GT6 Mk3 ballast resistor query.

[Qu1ckn1ck]

My GT Mk3 has no visible ceramic ballast resistor connected to the coil positive terminal.  I have read that it may have a ballast resistor wire instead but my coil has only one feed wire connected to the positive terminal and one wire from the negative to the dizzy.  Is it possible that my car could have a hidden ballast resistor wire spliced into this single feed somewhere rather than two separate feed wires terminating at the positive terminal ?

 

I am trying to find out why a new Powerspark Distributor and Viper Coil refuse to perform when installed in place of the old Delco dizzy and coil. 

[Pete Lewis]

With a simple meter measure the coil primery should be 3 ohm for 12v and 1.5 if ballasted.

to measure the coil feed voltage you need the points closed as there is no external ceramic ballast

then check the coil positive if its a dropper the wire is normally a dull whote witha pink trace

 

its looking from your pic to not have these.

 

The missing yellow white feed from the solenoid also makes this un balasted

its would be unlikely to start if it was ballasted and this link is missing.

 

well something like that

 

Pete

[dougbgt6]

My GT6 has a ballast wire but my coil is the same yours, only one wire on each of the coil terminals. The wiring diagram shows the ballast wire, pink and white, as an additional wire on the + terminal of the coil, but this is incorrect. My pink and white goes to the other end of the coil + wire, originating on the starter solenoid. Yours may be the same?

 

http://triumphspitfire.com/images/wiring/GT6MkIIIwiring.jpg

[Gully]

Early cars such as yours Nick would have had the ballast resistor originally, with later ones having the resistor wire. So, if you still have the original wiring harness you should be missing the resistor wire, but after 40 years who knows what has been done! As Pete has outlined, best way to check is by looking at what you had working before and establishing the coil resistance.

 

Gully

[Pete Lewis]

Yes it dosnt matter which end of the yellow white the balast joins in

 

the result is the same

[Qu1ckn1ck]

Thanks everyone for the suggestions.  I have traced the white/yellow wire from the ignition coil + terminal to a terminal on the starter solenoid.  The only pink/white wire I can find is this one - joined to a white/no trace and both coming out the loom near the battery and fuse box.

 

 

Having bought a shiny new DMM I appear to have come up with some rather odd readings:

 

Old (working) coil resistance = 1.9 ohms.   The new Viper coil = 1 ohm.

 

I was expecting the white/yellow wire to show a dropped voltage, but on checking at both the coil and the starter solenoid disconnected ends, with the ignition on, it showed the full battery charge of 12.47 volts.  I can only assume that there is no ballast resistor wire active in the ignition circuit.

 

Unless anyone can suggest any other possibility, I guess that my Powerspark distributor or Viper coil must be faulty ?   Looks like another phone call to Simon Lucas on Monday. 

[dougbgt6]

Or the multimeter's faulty!  But seriously I have had a dud one of those.

 

I should also add that the pink and white wire is a dull white with a feint pink fleck. The pink has badly faded over the years and is not easy to spot. 

[Pete Lewis]

you need the ground the points wire to get the dropped voltage so  the  coil  primery is 'loaded' 

or you get battery volts showing 

the ballast murky white and dull pink  normally  start from a 2"   white  pigtail off the ignition switch and then dive off into the loom.

 

pete

[Qu1ckn1ck]

Checked the ignition coil again with CB terminal earthed and the DMM reads 6 volts at the positive terminal so my GT6 system definitely has a ballast resistor wire hidden in the loom.  None of the GT6 wiring diagrams available in my manuals or online match my loom so no help there.  Eventually found the start of the pink/white resistance wire pigtailed with a white wire into the loom near the battery and the other end pigtailed with the white/yellow bypass wire into the loom near the alternator.  I now intend to link the white feed wire behind the battery to the white/yellow bypass wire now removed from the starter solenoid to provide a short, unobtrusive and easily reversible 12 volt feed to the electronic distributor and coil.  Just hope that works.

 

Many thanks all for your help an advice.

 

Nick

[Pete Lewis]

thats good,  Im a fond believer in bin the whole ballast idea and stick to what god gave it and remove any myths about what the hecks fitted ,

in general a 12v sysytem uses a 3 ohm coil,  anything less increases the current used and is likely to burn points melt electronics and more,

 add in some coils are 6v  1.5 ohms but marked up as the base ignition of 12v  sometimes labeled as 12v ballasted  or  ...not 

 

its was an idea to boost ign when the poor old battery and cranking in poor conditions  drops the coil voltage

the ballast idea giving a 6v coil a 12v feed was to compensate the drop,and aid cold starting !!!  

 

ive never had a car not start in over 50years of motoring ,  

 

now i need a boost    ha !

[Qu1ckn1ck]

My 6v coil measures 1.9 ohms resistance across the primary terminals.  Car starts perfectly whether I have the 12v by-pass link connected to the starter solenoid or not.  I thought that the High Energy Electronic Distributor and Coil would be a direct replacement for the old c/b  points system which is working quite happily.  If I had known the hassle it was going to be, with no instructions supplied, a hidden ballast resistor wire and no relevant diagrams for the loom in my car, I wouldn't have wasted my time and money on the electronic replacement.

[Pete Lewis]

many have been in the got the tee shirt mode for the what have i got nothing

makes sense ignition  circuitry  headache 

  Im sure now its all sorted it will be fine and no more points gaps to have to set any more.

 

Pete

[Qu1ckn1ck]

Continuing hassle with the High Energy Electronic Distributor, Viper coil and  HT leads.  Despite adapting the GT6 loom to provide a 12v feed to the High Energy Coil  there was still no HT spark at the plugs.  The supplier then sent a replacement electronic module (FOC) to be fitted to the new distributor - still no spark and so the electronic system is removed from the car for the third time.  Further phone conversations with the supplier today, who finally suggested testing the resistance of the coil secondary circuit.  The result - now awaiting a replacement coil !

 

This was supposed to be an easy half hour job directly replacing the old coil and distributor with shiny new electronic ones.  Ten days later the saga continues.