Lumenition Optronic Ignition, 12V MS4 Coil - How to wire in Ballast Resistor.

[Chilistag]

Gents (and Ladies!?)

I am trying to find out further information or more clarification in which is the correct way to wire in a coil to my 1976 MK II Triumph Stag with original 3.0L V8 engine. The car has very recently had a complete overhaul/restoration and a new Lumenition Optronic ignition system replaced (supplied as kit from Rimmer Bros). The car had been running with no issues and has barely covered 1,100 miles. The car broke down during a days driving last month with no immediate indication anything was wrong, engine simply died when approach traffic lights.


After investigation and trouble shooting it was identified that the 1st 12V Lumenition coil had failed. I purchased a new Lumenition MS4 12V coil, again from Rimmer Bros last week, and the car is back up and running. The Ballast resistor installed with new coil can be seen with one black wire attached on bottom side, top side of BR is marked +.
My concern however is the very short life span of original coil that did not have an apparent Ballast Resistor. This new MS4 coil clearly states (Must be used with Ballast Resistor, supplied). The instructions given with new coil are really not clear to me at all and I remain concerned the new coil may also fail prematurely.

I tried searching Lumenition site for further information but they do not list the FK.113 that was installed on my car. There is many conflicting theories on what is best to do!?!? Apparently the MK I Stag used a 6V coil with BR, the MKII Stag has a Ballast Resistor incorporated into wiring loom (Nichrome or Constantan?) It is a new wiring loom installed on my car.


As you can see from the pictures attached there is two joined wires (White/Yellow + White/Pink) on a single connector attached to + side of Coil, there is also the Red wire from the Lumention Module attached to + side of coil. On the - side of coil is the White/Grey wire and Violet wire from Lumenition module.
If i do have to wire in the Ballast Resistor can you please describe how to or supply wiring schematic. Would I have to install additional jumper wires or reconnect existing ones?


Any assistance would be much appreciated.

[DJT]

Hi,

The ballast resistor is that white ceramic thing attached to the coil mounting bolt.

Unless they have changed the wiring for Lumenition, the red wire should be the positive feed from the battery. A good source for that is the negative side of the fuel pump inertia cut-off switch, so that the ignition is cut at the same time as the pump in the event of an accident.

http://www.holden.co.uk/productimagesTD/030_250.jpg

If they have changed the Lumenition kit wiring, then I'm talking b******s

Dave

[elvimto]

Is it a Mk1 or Mk2, my 71 Mk1 has a ballast resister as it should I believe that the Mk2 does not have the same type, it has a resistor wire as part of the harness. If as you say you have a new wiring loom check with the people who made it to see if they installed the resistor wire and go from that point. I bought my car it had a Lumenition system fitted but I did change the coil to the Lumenition mega spark coil supplied by RB and I have had no problems. I do not have the car in font of me but from what you are saying the wire colors are not the same as mine which leads me to think you have a MK2, let us know what you find out, good luck.

cheers Stuart

[Chilistag]

Thanks Dave, much appreciated.

[Chilistag]

Thanks Stuart.

[Guest]

I am also learning about my Lumention at the moment. This is of no help to you , but my arrangement is (Mk 2) completely different to what you have. I only have one wire (black) on the + side of the coil and it comes from the ballast resistor. I also have 6 wires going in/out of the power module.

P1000850.jpg

So things must have moved on from whenever mine was fitted.

It looks to me that fitting Lumention must mean some other wiring changes - for example, with me having only one wire on the + coil side of the ballast resistor, it will be impossible to bypass that resistor during cranking, as others have said is the Stag system. Or am I missing something? Also, that part of the loom with the previous resistor in it must have been removed.

[V Mad]

I would always advise testing your ignition circuit to see if the coil and ballast is wired correctly. Many previous people will have worked on the car and some may have made modifications, so you cant take for granted that the wiring is correct simply by looking at the wires.

The test is very simple:
1. Connect a DC voltmeter +lead to the coil POS (+) and the -lead to chassis. Set to meter to a DC volt range of at least 15 volts.
2. Short the coil NEG to chassis (ie with a piece of wire and remove after test!). (it may be best to remove any other connections to the coil NEG as a precaution).
3. Switch on ignition, and read the voltmeter. This should read about 6 volts give or take a volt (it should be half the battery voltage).
4. Turn the key to the start position to crank the engine and note that the voltmeter reading goes up to about 12 volts (equals the battery voltage).

If the above test result is all OK then your coil and ballast is probably correct. If the result is anything else let me know and I will suggest what else to try.

[Guest]

Chris, rather that usurp Chilistags's topic any further, I'll Pm you about my wiring.

