ballest voltage
- Thread starter gosnell
- Start date
darth sidious
New Member
gosnell said:
The ballast wire on our old 2000Auto did go, as well as a friends 2200TC. The wire had worn/burnt through the insulation over time and was causing a dead short. My Dad said he saw smoke emanating from the wire!
Anyhow, the wire has the same or thereabouts resistance as the coil LT itself, so in theory anyhow, it should be half or thereabouts the battery voltage (assuming you measure on the + terminal of the coil). If you check, make sure the points are closed, otherwise you will read battery voltage.
If the engine is running, then the voltage will rapidly fluctuate from ~7-14 volts (points opening and closing, and assuming alternator pushes out ~14 volts), maybe register as ~9-10 volts on a voltmeter.
I never got around to checking this on our 2000Auto, I so wish I had though!
:xNote: It's possible that it will show the correct voltage even if there is an intermittent <now-and-again> short or cut in the ballast wire unless the potential fault decides to happen at the time of testing. Intermittent faults... ARGGHHHH!!!!!
as i found out with my 3500 the reson my ballast wire started to smoke and burn was because
the (coil boost) wire as i am going to call it ,was ahorting out somewhere or faulty at the ignition
switch so i hooked it up throught the starter relay with a diode(from an old computer power supply)
and it worked but i usaly have 9.2v after the ballast wire
the (coil boost) wire as i am going to call it ,was ahorting out somewhere or faulty at the ignition
switch so i hooked it up throught the starter relay with a diode(from an old computer power supply)
and it worked but i usaly have 9.2v after the ballast wire
Im thinking ditching the existing ballast supply, and then locating a good 12v supply and going to the coil and then fitting a stand alone ballast Re connecting the 12v supply direct onto the coil from the starter motor so as to give a 12 v supply only on start up and then throught the new stand alone ballast reducing voltage to the normal running of 7V hopefully this at least could confirm if I have a problem with the existing ballast wire as it wont be connected while testing.
darth sidious
New Member
glassjb said:
But is that 9.2V with the engine running or not, and is it powering just the coil? I'm not disputing, just trying to acquire some hand-on knowledge (which sometimes/frequently seems to disagree with theorised/expected results!)
At risk of sounding like I've got a bee in my bonnet... change the cappicitor in the distributor before you start getting too alarmed by this. There are some very poor quality capacitors out there which are capable of giving exactly these symptoms. They seem to either fail completely after about a mile's running or give this intermittant effect. If you can find an old Lucas one at the bottom of a tolbox, that's the safest bet at the moment! If it does turn out to be this, then I reckon you have an open and shut ( ) case fro an electronic ignition!
Chris
) case fro an electronic ignition!Chris
4 condensers have been changed in the last year none have appeared to have failed but I have changed them anyway, vacume advance unit, fuel pump, plugs ,leads, points, dizzy cap,low tension lead, coil replaced its the fact the starts well runs good untill it gets hot is the issue a lamp was attached to the plug leads and it can bee seen that there appears to be a breakdown, there is a nice even flash on all the plugs and it suddenly stars to get erratic. as i said at the begining could the ballast or a connection in the loom be breaking down this was why I was thinking of fitting a stand alone ballast
Just to reiterate what has already been said, I have a 2000SC and I get 7v to the coil which I believe is the correct voltage.
I believe you said you've changed the coil? just to close the case on the coil have you taken primary and secondary resistance readings from both and compared them? Reason I mention it is that coils can give the same symptoms as you mention as the resistance can rise in the coil as the temperature rises within it and will go intermittent. If it's a s/h replacement it could be giving the same faults, it's worth bearing in mind. Good luck and I hope you have a eureka moment soon.
I believe you said you've changed the coil? just to close the case on the coil have you taken primary and secondary resistance readings from both and compared them? Reason I mention it is that coils can give the same symptoms as you mention as the resistance can rise in the coil as the temperature rises within it and will go intermittent. If it's a s/h replacement it could be giving the same faults, it's worth bearing in mind. Good luck and I hope you have a eureka moment soon.
as a final note from me before the coil was changed to a new lucas dlb 102 the car was undrivable when it was hot I would need a tow truck to get me home,After the coil was fitted the car could now be driven with confidence except after about 14 miles of driving it will not tick over evenly when hot. the Plugs are a nice light brown in coloure because of the uneven running the car cuts out when put into drive
darth sidious
New Member
restojon said:
Thanks, that's the sort of voltage I would expect.
