Voltmeter Settings/Ballast Resistor - Help Please

[Jaye R]

Hi

I'm just looking at the instructions to fit my new Flamethrower coil and they state that there are 2 types - one for cars fitted with a ballast resistor (1.5OHM - the one I have) & one for cars fitted without a ballast resistor (3 OHM).

Can anyone advise whether a 1990 S3 will have a ballast resistor fitted??

Alternatively I can test for it - according to the instructions my voltmeter should read 12v if no resisitor and less than 12v if one fitted.

Not knowing much about voltmeters please can someone tell me what setting to put it to and which line to read for the volt reading - there are 4 lines - 2 black & 2 green & numerous settings - I have attached a photo for reference...



Any help would be appreciated - don't want to go fitting the wrong type of coil and causing any damage.

Thanks in advance.

Cheers
Jaye

[mep12345]

Jaye R said:

Can anyone advise whether a 1990 S3 will have a ballast resistor fitted??

Don't know sorry

Jaye R said:

Alternatively I can test for it - according to the instructions my voltmeter should read 12v if no resisitor and less than 12v if one fitted.

The instructions don't give enough here the voltmeter should read this when testing between two points and the two points need to be identified so you test the correct point and read an accurate voltage.

Jaye R said:

Not knowing much about voltmeters please can someone tell me what setting to put it to and which line to read for the volt reading - there are 4 lines - 2 black & 2 green & numerous settings - I have attached a photo for reference...

Set dial to 25V DC and read off the black scale 0-250 (dividing reading by 10) to give you a reading i.e. 12V will be at 120 on the scale. However if you don't know where you are supposed to take this reading then you are on to a loser.

HTH

Mark

[Jaye R]

Mark

Fantastic - many thanks

The instructions do say where to connect the voltmeter - I just wasn't sure of the settings.

At least now I can test for the resistor - just got to wait for the kids to go to bed and I can get back in the garage to play.

Cheers
Jaye

[Le TVR]

All the V6 cars are fitted with ballast resistors, normally 1,3 ohms.

Actually finding it is another matter!

[tozerman]

Le TVR said:

All the V6 cars are fitted with ballast resistors, normally 1,3 ohms.

Actually finding it is another matter!

Here Here,I fullyu agree that all S cars have a ballast resisior which is basically a piece of wire built into the loom which lowers the resistance and voltage so that when starting the ignition gets 12V and when running it only gets 6V !! what the purpose of it is I don't know.
cheers.....Tony..

[Jaye R]

Thanks for the confirmation that there is a resistor fitted It puts my mind to rest that I'm OK to fit the coil.

Cheers
Jaye