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Matt, Mechanical Engineer
Category: Jaguar
Satisfied Customers: 23199
Experience:  BEng hons Mech engineering, in auto industry 22 years
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1966 engine number 7B58687-8 Should this have a 12 volt coil

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1966 engine number 7B58687-8
Should this have a 12 volt coil with a ballast resistor ? Or not ? It's eating points.
Customer: replied 10 months ago.
Should have said the engine is a Mk 2 jaguar


Jaguars of this era used 12v coils and if its got points burning out, then check the state of the condensor and the engine earth

they never used an external resistor and instead its important to check the resistance of the coil is correct

you need a coil with at least 3 ohms across the "-" and "+" terminals.

Customer: replied 9 months ago.
Thanks so far. I need to take another look at it and will get back to you.

no problem

just get back to me on this post

Matt and other Jaguar Specialists are ready to help you
Customer: replied 9 months ago.
Sorry for the delay. This engine is fitted in a vehicle built by Teal, makers of low volume sports cars and some kit cars. It is their type 59. The Jaguar 3.8 engine is plainly fitted with what looks to me like a ballast resister, flat oblong item pretty much in parallel with the coil, one wire going to the condenser on the distributor, which is a twin points Mallory. It breaks down regularly (sub 500 miles each time) 3 times in the past two years. Each time replacing condenser and replacing or cleaning points sets it running again. Coil has been renewed as well. Most annoying, because otherwise it's a very fun car.
I get no coherent answers from local garage. Any suggestions please ?


OK if its aftermarket then looks like you should run a Mallory coil to go with the Mallory distributor

and it looks like a Mallory coil will also run a ballast resistor too

Customer: replied 9 months ago.
Looking at the coil, the only words I can see without major surgery are. 'Intermotor'
Am I now back to wondering why condenser etc needs replacement all the time ?


Intermotor make pattern parts for the industry - the part quality is Ok but not at Bosch levels

I would suggest fitting a new coil from Mallory to go with the mallory distributor they also supply a ballast resistor to go with this coil too

Customer: replied 9 months ago.
Thank you for your help

no problem

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Customer: replied 9 months ago.
Something odd here, I rated it five stars but the system doesn't seem to recognise that.
Thanks again.