ballast Risistor question
Discussion
Hi all.Ive got a daimlar dublesix coupe 1977 which has a ballast risistor on the ignition curcuit next to the coil,is it normal for it to get hot ?,when i mean hot its like you can,t keep your finger on it for more than a phew secounds when its been running for about 5 min,s or more.....
It's there to drop the voltage supplied to the primary side of the ignition coil during normal running. It's swithed out of the circuit when starting to compensate for the voltage drop of such a heavy electricial load and enables the coil to still generate enough secondary voltage to fire the plugs on start up.
It'd figure it will heat up when the engine is running as it's continiously passing current - but I have no experience of early V12 ignition systems or how each evolution of them is configured so can't advise on what's normal.
Might be worth checking the points gap if your system has them and dwell angle and making sure the coil is the correct type for your car though. If you have a condensor in the system and it's failing that might potentially cause heating issues elsewhere due to the back EMF current from the coil floating about in the system the condensor is meant to absorb.
If the points have closed up current will be passing for longer than designed for during the ignition cycle - and of course the timimg will be out too unless it's been adjusted without checking the dwell angle first, and if an incorrect or non ballast resistor type coil has been fitted to a ballast resistor system (if it works at all) would change the current drawn through the circuit as well.
It'd figure it will heat up when the engine is running as it's continiously passing current - but I have no experience of early V12 ignition systems or how each evolution of them is configured so can't advise on what's normal.
Might be worth checking the points gap if your system has them and dwell angle and making sure the coil is the correct type for your car though. If you have a condensor in the system and it's failing that might potentially cause heating issues elsewhere due to the back EMF current from the coil floating about in the system the condensor is meant to absorb.
If the points have closed up current will be passing for longer than designed for during the ignition cycle - and of course the timimg will be out too unless it's been adjusted without checking the dwell angle first, and if an incorrect or non ballast resistor type coil has been fitted to a ballast resistor system (if it works at all) would change the current drawn through the circuit as well.
rabowman said:
I have the same on a RV8 4.0 fitted to my 'Cobra' have also had it on loads of MGs and Triumphs....never found it to be more than warm
Thats intersting only warm ,mine gets very hot,i was hopping that some one on here may have the same car as me to compair or even a early xjs pre HE which is nearly the same.tortop45 said:
rabowman said:
I have the same on a RV8 4.0 fitted to my 'Cobra' have also had it on loads of MGs and Triumphs....never found it to be more than warm
Thats intersting only warm ,mine gets very hot,i was hopping that some one on here may have the same car as me to compair or even a early xjs pre HE which is nearly the same.My '86 Merc 500 has a shield over the resistor to prevent injury it gets so hot.
J
jith said:
tortop45 said:
rabowman said:
I have the same on a RV8 4.0 fitted to my 'Cobra' have also had it on loads of MGs and Triumphs....never found it to be more than warm
Thats intersting only warm ,mine gets very hot,i was hopping that some one on here may have the same car as me to compair or even a early xjs pre HE which is nearly the same.My '86 Merc 500 has a shield over the resistor to prevent injury it gets so hot.
J
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