coil ballast resistor

Technical questions and answers
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redtailhawk
Posts: 68
Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

coil ballast resistor

Post by redtailhawk »

Hi
can someone please tell me where coil ballast resistor is situated have traced white/purple from starter to going through bulkhead behind dash and white wire from fuse number 7 but now struggling . wire which connected to coil positive and then coil ballast resistor resistor was not connected at ballast end
thanks Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
sebking
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resistor

Post by sebking »

On mine it is to the right of the Coil - white tube about 2.5 inches long.
Seb
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redtailhawk
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Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

Post by redtailhawk »

Just checked mine none near coil .
SEb what wires have you got connect to coil .I have black wire with male spade on end which connects to negative side of coil suspect positive side I should have white/purple wire from coil ballast resistor ?don't member seeing coil ballast resistor when I changed the bulkhead .
Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
map1275
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Post by map1275 »

As per your handbook and workshop manual, it is forward of the coil, sharing one of the two coil mounting bolts.
map1275
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Post by map1275 »

Before you go any further, you need to confirm whether the coil you presently have is intended for a resistor. You may have to pull it off and read the underside of the base to do this!

The period Lucas coil is difficult to locate and can be expensive. The current Lucas replacement coils are relatively cheap, However NOTE that a new resistor is an additional, extra part to the new coil.
redtailhawk
Posts: 68
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Location: Preston England

Post by redtailhawk »

Have bought new coil which is correct part number as on old coil the female connector snapped off but can't find any wiring for positive side of coil including coil including ballast resistor looked in hand book one picture but doesn't show ballast resistor also looked in worshop manual couldnt find anything .
Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
map1275
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Location: Brisbane, Australia

Post by map1275 »

Well it's in my handbook on page 83 between the screen wash tank and coil. Plus being listed in the wiring diagram on page 138.
redtailhawk
Posts: 68
Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

Post by redtailhawk »

Saw picture on p85 a time I didn't know until Seb,s post .have been using wiring diagram to trace wires .traced them to going into dash but can't find out going wire yet which should be white/purple ?have just ordered a coil ballast resistor .
Will have another look today
thanks Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
redtailhawk
Posts: 68
Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

Post by redtailhawk »

Now sorted wiring just need to wait for new coil ballast resistor to come.
Thanks to everyone who replied
Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
redtailhawk
Posts: 68
Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

Post by redtailhawk »

Hi
got coil ballast resistor today. though ignition live went to one side of ballast and a wire from other side of ballast to coil positive . Then starter wire direct to coil positive side of coil . Now the but? Coil ballast resistor as spade connect on one side and a black wire with ring terminal on other side?the coil ballast resistor is a bearmach one correct part
number I can easily change black wire with to a spade connect on
thanks Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
disco2hse
Posts: 1637
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Location: Auckland NZ

Post by disco2hse »

It's been a while since I last used a ballast, but the ring normally attaches to the shared +ve post on the coil and the other end connects to the ignition switch feed. Of course it doesn't really matter which way around you stick the ballast.

I know this is for the Mallory, but it is a nice clear diagram.

Image
Alan

1983 ex-army FFR 109 Stage 1
2005 Disco 2 HSE TD5
map1275
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Post by map1275 »

If you had purchased the correct part it would have a standard Lucar terminal at each end. The correct coil will have three Lucar terminals and one of which will be female.

From memory the correct unbutchered loom has everything there for you. So there will not be any additional loose wires from the resistor to the coil. It is all incorporated into the loom.

As per your wiring diagram, 12 volts direct to coil only occurs during cranking. Otherwise normal 12volt supply enters one end of the ballast and exits the other circa 6 - 9 volts and then enters the coil.

So you will have two supplies in to the coil positive and one exit to the distributor, all as per your wiring diagram.
Last edited by map1275 on Sun Mar 18, 2012 5:08 am, edited 2 times in total.
disco2hse
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Post by disco2hse »

This sounds like the ballast you were referring to...

Image

1.6Ohm, pretty standard.
Alan

1983 ex-army FFR 109 Stage 1
2005 Disco 2 HSE TD5
redtailhawk
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Joined: Wed Nov 05, 2008 9:13 am
Location: Preston England

Post by redtailhawk »

Yeah that's the one I've got it is a bearmach oem one also got correct coil as well will wire up tomorrow what threw me was there was no coil ballast on it and the wiring didn't match up to wiring drawing have now sorted wiring to standard.
Thanks Darren
1981 Stage 1 SW
If it's not broken don't try to fix it
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