Replacement solenoid wiring

[BRS]

Hi, I would like some advice please; I think I posted this on the wrong section 2 days ago having struggled with the website I don't think it was reposted to this forum; at least I can correct the typos! I have had a replacement original type starter fitted but it has one less wiring terminal. The garage first connected the lead to somewhere then disconnected it. The motor spins fast but does not fire immediately as it did before; what should the spare feed be connected to, I believe it is the 12v boost to the coil. I have a lumenition ignition box which has not been any problem. Thank you

[steve.n]

Is there an external resistor fitted to the side of the coil, also are there two cables on the positive side of the coil. Steve

[StagJonno]

The original arrangement for both Mk1 (ceramic ballast resistor mounted on the coil) and Mk2 (ballst resistor included in the pink wire to the coil). There's a connection on the solenoid which puts battery volts direct to the coil during cranking via the White/ Yellow wire (colours can fade with age). This arrangement provides a better spark during starting, but the coil can only handle full battery voltage for a short time. Sounds as if your replacement starter doesn't have the internal switched connection and your coil can't generate enough volts on the HT side to get a fat enough spark (battery voltage is depressed when the starter is in circuit, plus I'm told that a rich mixture is harder to ignite than normal running mixture)..

The simplest way to correct is to fit the correct starter/ solenoid. Connecting the White/ Yellow wire to the White/ Red (which puts 12V to operate the solenoid) at the solenoid should work, though I guess there's a reason why this apparently simpler design wasn't adopted by the factory,

Jonno

[trunt]

Connecting the White/ Yellow wire to the White/ Red (which puts 12V to operate the solenoid) at the solenoid should work, though I guess there's a reason why this apparently simpler design wasn't adopted by the factory,

Jonno

Because the power supplied to the coil when the engine is running would feed back to the solenoid and operate it (or at least try to) It may also burn out your resistor wire or ballast resistor due to the extra load.

So don't do that!

But there may be a way to do that with a diode.

Terry

[StagJonno]

Because the power supplied to the coil when the engine is running would feed back to the solenoid and operate it (or at least try to) It may also burn out your resistor wire or ballast resistor due to the extra load.

So don't do that!

Terry

Duuh - of course. Well corrected, Terry. Must be the medication!. A relay with its operating coil wired in parallel with the solenoid control (White/ Red) could be used

Jonno

[trunt]

Duuh - of course. Well corrected, Terry. Must be the medication!. A relay with its operating coil wired in parallel with the solenoid control (White/ Red) could be used

Jonno

Of course relay, much simpler.. The electronics geek couldn't think of that easy solution!

[Lingen]

BRS. Who supplied your "Original type" starter motor? As it has come with the incorrect solenoid for Stag use, I think you should get them to replace it for you with the right one, at no expence to yourself.
Mike.

[BRS]

Thank you all, you have confirmed my worst fears that the feedback potential if connected to the other small spade terminal will damage something. I haven't had chance to check the coil resister or leads Steve n but I will reply on this. According to the diagram in the BL workshop manual the terminals are on different sides of the solenoid winding. The starter was supplied by Stag Mag advertiser J Paddock and I telephoned them before ordering, I was told there is only one starter for a Stag, it is a '72 Mk1! The original which kept clicking is numbered a 25684E "2M100", I have subsequently checked these on various websites and I don't know the difference to a "3M100". Unfortunately this is the third starter my garage has tried to fit. I was thinking of adding a push button switch to connect the 12v when starting.
Brian

[steve.n]

Brian. there should be two connections on the positive side of the coil. One provides 6 volts when the ignition is on, the other provides 12 volts when the engine is cranked. Checking these with a multi meter should tell you if you are getting full starter voltage, (disconnect the king lead first).
Steve

[Lingen]

Brian.
There is only one starter MOTOR for a Stag, but it should be fitted with the appropriate solenoid for a car with a ballast resistor circuit. And there is no difference between a Mk 1 Stag, and a Mk 2, manual or automatic. They are available all over the place, so I think you should ask the supplier to replace the one they have sent you, with one that has the correct solenoid. If they can't, then ask them to take it back, refund all your money, and you can get one from somewhere else! Sorry to sound bossy, but the one you have been supplied with is not for fitting to a Stag!
Mike.