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motive
12-19-2005, 01:39 PM
The left turn signal of my Speedster flashes extremely fast, while the right side behaves normally. I put new 6 volt bulbs in both left side front and rear, with no change. Do I have a short somewhere in the left side circuit? I assume a bad ground would make it flash more slowly than normal. Any comments before I start snooping around with my multi-meter.

63Avanti
12-19-2005, 01:57 PM
Just bought an Avanti, so I have to dip back to my Valiant experience. "Fast" blinking on the old style 66 Valiant was either a partial sort, or a nearly blown lamp, or a load on the other side, and it was slow making you think that the other side was "fast."

Switch bulbs, and check fuses. Use dielectric grease on bulbs and fittings to eliminate the possibility of corrosion. Luckily, this car is too old for that phantom "dissimmilar metal".

motive
12-19-2005, 02:04 PM
The right side seems to blink normally, but the left is really, really, really fast! But thanks for the help.

Speedster

Roscomacaw
12-19-2005, 04:51 PM
Do the front and rear bulbs actualy blink at all???[?]

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
12-19-2005, 06:43 PM
Yes, they both blink but at about 5 times per second, compared with the right side which is noraml at about 1 time per second.

N8N
12-19-2005, 07:33 PM
Are you sure that you have the right bulb part numbers? A mismatch in bulbs can cause this; I've seen this happen on old cars that used 1034 bulbs when 1157s (which draw more current) were installed. Not sure if there is an analagous situation with 6V cars.

If that checks out, I would also look for a partial short on the driver's side. Are the wires OK in the little tubes going down to the front parking lamps? they were about dead on mine, and it's not hard to imagine the wires shorting to each other causing the turn signals to attempt to drive both the parking light and turn signal filaments at the same time. Same thing in the rear although there's somewhat less chance of those wires being crispy as they don't get as hot. You can check by turning on the parking lamps and seeing if one or both of the lights on the driver's side is unusually bright.

FINALLY... you know that the front bulb (1158) doesn't have indexed pins and can be installed either way, right? You need to check for proper operation before screwing the lens back on. This isn't the case in the rear though, it uses a regular 1154 (similar to 12V 1034/1157) bulb. This probably isn't your problem however as if the bulb were installed backwards it would cause the lights to blink too slowly. (or do you have a bad flasher, and the bulb is backwards on the passenger side?)

good luck,

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

Commander51
12-20-2005, 02:52 AM
The circuit cycles too fast because it has too much load on it. (You see this most commonly when adding trailer lights to a standard turn signal circuit.) That can be caused by a short, or by having the front bulbs installed with the brighter filiment driven by the turn signal circuit. As N8N suggests, reverse the position of the bulb in the socket and see if that helps. If not, you've got a gremlin and you need to inspect the wiring and/or improve the ground at the socket.

If reversing the bulb 'cures' the problem, but you want brighter turn signals after all, then get a heavy duty flasher canister from Little British Car Company www.lbcarco.com part #170-FV6.

BobPalma
12-20-2005, 06:59 AM
:) Within Nate's post is the seed of a related possibility: ;) One filament having broken off (burned through) inside one bulb and one part of the broken filament having fallen onto the turn signal filament. (I've seen this more than once, seriously.) It causes the turn signal filament to try to illuminate both filaments, drawing considerably more amperage than just the turn signal filament alone.

Easy detection here is whether or not the side in question was operating well and this started all of a sudden, without your having changed anything. [:0] If that's the case and these other checks fail, look for one bulb being much brighter than the other when rapidly flashing, indicating that two filaments, rather than one, are being "driven." [xx(] BP

BP

hank63
12-20-2005, 07:28 AM
Commander51 - pls help me out with this one. I've owned heaps of different cars. They've all behaved the opposite. With a bulb gone (less load) the blink rate has become superfast. With a trailer hooked up (more load) the blink rate has always slowed down.
You are saying the opposite?
/H

gordr
12-20-2005, 07:43 AM
Hank, I agree with you that usually a burned-out signal lamp is manifested by a faster flash rate.

But maybe, depending on the type of flasher unit, a heavy overload could cause fast flash rate, too.

Motive, I'd suggest you remove the lenses from ALL you turn signal lamps, and watch each one closely as it is working. Determine if one or both filaments are being illuminated. Compare right to left at both front and rear. Assuming the right is working correctly, the differences in the left side should reveal themselves.

A bad ground could cause your problem, and would cause both filaments in the affected bulb to light dimly. It MIGHT even cause the park/tail lamps on the other side to flash weakly, as the bright filament in the affected lamp will seek ground via the dim filament, which is connected to: the OTHER dim filaments. A bulb with an internal short, as Bob describes, might also have that effect.

I'd be more inclined to expect a bad ground than a short. Shorts, when they do occur, usually let the magic smoke get out, and things stop working altogether. Bad grounds are commonplace.

Any chance someone put a single-contact bulb in the front? That might do it. The non-indexed pins make it possible.

Gord Richmond, within Weasel range of the Alberta Badlands

Roscomacaw
12-20-2005, 03:11 PM
On the output side of a flasher, a short is alot less likely to "let the smoke out" of some wires. This since the flasher essentially IS a circuit breaker.[:I]
To eliminate the "bad ground" scenario, take a good jumper wire - clip it to the body of the light fixture (on a 55, that whole, chromed side grille at the front is the "fixture")- first with the front and then with the taillight body - to a good CLEAN ground and try the turn signals with each jumper wire placement to see if the situation gets better.
Since the side grilles are bolted to the center grille (and the one side TS works OK), I'd be inclined to suspect the rear fixture for a possible bad ground.
Of course, Bob's theory as to shorted filaments bears merit. I've never personally seen this but technically, it seems plausible.[}:)]

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

Commander51
12-20-2005, 04:08 PM
quote:Originally posted by hank63

Commander51 - pls help me out with this one. I've owned heaps of different cars. They've all behaved the opposite. With a bulb gone (less load) the blink rate has become superfast. With a trailer hooked up (more load) the blink rate has always slowed down.
You are saying the opposite?
/H


Yes, I know it's counter-intuitive, but I've had both occur in the recent past. In both cases the vehicles had old-fashioned mechanical flasher cans installed-- the ones with bi-metallic strips which open and close the circuit.

The more load passing through the flasher, the faster the strip heats up, the faster it will cycle. In both instances, by installing 'heavy duty' mechanical flashers, the cycle was slowed to acceptable rates--without doing anything else to the vehicles.

N8N
12-20-2005, 06:19 PM
I've seen flashers that work both ways. The *stock* flasher for a Studebaker is a bimetallic thermal flasher; if a bulb goes it won't blink at all, and if there's too much load on it, it will blink too fast. However, some more modern cars use electronic flashers which seem to have some kind of internal good/bad criteria for sensing a bulb failure - if it sees the load as "good" it blinks normally, if it sees it as "bad" it blinks about 2x as fast. And of course, either type of flasher can go bad as well... had one blinking fast on an old VW and just replaced it with one from a parts car, suddenly it didn't blink fast anymore.

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel