I'm trying to sort out some irregularities in my front turn signals and markers on my 1972 super that appeared just after I had it in the paint shop. It's going back to the same mechanic who did the body work and reassembly on Friday, but I wanted to post here what the symptoms are and see if anyone here can tell me where the two of us should start looking. I've already wasted many hours trying to sort this out on my own and definitely have decided professional help is in everyone's best interest. the first thing I did was reground the assemblies with new wires spliced in to the original harness.
Driver's side
Side marker bulb is on, seems OK
Front bulb / front taller filament is on
Turn signal: side bulb and front bulb / front taller filament blink in unison
Everything looks dimmer than you would expect, maybe just because the other side is so bright
No signs of life from the front bulb / rear shorter filament
Rear turn signal quick flashes
Passenger side
Side marker bulb is on, dim, hard to tell it's on until you remove the lens
Front bulb / rear shorter filament is on very bright
Turn signal on: nothing blinks on front assembly
No signs of life from the front bulb / front taller filament, either flashing or on steady. It is never on.
Rear turn signal rapidly flashes (even faster than driver's side)
Front marker / turn signal foolishness
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KarenTheBug
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Front marker / turn signal foolishness
Since 1938, it's what the People want.
1971 Type 1 model 1300 Sedan
1972 Type 1 model 1302 Sedan
1971 Type 1 model 1300 Sedan
1972 Type 1 model 1302 Sedan
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Marc
- Moderator
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- Joined: Thu May 23, 2002 12:01 am
Re: Front marker / turn signal foolishness
On the driver's side you apparently still have a ground issue. Either the ground's just no good or the wires are scrambled.
Without a ground to the shell of the bulb, the dim/tall filament and the bright/short filament end up effectively in series, and the ground path for the parking light power ends up via the rear t'signal filament....the brighter filaments don't drop as much voltage so they don't glow, and all you see working is the dim filament. Since the little sidemarker lamp is in parallel with the dim/tall one in the large bulb, it also grounds through that path.
On the passenger side I'd start by verifying that all the connections are correct, can't tell from here precisely what the issue is.
Note that there are inline connectors inside the trunk for the t'signals and parking lamps; normally there's no need to disturb these but one never knows what may happen to wiring once inside a body shop. Something about the artistic temperament possessed by good body/paint people that seems to prevent them from understanding the logic of simple electrical circuitry
Color code: Ground wires are brown. Parking light wires are gray to the large bulbs, the light-gauge wire going from there to the sidemarker bulb is black.
Left t'signal is black with a white stripe; Right t'signal is black with a green stripe.
BTW, unless someone's changed things at the fusepanel. the last fuse powers BOTH front parking lamps & marker lamps, as well as the right tail lamp and the license plate lamp (six filaments in total) while the fuse next to it powers only the left tail lamp. Don't have any explanation for such lousy load distribution (the same basic light setup existed in 1970 with a more balanced arrangement) but that's the way it is on `71-up cars.
Without a ground to the shell of the bulb, the dim/tall filament and the bright/short filament end up effectively in series, and the ground path for the parking light power ends up via the rear t'signal filament....the brighter filaments don't drop as much voltage so they don't glow, and all you see working is the dim filament. Since the little sidemarker lamp is in parallel with the dim/tall one in the large bulb, it also grounds through that path.
On the passenger side I'd start by verifying that all the connections are correct, can't tell from here precisely what the issue is.
Note that there are inline connectors inside the trunk for the t'signals and parking lamps; normally there's no need to disturb these but one never knows what may happen to wiring once inside a body shop. Something about the artistic temperament possessed by good body/paint people that seems to prevent them from understanding the logic of simple electrical circuitry
Color code: Ground wires are brown. Parking light wires are gray to the large bulbs, the light-gauge wire going from there to the sidemarker bulb is black.
Left t'signal is black with a white stripe; Right t'signal is black with a green stripe.
BTW, unless someone's changed things at the fusepanel. the last fuse powers BOTH front parking lamps & marker lamps, as well as the right tail lamp and the license plate lamp (six filaments in total) while the fuse next to it powers only the left tail lamp. Don't have any explanation for such lousy load distribution (the same basic light setup existed in 1970 with a more balanced arrangement) but that's the way it is on `71-up cars.
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KarenTheBug
- Posts: 312
- Joined: Sun Aug 30, 2009 5:39 pm
Re: Front marker / turn signal foolishness
So, can you explain how it should look when it works? What I'm aiming for? I may tinker more today. Basically, which filaments should glow when the headlights / running lights are on steady, which filaments should blink when the turn signal is activated, and should the filaments blink in unison or should one drop, then the other?
I definitely had a ground problem when I first got it back. The headlights also didn't work, but I fixed those by splicing new wires into the existing harness to ground them properly. Both were dimmed, one was so dim almost didn't come on at all. Now they're both uniform brightness, high and low beams. I already tried splicing a new ground wire into the existing harness for the turn signal assemblies, but it didn't help. Either the loss of continuity is elsewhere in the assembly higher up than where I spliced in the new wire, or my splice was not very good, or there's a short elsewhere.
I definitely had a ground problem when I first got it back. The headlights also didn't work, but I fixed those by splicing new wires into the existing harness to ground them properly. Both were dimmed, one was so dim almost didn't come on at all. Now they're both uniform brightness, high and low beams. I already tried splicing a new ground wire into the existing harness for the turn signal assemblies, but it didn't help. Either the loss of continuity is elsewhere in the assembly higher up than where I spliced in the new wire, or my splice was not very good, or there's a short elsewhere.
Since 1938, it's what the People want.
1971 Type 1 model 1300 Sedan
1972 Type 1 model 1302 Sedan
1971 Type 1 model 1300 Sedan
1972 Type 1 model 1302 Sedan
-
Marc
- Moderator
- Posts: 23741
- Joined: Thu May 23, 2002 12:01 am
Re: Front marker / turn signal foolishness
Condition 1. Parking lamps on: the dim/tall filament of the large bulb, and the sidemarker filament should be lit.
Condition 2. Parking lamps off/t'signal on: (a) the bright/short filament of the large bulb should be blinking...(b) no other filaments lit.
Condition 3. Parking lamps on/t'signal on: Same as Condition 1 plus Condition 2(a); there should be no interraction ("alternating").
You may discern a very slight dimming of the parking lamp filaments as the t'signal filament lights. Assuming a constant supply voltage, that indicates that the current capacity of the ground circuit is inadequate to support simultaneous operation of all filaments.
Condition 2. Parking lamps off/t'signal on: (a) the bright/short filament of the large bulb should be blinking...(b) no other filaments lit.
Condition 3. Parking lamps on/t'signal on: Same as Condition 1 plus Condition 2(a); there should be no interraction ("alternating").
You may discern a very slight dimming of the parking lamp filaments as the t'signal filament lights. Assuming a constant supply voltage, that indicates that the current capacity of the ground circuit is inadequate to support simultaneous operation of all filaments.