Intermittent Loss of Electric Power

[bob hughes]

Hi Guys

I am experiencing a new problem.

When I am driving the car the engine will suddenly stop, I look at the petrol gauge and the needle has returned to position zero.
I turn the ignition key to the off position and try to start it in the usual fashion, but there is no juice at all. The petrol gauge has stopped working and the starter button is dead.

On one of these occasions a passerby helped as I was on a junction. We rolled the car back into a safer position and tried again to no avail, and this time the passerby tried the key and the starter button and thought that there was something up with the ignition switch. After a few minutes passed I tried and got juice so could start it again.

It is possible that the switch could be to blame. That would explain why nothing works, so I have ordered up a new ignition switch and it should arrive today.

Has any one experienced this problem, or have any further thoughts on why this could be happening?



Bob

 

[BobHaskell]

Hey Bob,

Have you checked the battery cutoff switch?

 

[bob hughes]

It is possible that the switch could be to blame, that would explain why nothing works, so I have ordered up a new ignition switch and it should arrive today. Has any one experienced this problem, or have any further thoughts on why this could be

I have just found my testing equipment and checked across the terminals of the ignition switch, it is on the bench, and there appears to be no connection when the switch is on so it looks like problem solved, I will report back when the new switch has arrived and
I have run the car for a while.


Bob

 

[bob hughes]

Hi Bob

That was a good point, as I have just put the car back together after rebuilding the boot, new floor, fuel tank etc. I could not get the car started and it appeared that I had grounded that small wire instead of connecting it to the rear of the cut out switch - a senior moment !!
I think that I am on the right track now, given my update above.


Bob

 

[bob hughes]

Doh!! Looks as if I have had another.senior moment, when I tested the ignition switch I just put the probes on the screws - they were a tad rusty. Placing the probes onto the brass threads gave a good connection across the switch. As the problem is intermittent the switch may still be the problem . On the other hand Bob may be right with the battery switch. I will check both when the next failure occurs.

Cheers

Bob

 

[Michael Oritt]

Bob--

Glad you got squared away and it was the ignition and not the battery switch.

That being said, someone from this list--and only minimal skills would be required--could travel the nation offering to tear out any of the original shutoff switches and install a decent substitute, cutting away the grounding wire that is the source of some many peoples' problems. He or she would make a fortune and do a good deed in the process!.

I tore mine out years ago and installed a Hella marine-grade substitute with heavy duty internals and externals, all tinned against corrosion. It does not have a circuit for grounding the ignition, and though some think the theft protection offered by a grounded coil is important, present-day thieves who have designs on your Healey will probably come equipped with a rollback, making this feature pretty irrelevant. But if coil or alternator grounding is important there are lots of switches that have a second circuit.

 

[John Turney]

The main key to battery cutoff switch longevity is to turn off all loads prior to turning the switch off.

 

[BobHaskell]

Bob, if the horns still work when it dies then it's probably not the battery cutoff switch. The horns are not wired through the ignition switch. They're wired to the 50 amp fuse which gets power from the A post on the voltage regulator / starter relay / battery.

 

[bob hughes]

Thanks Bob, a good idea, it could narrow things down a bit


Bob

 

[CraigC]

Note, the following applies to early six cylinder cars and the 100. Since you didn't specify what you have, I stuck to the early cars as I am a 100 owner.

To add to what Bob Haskell, said also try the headlights. Both horn and headlights are "always on" circuits, but pick up their power at different points. Horn circuit gets its power from the "A" terminal of the voltage regulator(same terminal to which the power feed from battery cable terminal of solenoid is connected). Lights, being a "constant load" when on, take their power from terminal A1 of voltage regulator. Ignition switch gets its power from the power feed terminal of light switch. Got to love the Lucas "daisy chain" wiring.

Also check to see if you hear fuel pump running with ignition on.

If both headlights and horn work you have eliminated all battery cables and the master switch.

If neither work, you will need to check battery and both the ground circuit and power supply all the way to "A" on the regulator. On a 100, one can do that by simply using the manual push on the back of starter solenoid. I know that is near impossible on a six cylinder car, but if you can always try.

