'01 Jetta front turn signal current?

Terrific-In-Tahoma

Veteran Member
Joined
Jun 4, 2012
Location
East-of-Toronto, Ontario, Canada
TDI
'01 ALH Jetta M5 / 05 BEW Jetta Wagon A4
Had a strange problem with a '01 Jetta ALH front turn signal.

Initially the signal indicator went on double speed, saying that something was wrong with the turn signal lights , either front or back.

Pulled over , after looking for a safe place, and sure enough, when the turn signal stalk was set to the right, the rear lamp would light up, and the fender marker would go off, in sync with the fast speed of the 'blinker' relay.

When I checked the front turn signal, there was no blinking light, just the constant light from the Daytime-Running-lights (Maybee?) as I had all lights on with the headlamp switch. (I normally drive with them turned on , when travelling after dusk, or on the 'big highway'....

Went to have a look at the lamp, and see what type it was, but then the next day the problem stopped, and the lamp functioned as normal with a regular blink-blink cadence.

The third day, the fault happened again (today saturday), so I was able to confirm if the power was going to the bulb or not, and perhaps replace the bulb.

To my amazement, the connector for the bulb filament, had become hot enough to melt the plastic of both the bulb holder, and a bit of the bulb socket.

the actual contact has a hole burned through the metal at exactly the location where the wire inserts for the turn signal 'source'.

So, it got me to wondering.

Does anyone know how much current is being drawn by the 12 volt bulb when the turn signal is being activated?

IS there a METAL housing instead of the plastic and plastic bulb, that could be substituted for a 1157 type bulb instead?

Seems a bit cheezy, but then this is VW, for building a plastic housing when a metal one actually absorbs , and withstands more of the heat from the incandescent bulbs.

Anyone have a contact get so badly pitted from arcing, that it went completely through?

Thanks.
 

Terrific-In-Tahoma

Veteran Member
Joined
Jun 4, 2012
Location
East-of-Toronto, Ontario, Canada
TDI
'01 ALH Jetta M5 / 05 BEW Jetta Wagon A4
Had a strange problem with a '01 Jetta ALH front turn signal.

Does anyone know how much current is being drawn by the 12 volt bulb when the turn signal is being activated?
Found this bit of info on the side of a Sylvania Amber Bulb 2-pack, 3357/3457NA.

26.9W / 8.3 W

Was printed on the side of the package.

So, that answered the question (sort of), as to how much current goes through the tiny wire, when the circuit is being activated.

If the bulb's power is 26.9 Watts (P), and the nominal voltage of the bulb is 12.8 to 14 Volts(E), then (from Ohm's Law),

P = E / I

Re-arranging for current ( I) , then

I = P / E

So for my case, P = 26.9 , E = 12.8 , so I then is 2.10 Amps , pushed through a resistance of 6.09 ohms.

However, these are Incandescent Light bulbs, and during the first bit when the filiament is COLD, the INRUSH current is peaking at 21 AMPS!

[incaandescent filiaments have a starting resistace, that is approximately 10% of the running resistance, when it is hot]

No wonder the !@#$%^ connector burned out!

Given, that the bulbs themselves are the problem , I looked into LED's.

...that is for another thread.

I hope this helps someone else who is wondering why their light bulbs burn out so quick,

I am looking into a 'better' solution. (See part 2).
 
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