Coil mystery!

[rodgers]

This relates to a Mk1 Ford Fiesta 1979. It's an 1100cc engine with a Ford distributor. The other weekend it spluttered to a halt on the M1 and the RAC guy, who had owned several old Fords, diagnosed a faulty coil and also recommended a change of condenser.

I've just replaced the condenser and I had a new coil ready to fit as well. According to everyone in the world I need a ballasted coil. I fitted it and had no joy whatsoever. It will run when turning on the starter motor but otherwise it dies almost straightaway.

The coil I took off is marked as 12v 203 Standard. The replacement I fitted is marked 12v 202 Ballasted.

Try as I might I cant find a 203 Standard coil anywhere. Do they even exist??

This seems very odd to me - I bought the old coil from a mainstream motor factor about 5 years ago and it ran fine. Not sure why that type would no longer be around and why the new one doesn't work.

When garaged the car was quite wet and the cap has been off the distributor for a few weeks while its been in there. Could this all be down to moisture getting into the distributor?? The engine bay is quite damp.

Any ideas here??

[mr rusty]

Ignore the numbers on the coil, they'll just be manufacturers codes. If you took off a standard 12v coil then replace it with one, presumeably someone's done away with the ballasting at some point, not uncommon in the cars heyday.

Any normal 12v coil will do, just take the old one to a decent factors, show them, and get one with the same connectors, i.e. spades or poles or change your connectors to match.

[stagman]

just a thought - "if" it has a ballasted system and will start with the starter but then dies it "could" be the ballast resistor or that feed to the coil. A ballasted system works by having a say 6volt coil fed through a resistor to drop the volts to 6volts but by passes the resistor to put 12volts though it for starting to get a big spark, keep putting 12v through though and it will burn out. 12v feed often comes as a second wire from the starter solenoid. You cannot rely on just looking for a ballst resistor by the coil as some cars (eg later Stags) have them built into the wiring loom.

[rodgers]

Ignore the numbers on the coil, they'll just be manufacturers codes. If you took off a standard 12v coil then replace it with one, presumeably someone's done away with the ballasting at some point, not uncommon in the cars heyday.

Any normal 12v coil will do, just take the old one to a decent factors, show them, and get one with the same connectors, i.e. spades or poles or change your connectors to match.

Best news I've heard all day. Thanks mate!

[Wicksy]

I concur with Stagman - what you describe is a classic failure symptom of a ballast coil running Ok during cranking but cutting out as soon as you release the key. Get your meter out and check the supply to the coil with ignition on, it will be 6 volts if a ballasted circuit, if it's zero then work back to the switch. I've also seen a 6volt (ballast coil) with a cracked nose piece which sparked enough to run the engine during cranking with 12 volts but was so weak at 6 yolts, due to arcing, that the engine died every time like yours.
If you see 12volts at the coil then sub another known Seviceable 12 volt coil.

[Luxobarge]

I concur with Stagman - what you describe is a classic failure symptom of a ballast coil running Ok during cranking but cutting out as soon as you release the key. Get your meter out and check the supply to the coil with ignition on, it will be 6 volts if a ballasted circuit, if it's zero then work back to the switch. I've also seen a 6volt (ballast coil) with a cracked nose piece which sparked enough to run the engine during cranking with 12 volts but was so weak at 6 yolts, due to arcing, that the engine died every time like yours.
If you see 12volts at the coil then sub another known Seviceable 12 volt coil.

^^^WHS^^^ +1.

I doubt your coil is faulty.

[Majicmark]

All above is good advice . Fords use a ballast wire built in to the wiring harness. It is usually near the bulkhead area and is a grey cable with a bullet connector on each end ( if memory serves). It is not uncommon for them to burn out through age and will give you exact fault you have as when engine is cranked the system gets 12v from ignition switch/starter & once key released reverts back to ballast circuit,which if this link is gone will leave no power supply. You can prove this by giving the coil a 12v supply to + terminal direct from the battery. You won't do any damage to the coil or points/condensor if only temporary supply(will burn points out if left for 1000 miles or so). You don't need to but it would be worth putting a 15amp fuse in supply from battery on test cable .