New starter motor, unused wire

[greensleaves 0]

I have recently upgraded my starter motor on my mk3 1971 2.0 GT to a powerlite starter. I have connected all wires but one. it is a yellow and black wire that has a round connector that used to be connected to a screw thread type fitting on the back of the original motor. There is no place for this wire on the powerlite apart from a second main copper terminal which when connected to that the engine won't start. As soon as I disconnect it the engine stars and when I reconnect it shuts off? I believe that this used to be the cold start wire to give extra beans. I want these extra beans as I feel it will struggle to start on those cold winter mornings....... Any suggestions?

I'd also like to add that the original starter started the car with a not too great battery but the new starter wore that battery out which is another reason I think the boost wire would help.

Thank you

[do it sideways 41]

You upgraded.,,your old starter worked with a naff battery, the new one won't, you have no wire connection for coil 12v feed, me thinks you're not upgraded , but down graded,,, ford's,lucus, bosch. Spent a lot of money developing a starter. Stick with ford's idea, ,,

[greensleaves 0]

Thanks but the new starter is supposed to turn the engine over twice as fast and draw less amps from the battery and its lighter in weight so it is an upgrade, I think the battery issue was, actually a battery issue and after getting a new battery it's been all good .... I would still like to attach the boost wire if possible though which was my main question.

[bortaf 85]

That wire as Steve says gives the COIL a full 12V when cranking (the coil normaly runs at 9V) come colder weather the car will have starting issues so you need to use a suitable starter, you dont have one at the moment, not all race style "upgrades" make it in real life and are retrograde in fact :(

TBH you dont need a starter to do that unless you have a high comp engine and a small race battery but with points you do need that 12V boost to the coil when cranking so i'm affraid it's either use a sutable starter/solenoid or fit 12V electronic ignigtion, remeove the ballest wire and upgrade the coil to 12V, .

Have you contacted the company that made the starter to see if they do a solenoid with the extra connection ?

[greensleaves 0]

Thanks bortaf. It seems that's the solution to the problem. I already have a new 12v coil. I got a multimeter reading from the coil wire that registered 12v so I did away with the ballast resister and old 9v coil years ago and changed to a 12v coil. I just assumed the cold start wire would give extra boost wether it was 12v or 9v. So I can just do away with the wire and tape it up!

I did ring the supplier and told them the problem but he couldt figure out why the wire wouldn't work just by attaching it to the extra terminal. When the wire IS touched to the extra terminal the fan comes on which tells me it's always live. I was under the impression it came live when the ignition is turned on and then disengages when running?

[stevewes 15]

You could achieve the same effect by using a relay activated by the wire to the solenoid. This would close the relay contacts when cranking and you would then be able to send the 12v to the coil.

[greensleaves 0]

Stevewes, would I gain anything by using this method seeing as I'm already using a 12v coil or does the cool lose voltage while cranking? I feel like I'm delving into deeper areas that I don't fully understand.

[do it sideways 41]

No, you can get a 12v feed to the coil, but a totally pointless exercise. Your high power starter is sapping all the amps which is the power behind the 12v, if you have electronic ignition then you don't need a separate feed if not go back to a 9v coil with resister wire and run your 12v feed.

[greensleaves 0]

I still use points not electronic ignition. why should I change to a 9v coil and resister wire when my wire from the positive terminal reads 12v with ignition on? The new starter should be drawing less amps than the original starter too, it is a reduction gear motor turning over twice as fast, which is what I wanted and what I've got. It's just a matter of this bloomin cold start wire and what to do with it ... I guess I'll wait till winter and see what happens?

[Danish 294]

why should I change to a 9v coil and resister wire when my wire from the positive terminal reads 12v with ignition on?

 

While a conventional starter motor is cranking, the battery voltage drops to about 9v.

 

The original points system is designed for 9v. When the engine is running, the ballast wire drops the 12+v to approx 9v, while cranking the ballast is bypassed so the coil still gets about 9v.

[greensleaves 0]

So a 12v non ballasted coil is not a good system to have? The 9v coil ballasted is better?

[dgo 68]

So a 12v non ballasted coil is not a good system to have? The 9v coil ballasted is better?

Yes it's designed to give a full spark while the starter is pulling down the voltage.

[stevewes 15]

So a 12v non ballasted coil is not a good system to have? The 9v coil ballasted is better?

Yes, if you're sticking with a points system then keep your original ballast and 9v coil.

 

To overcome the lack of third wire connection on your new starter, connect relay as follows:

 

(i) Relay coil - connect between earth and starter switch feed to starter motor (to close relay contacts when engine is cranking)

(ii) Relay contacts - connect to each end of the ballast (i.e. short the ballast out when cranking) - in effect, one end of the ballast goes to ign+ and one end to coil+ so the relay is removing the voltage drop effect of the ballast during cranking, which is exactly what the extra wire on the original starter did.

 

Just one relay and four connections - what could possibly go wrong? :rofl:

[MK5 V8 1]

i'm assuming you have a nippon denso style starter as it's a powerlite, you'd have been better off getting one of these and no extra wiring or relays needed :thumbup:

[greensleaves 0]

Damn I do wish I'd bought that starter motor you mentioned it would have saved a lot of grief. It's all a bit too late now.

 

That's it then I'm putting a ballast resistor in and changing the coil. I kept hold of the original resistor for ages and ages but think i must have thrown it away after having a ruthless clear out 😢 I take it I could use this one that button power have? http://www.burtonpower.com/micro-dynamics-ballast-resistor-mdbr01.html