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Ballast Resistor.... Do I Need It?

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have read that it drops normal ignition voltage to around 6v for when engine is running

and when you need to start car it will double it and bit to get the 13.8v to crank engine.

 

what i wanna know is, is it safe to run with out one?

 

I swapped over a electirc dizzy, and coil into my golf.

now i find the dizzy dead so back to points.

 

but i kept the higher power coil, i got car running without a ballast resistor and its fine. but ive read it will burn out points quicker and wear out the ignition quicker cause its at max volts the time car running. True?

 

Also, how does it hook up to coil?

 

Cheers

Dan

 

(off to google it more :S )

your car will run fine for a while if you have a resistor type coil-running no resistor, but will soon burn out on a longer trip.

 

If you have a non resistor type coil, it will run fine, no worries.

 

As for wearing points quicker, probably. A good upgrade for increased spark though.

  • Author

how do i tell what type coil it is?

 

From what i can tell its a High Powered one that didnt use a resistor when using electric dizzy..

  • Author

Ahhh don't worry, found what i needed :)

 

Will go double check it tomorrow. if its not a 12v internal resistor coil, ill go buy one :S

Hrmm... I bypassed my ballast resistor when it broke (was horrible trying to find what was wrong with my car at the time).

I don't really remember WHEN it happened, but I think it may have been BEFORE I've gone through 4 starter motors

(in 8 months) Would/could this be the cause? The solenoid is the bit that ALWAYS breaks/doesn't function. When they're

on their way out they would start to click on and off.

It shouldn't affect the starter motor.

 

As Falken said, the cars run low-voltage coils designed to work at 6 or 8volts, and when you hit the 'start' part of the ignition it bypasses the resistor and feeds the battery voltage directly to the coil. With the starter working the battery can only give 8volts, so the coil works perfectly to start the car. The coil should never run at 12volts.

 

Release the key and the ballast resistor cuts back in to drop the normal 12v back to 8 for the coil. Everything else in the car is designed to run on 12V.

 

The option was to have a 12V coil running at only 8volts trying to start the car. That's what the high-powered coil Falken has is designed to do.

 

If you bypass the resisitor then your 8volt coil is getting 12volts pumped through it all the time.

  • Author

could be that.

 

your system is running 12v constant now without a resistor.

a internal resistor will fix that problem, pretty sure thats what i got in golf, hoping it is anyway.

 

Might have a resistor laying around though. how does it wire in? one end on coil and other earths to body?

 

Edit

 

SO Altezza,

 

If i have a Internal Resisted Coil, that means i don't need a external ballist resister because the coil automatically runs at 6-8v and will flick to 12v to start car?

Edited by Falken_KE30

If its a coil that needs a resistor then run one, otherwise when the car is driven for a while it'll jump around and carry on and generally not drive (as i found out)

If i have a Internal Resisted Coil, that means i don't need a external ballist resister because the coil automatically runs at 6-8v and will flick to 12v to start car?

 

That is true- here's a bit about it.

 

http://www.secondchancegarage.com/public/122.cfm

 

The next component is the ignition resistor. It is necessary because ignition coils are designed to step up battery voltage high enough - and fast enough - to keep the engine running at high rpm. That means that, as designed, the coil would produce too much high voltage at low rpm and heat up. Automakers long ago realized that there were two solutions to the problem: using two coils (one for low rpm and one for high) or an ignition resistor. Obviously, the resistor approach is the least expensive and most reliable, so that's what they did. The resistor used varies is resistance as a function of temperature, and limits the voltage to the coil accordingly. As the engine revs up the resistance lowers, allowing more voltage to the coil for fast running, and the reverse happens when the engine slows down. At idle, for instance, only about 7 volts is going through the coil primary windings.

 

The only time the resistor is out of the circuit is during startup, when the engine needs all the spark it can get. It's bypassed in the ignition switch's start position so that, during starting, the coil gets full battery voltage. Ignition resistors can take many forms, depending upon the manufacturer of the vehicle. Some builders mounted a big resistor on the firewall and some others utilized a special type of wire (resistance wire) running from the ignition switch to the coil. Still others used coils that were built with an internal resistor. None of these is any better an approach than the others, but it's important to know which type you have, and that you have one!

  • Author

Cheers mate, that clears it up heaps :S

 

will go check mine after me coffee and make sure its a internal one

  • Author

ok, found that the coil is a Bosch #00041

 

can't really find anything on it, seems to be a OEM coil for VW's, audi's ect. usually with part numbers 221 122 203 or 211 905 115B to name a few

 

Dunno if i need to run a ballast resistor on it

I would- See if you suffer misfire from too low an input voltage, rather than run it on too high a voltage & boil the coil.

 

Looks like it fits an '80 VW Kombi, amoungst others! :lolcry:

 

http://www.bus-boys.com/tuneup.html

 

This it?

 

http://www.streetperformance.com/part/bosc...1997-00041.html

  • Author

thats the one but mines black, but still has that green sticker

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