If horn works and headlights do not, check for power at A1 of regulator. If good, proceed to check the power connection at headlight switch. Make certain the connection is tight, and do the same at the ignition switch. If no power at A1, check the wire from A1 to starter solenoid.

By the way, you should check to see if the intermittent failure has gone away during testing, by occasionally trying to start the car or just turning ignition on and checking for fuel gauge operation.

The point here is that the problem area, and thus the area(s) that need testing, can be narrowed considerably before you even get out of the car or get any tools.

 

[bob hughes]

Thank Craig, all good stuff, all this reminds me of the time I had a.failure in the low tension wire from the coil to the distributor, it was ok when the engine was cold, but after warming up the connection would fail.
Cheers

Bob9

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[bob hughes]

Well the new ignition switch body arrived but the lock barrel kept coming out no matter which way the key was turned, it looks as if I will need to purchase a whole new assembly keys and all, if indeed that is the cause of my problem. I cleaned up the terminals on the old switch installed the lock and fitted it to the car. Took it out for a brief drive and the car behaved itself. Looks as if this is going to be a long journey to find out the root cause of my problem. I will keep you posted on any developments. Thanks for all your helpful comments.

Cheers

Bob

 

[BobHaskell]

There should be a spring loaded pin in the barrel that slips into a hole in the lock to keep the barrel in place.

 

[bob hughes]

Bob
There was, and you could hear it click into position, it still came back out with the key, so I returned it the switch body After extensive searching I think that the starter motor is partially to blame. The car is in my garage and has not moved for a few weeks, I tried to start it on Friday, it turned the engine over for a bit then stated to chatter and everything went South, I think that has to do with the inbuilt starter solenoid ( it is a WOSP starter) talking to Bill Rawles, I have attempted to clean it up in the past but obviously did not do a good job. I got my tester out and started to check a few things and everything seemed ok, after a while I turned the ignition switch on, every thing that should light up or move came on and even the horn worked a bit, I did not try to start it again but turned the lights on - Immediately the electrics cut out and the fuel gauge fell back to zero, turned the lights off and and the electrics on the dash were up and running again. At that point I left it. I have looked at it today and again switched the ignition on, all ok then I put the lights on, all ok. Turned everything off and put the lights on - all ok. The only thing I did not do was start it up. What bugs me is, if there is a problem with the Wosp starter, when I did manage to start it, why did the electrics go and the car stop when I was driving it.
I am in the middle of some home decorating which the catering management has decreed must be finished before I can go out and play changing starter motors. I will post an update ASAP




Bob

 

[Dandare]

Once again Bob it's management which determines the future of our cars!

Danny

 

[bob hughes]

OK Guys, finally cracked it I think.

I had a telephone discussion with my local ish Guru Bill Rawles, I explained the symptoms and he straight away pin pointed the fact that I had a dry joint in the system somewhere, and to check the battery connections and particularly the earth from the battery and also the strap to the engine from the chassis. He said that he would put money on it being the strap as they tend to fray and the connections break down.
The battery connections and the earth had already been checked so I jacked the old girl up and went straight to the strap, it was sound but I removed it anyway and cleaned up all the contact surfaces including the strap, the nut, bolt and washers. Put it all back together, dropped the old girl to the deck and switched the ignition on with some intrepidation, hit the starter button. It did not fire up immediately, but it did not 'short' out either, after several attempts she fired up and so I backed out of the garage and stopped the engine to close the doors, on starting again there was a click and nothing, but after switching of and starting up again the engine fired and I took it for an 18 mile round trip with a stop half way around with out any problems. Such and easy fix to a nasty problem, I am now the proud owner of three starter motors (one original) and two gear reduction jobs and several solenoids. This new starter motor is a Powerlite and is much quieter than the Wosp and has a nice whistling sound on starting up.
I think that I should start up my own spares business



Bob

 

[jcw67spitfire]

Glad you got it on the road. I got a group started on electric upgrades of all sizes and will put out invites if anyone is interested.

 

[gonzo]

Good to learn that a simple fix solved the problem. Where did you source the Powerlite starter motor?

 

[bob hughes]

Good to learn that a simple fix solved the problem. Where did you source the Powerlite starter motor?

Direct from the manufacture, they have an offer on for club members, I am not sure if it can apply to those on the other side of the pond, but you could always phone them.