[V Mad]

Chris, rather that usurp Chilistags's topic any further, I'll Pm you about my wiring.

OK Don. But looking at your wiring, I agree, you cannot have the voltage boost on cranking since you have no other wire to the coil POS. Also I would be concerned that you may have a double ballast on your car, or has the loom ballast been bypassed?

[jbuckl]

Best not to assume anything with aftermarket wiring.


Also, that part of the loom with the previous resistor in it must have been removed

I am also learning about my Lumention at the moment. This is of no help to you , but my arrangement is (Mk 2) completely different to what you have. I only have one wire (black) on the + side of the coil and it comes from the ballast resistor. I also have 6 wires going in/out of the power module.

[ATTACH=CONFIG]15514[/ATTACH]

So things must have moved on from whenever mine was fitted.

It looks to me that fitting Lumention must mean some other wiring changes - for example, with me having only one wire on the + coil side of the ballast resistor, it will be impossible to bypass that resistor during cranking, as others have said is the Stag system. Or am I missing something? Also, that part of the loom with the previous resistor in it must have been removed.

[Guest]

Chris (and others),

I said I would PM you, but I think I’ll stay on here as it might help others now and in the future.

I looked up the history and the coil, leads, rotor arm and Lumenition power pack were all replaced in 2008, but the same garage that did the pre-sale service last year. I wonder why they did that. So there was a previous Lumention installation. It would have been done by a garage as the owners for the 20 + prior years were not DIYers.

Here’s what I measured. I used my el cheapo multimeter (I blew the good one up a while back), so the figures are not that accurate, but tell the story nevertheless.

As wired now

Coil –ve shorted to earth 3.8 volts ignition on
3.0 volts cranking


Ballast resistor shorted out

Coil –ve shorted to earth 5.5 volts ignition on
4.5 volts cranking


So it does look as if I am double ballasted, with no 12 volt coil supply on cranking as well. I’m surprised that the car starts at all! I have just put it in the barn and it fired up no problem. The instructions that came with the new Luminition coil tell you exactly what to do if you car has, or has not, got an existing resistor (1.5 ohms). They even mention the started solenoid wire. The book says this wire is white/yellow. I have only had a quick look from above so far and I didn’t see such a wire hanging about doing nothing. I will get underneath tomorrow for a detailed look. Need to get my garden done today.

I don’t know if this is the root cause of my hot starting/running issues, but it certainly won’t help and I will sort it out before I go tearing carbs to bits, perhaps needlessly.

Current thoughts on the solution are:

1. Short out the ceramic resistor

2. Connect up the starter solenoid wire to the coil +ve, if the wire can be found.

3. If no wire, then run a new one.

What do you think?

[V Mad]

Current thoughts on the solution are:

1. Short out the ceramic resistor

2. Connect up the starter solenoid wire to the coil +ve, if the wire can be found.

3. If no wire, then run a new one.

Yes Don, thats what you need to do. If that dont cure your problem then at least you can move on to another hypothesis.
Cheers

[Guest]

Today I have 6ish volts with coil -ve earthed and 10ish volts cranking. The wire from the solenoid was on the ignition side of the "not needed" second ballast resistor, plus the connection down below was bad. I'll keep an eye on that. Started it up with a woof, but the new pump was clicking lke mad - petrol spewing out of left hand carb overflow. It's one thing after another. I assume that is the float or float valve sticking open. I have ordered all the bits for a carb service. Am I right in assuming that the carbs come off together? Soon I'll know all about Strombergs, but I would have preferred to stay ignorant for a while longer. I will be out and about in the good old reliable (fingers crossed) MGB this weekend.

Thanks for help so far.

I viewed two other Mk2 cars with the ceramic resistor mouted where mine is and I now wonder if they too were double ballasted.

Chilstag - sorry for hijacking your thread. Did you get your Lumenition wiring sorted out?

[elvimto]

This is my first Stag which i have now had for four years but this is about the first year that I have been able to run it on a regular basis on the week end. I have a MK1 with Lumenition it seemed to run fine when I drove it from the garage went for a run and back to the garage without stopping. Lately it has been playing up on start up with much of the similarities reported. I have not got into the troubleshooting side but since I have done a bit of the electrical tracing checking wire connections etc I have eliminated some of the possible causes it does have me puzzled. On another forum one of the owners installed a manually operated soleniod dump valve with a line going back to the tank and this cured the hot start problem so that might be an answer. Really good advice on here and some good basic checks.

cheers Stuart

[Guest]

I don't think I will ever get into installing a dump valve, purely on the basis that other Stags manage fine as designed, as did mine before playing up recently.