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Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 2:52 pm
by Craven
Nothing wrong with the Powerlite diagram! As Eric pointed out you are overlooking the internal contactor inside the starter itself. The main external starter terminal does not go directly to the main starter winding but to one of an internal contact set, the other side goes the main winding, this contact set is not made until the solenoid has engaged the pinion in the ring gear.

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 3:03 pm
by ericbushby
2cams70
I have read the instructions and I still see no problem.
My starter was supplied with the trigger wire connected to the main supply stud.
As I said the motor can not run until the trigger wire is energised which then operates the solenoid and moves the pinion into mesh with the ring. Only then does the solenoid close the internal contact to run the motor.
If the pinion fails to enter the teeth, then you only hear the click, as reported by Dan and the motor does not get powered up even though there is power on the stud.
It is a sequence and the motor cannot run until the pinion is engaged.
Thank you for your efforts, but I do think we are diverting too much attention from Dan`s problem.
if you wish to disagree then perhaps we should leave it at that and concentrate on Dan.
Eric
Edit Cravens post above arrived while I was typing

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 4:04 pm
by collins_dan
Check my thinking on this. Get a standard 40 amp relay and mount to firewall close to starter. Run ground wire from position 85 to frame. Move current white/red from starter to position 86. Add new white/red from position 30 to starter. Run a new brown wire from other connection on starter (formerly from solonoid) to position 87. What gauge wiring should I be using? Thanks, Dan

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 4:56 pm
by ericbushby
Dan
Sorry I cannot confirm terminal numbers, but there is usually a diagram on the side of the relay.
The solenoid current on mine is 6 amps and I would expect others to be not much different.
Ordinary car wire of about 1 sq. mm. should be fine. This is rated at 10 amps continuous.
It might be a good idea to fit it where the original starter solenoid was. Sort of intuitive.
Eric in Burnley

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 7:17 pm
by gjz30075
Dan, any reason why you're *not* going back to the OEM Lucas starter? Seems like a good solution,
at this point.

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 7:49 pm
by Craven
collins_dan wrote:Check my thinking on this. Get a standard 40 amp relay and mount to firewall close to starter. Run ground wire from position 85 to frame. Move current white/red from starter to position 86. Add new white/red from position 30 to starter. Run a new brown wire from other connection on starter (formerly from solonoid) to position 87. What gauge wiring should I be using? Thanks, Dan

Dan,
That is the correct wiring for relay.
relay-with-diode.png
relay-with-diode.png (3.77 KiB) Viewed 441 times

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 8:46 pm
by collins_dan
Greg, I now have two perfectly good pre-engaged starters, a new battery and it would appear, two perfectly good ignition switches, so buying a relay seems like the easiest (and cheapest) solution. :D Before I do that, I am still planning to try disconnecting one at a time all of the other wires connected to the ignition switch, just to be sure that one of them is not causing the lost voltage. I am also going to try operating the switch with a screwdriver instead of a key. Basically, I want to duplicate the situation of connecting the multi-meter to the ignition switch when connected directly to the battery, which shows no drop in voltage when activated. All the best, Dan

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 9:03 pm
by mbell
Have you tried cleaning/redoing the engine to chassis earth connection?

Re: S4 Starting problems

PostPosted: Wed Sep 13, 2017 10:04 pm
by collins_dan
Not yet, we are about to move, so I may not get to do any of this within the next two weeks. I tend to think it is ok, because I get the same reading (11.3) whether I check at the switch with the ground by the door as I do when I check at the starter using the engine to chassis ground, and I get a 12.5 reading on the input. My biggest concern with the engine to chassis ground is the same as my concern with the line from the battery to the starter. I think they have corrosion within the lines, not at the contact points. They both have that bluish tint to the copper, so should probably be replaced. I will have lots of opportunity in my new garage, which has a much higher ceiling, so.... it may just be lift time! :D All the best, Dan

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 4:21 am
by 2cams70
OK guys, call me slow, but I can finally see how that Powerlite setup with the inertia solenoid still in place is supposed to work. It's so far away from how an OEM would do things perhaps my mind had trouble making it compute. The Powerlite has only one large main supply terminal right? rather than two either side of the solenoid that are accessible as is the case on a regular non reduction type pre-engaged starter. The Powerlite has the second terminal that is the direct connection to the motor itself inaccessible and hidden inside. Originally I was thinking that it was a direct feed from the output of the original inertia solenoid to the motor itself whereas in fact it's an indirect feed through the second solenoid on the Powerlite starter.

Still no good and poor design. You have 2 high current high contact resistance solenoids in series when you only need one. The original inertia solenoid is only experiencing anywhere near it's rated current when the starter is keyed off and not when it's keyed on. I expect this may have a detrimental effect on the contacts over time. Dan - you could probably fix your problem temporarily by just installing a new inertia solenoid because the original has probably developed high contact resistance over time when used in this manner.

Again the best solution is still to replace the inertia solenoid with a standard low current automotive relay and use it as a start relay. If someone could post a PDF from the workshop manual of the Lotus starting circuit I'd be happy to annotate it to show how to wire up such a relay.

If you are fussy about originality maybe it's possible to hide the start relay under the dash somewhere? You can still keep the inertia solenoid in place so long as it's modified so the main terminal contacts are permanently bridged.

I agree too with the other poster - Is there really that much wrong with the original Lucas starter? They have never caused me that much grief apart from on occasions suffering from a tooth abutment between the pinion and ring gear. Nothing a quick twirl with a spanner on the end of the armature shaft won't fix! People often put a pinion with an incorrect number of teeth on them which alters the gearing ratio between the pinion and ring gear. There's several types of pinion available.

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 8:21 am
by ericbushby
2cams70
That`s OK, we got there!
We are all on here to learn. This forum has been invaluable to me and I have had explanations of many things that I did not understand before.
The idea is to help each other to enjoy these cars.
Cheers
Eric in Burnley

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 6:18 pm
by billwill
This subject has been covered before on this forum at least once:

lotus-twincam-f39/keeping-solenoid-with-high-torque-starter-t35662.html

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 6:31 pm
by billwill
An original type starter solenoid is essentially the same thing as a high contact-current relay.

Keeping it in circuit and switching the high current to the pre-engaged starter is a good safety feature since otherwise you would have a big fat cable permanently connected to the battery & going down into the depths of the engine compartment where metallic things might fall on it.

If you have a ballasted ignition coil, retaining the original starter solenoid in circuit also means that you do not need to fudge around to provide the boost wire to the ignition coil, it is already there on the original solenoid.

As has been discussed above the solenoid mounted on the pre-engaged starter motor has its own set of high-current contacts inside so the motor will not start to turn until after the starter cog has been thrust into the ring-gear on the flywheel.

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 7:21 pm
by pharriso
For what it's worth I agree 100% with Billwill!

Re: S4 Starting problems

PostPosted: Thu Sep 14, 2017 10:26 pm
by collins_dan
I like to stay as original as possible and if it provides the same function, why not. Mine was removed before I bought the car. Looks like Ray has them. I am guessing he has a mounting bracket as well. Any tips on mounting and wiring appreciated. Thanks all, Dan