 10, 4:26 PM
Just to add this for anyone else checking this thread.
If the switch for the head lights get's a bit loose it can twist and short out and cause all kinds of strange things. When this happened to me my head lights would turn on and I was 20 feet from the car, it only lasted a few seconds and seem to only do it 15 to 20 min's after I drove it. also dash lights and head light would get dim and bright when in use.
After I figured it out and fixed it all was fine.
It did freak some people out though.

71chevelless05
Mar 26th, 10, 12:14 AM
alright fixed part of my problem. i had to put a new alternator charge my battery and found out i had to rplace my voltage regulator. headlights are good now n battery doesnt drain. still have my turn signal hazard light problems though. could it be a switch that is bad because everything was fine n then one day bam just started doing it.

71chevelless05
Apr 12th, 10, 12:56 AM
K another thing to add to the list of electrical problems.. when i drive with my headlights off my tach doesnt read right, but heres the thing it doesnt do this constantly. if the headlights are on it doesnt do it as much. also i still have the turn signal, parking light, hazard light, and dash light problem... so many headaches

whitebrother
Apr 13th, 10, 11:03 PM
I had a goofy problem with the lights on my 72 El Camino. My headlights would flash on and off when I turned the turn signal on. Come to find out that behind the battery where the headlight wiring is there was a ground wire frayed and grounding out on who knows what??? Replaced the broken wire and no more problem. You can not see the wires without removing that battery.