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Indicators too fast
Vindi_andy - 9/3/09 at 10:58 AM

Ok here goes I am an electronics eng by trade so I understand what should happen and I think I know the reason But i just wanted your input.

Fitted rear LED indicators bought from SVC. Fitted the resistors they supplied for use with them in them live feed to the lights. Fitted front indicator which is a bulb type big square one also bought from SVC.

They still flash too fast, I suspect the front bulb is a low wattage so not enough combined load. Was getting late last night and I was knackered from spending the whole day working on the car so didnt take the bulb out to check.

Any other thoughts.

matt_claydon - 9/3/09 at 11:04 AM

The resistors should be in PARALLEL with the lights, not series. Remember, you're trying to increase the current draw not decrease it.

(The idea of fitting the resistors across the lamp is to REDUCE the total resistance of the combination; putting them in series with the lamp increases the resistance and if anything will make them flash even faster!)

[Edited on 9/3/09 by matt_claydon]

Paul TigerB6 - 9/3/09 at 11:05 AM

Have you fitted side repeaters yet?? Sounds like the overall wattage is still too low so simply fitting the repeaters may solve the problem.

Agriv8 - 9/3/09 at 11:06 AM

Yes - buy a digital flasher relay from abay for less tha a tenner delivered thats what I did

These will flash the correct pulses regardless of load .

Regards

Agriv8

02GF74 - 9/3/09 at 11:10 AM

don't waste your money on drop resistors; push the boat out and buy an electronic relay, about a tenner - these do not rely on current drawn.

the drop resistors waste electricity so power that could be used for forward motion is being sapped, albeit a very tiny amount, to heat up the resistors.

Vindi_andy - 9/3/09 at 11:28 AM

unfortunately already bought the resistors so I have already "wasted" my money.

regarding connecting in paralell v series I did say it was late brain wasnt working properly will try that tonight.

God its been a long time since I used my electronic/electrical knowledge in anger.

MakeEverything - 9/3/09 at 11:34 AM

quote:
Originally posted by Vindi_andy

God its been a long time since I used my electronic/electrical knowledge in anger.


Erm..... so youre not a practicing electronics engineer then?

[Edited on 9/3/09 by MakeEverything]

Project7 - 9/3/09 at 12:19 PM

quote:

Erm..... so youre not a practicing electronics engineer then?


No, he just doesnt get angry usually

Vindi_andy - 9/3/09 at 12:42 PM

quote:
Originally posted by MakeEverything
quote:
Originally posted by Vindi_andy

God its been a long time since I used my electronic/electrical knowledge in anger.



Erm..... so youre not a practicing electronics engineer then?

[Edited on 9/3/09 by MakeEverything]


Not for at least 12 years apart from the odd bit here n there

[Edited on 9/3/09 by Vindi_andy]

splitrivet - 9/3/09 at 02:26 PM

If your resistors are wired correctly as per Matts post check your bulbs in the front are 21 watt not 10 or 15 as in quite a few foreign imported indicators.
Cheers,
Bob

Meeerrrk - 9/3/09 at 11:09 PM

how have you connected the resistors, because i quickly fitted some as a trial with those scotch lock connectors and they made such a poor connection, they werent working properly.

Vindi_andy - 10/3/09 at 09:50 AM

They were proper soldered joints with heatshrink over.

Having read the earlier post re resistor and dredging the memory banks for Ohms law it became clearthat I have connected the resistors incorrectly.

Should be paralell not series

Vindi_andy - 11/3/09 at 08:24 PM

OK quick update.

Thanks to the reminder about ohms law where P=VI and V=IR regarding the resistors being in parallel to create the additional current drain and connecting the side repeaters the indicators now flash at the correct speed

Yipee!!!