Pesky Lectrics

[silverfox]

I've been having intermittent electrical problems with the stag for some time now. Sometimes when I switch off the ignition the car keeps running. To stop it I have to switch off the battery isolator. It sometimes stops immediately and sometimes it keeps running for 20secs or so before stopping. Also sometimes I try to start the car and the ignition lights come on as normal but nothing happens, then when I switch off to retry to start it the ignition lights stay on ( but dimmer than when the ignition is on ). I have renewed the ignition switch but it's still the same. Today I've renewed the isolation switch on the gearbox (type 65 mk 2 auto). Still the same. While changing this switch I noticed the short leads that go from the switch to the 5 pin male connector, (only 4 used ) are in a bad condition, all the insulation is cracking. Does anyone supply this part of the wiring loom. I suppose I could change the connector but the female part that disappears into the car would be difficult to change, working under the car on ramps. Can anyone help please, Terry

[V Mad]

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Hi Terry

Electrics, its all logical provided you don't try to guess whats happening. You need a test lamp/buzzer and you may need a voltmeter.

Firstly, engine running on may be that the iigition isstill getting a supply after you switch off; even disconnecting the battery (dont!)will not guarantee it stops because your alternator is still running. So you need to get a test buzzer on the ignition supply coil + or if electronic measure the supply to the elect module, and check that supply goes off when youy switch off. Best way to kill the engine is to disconnect leads to the coil (either pos or neg).

Secondly, if the ignition is not getting a supply and engine still runs, you probably have a coked up engine that is dieselling, ie red hot carbon ignites the mixture!

Re your bad wiring, you could cut back the wires until you get good wire, then join some new wires on; use heatshrink sleeving to seal and finish off. Joining wires can be soldered if theold wires arenot too oxidised,or you can use crimp straight joints. You should be able to get a new loom from the suppliers, but if you cant letus know.

I hope that helps.

[silverfox]

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Thanks Vmad, I'll check the voltage at the coil tomorrow, it's a bit dark now and the cars outside. I've cut back the leads as far as I dare but the insulation just keeps cracking further back, it really needs replacing but I can't identify the part required anywhere. I don't think I'm suffering from pre-ignition but I'll not rule anything out at this stage, Terry

[V Mad]

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Have you got elec ignition? An idea: maybe the coil is getting powered from the small solenoid wire if there is a fault there?

I think a wiring harness for a BW65 may need to be made up especially, as most stags were type 35. If you cant get one, I can make you one up, but would need to have your old loom to copy.

Cheers

[silverfox]

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Thanks again Chris, yes I've got a petronix electronic ignition system. Which solenoid wire do you mean. The other thing I can't understand is that the gearbox switch has 4 terminals but when you test the switch, only 2 contacts change state, what are the other 2 terminals for. Terry

[StagnJag]

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Reverse light possibly?

[Rubce]

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The other wires are for the overdrive facility which of course your car does not have seeing as it is an auto.

Bruce

[Guest]

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Don't talk to me about pesky lectrics....I am now officially getting annoyed with mine :X

Hope you get yours sorted though.

[marshman]

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silverfox wrote:

The other thing I can't understand is that the gearbox switch has 4 terminals but when you test the switch, only 2 contacts change state, what are the other 2 terminals for. Terry

Two wires go to the switch contacts for the starter inhibit and the other two are for the reversing lights, at least they are on a BW35 inhibitor switch.

To me the problem seems to be an intermittant feed to the switched ignition wire from some other unswitched 12v supply. If you are saying that the insulation on the wires going to the inhibit switch are brittle and breaking off I would put money on the same being true for the wires in the engine bay between the bulkhead and the engine block - ignition/coil feed, oil light etc. On the MK1 the main positive lead from the battery is attached to a stud on the bulkhead in this region so it is conceivable that if the insulation has deteriorated and broken off of these wires then they could be making intermittent contact which could explain the symptoms you describe.

In any case given the condition of the wires you have found alread I would check them as a matter of course.

Roger

[Rubce]

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piscean57 wrote:

Don't talk to me about pesky lectrics....I am now officially getting annoyed with mine :X

Hope you get yours sorted though.

Have you ever considered simply rewiring the car? Its easier than you think and you will fully understand how the entire system works by the time you have finished.

Bruce

[Guest]

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My thinking hadn't got quite that far advanced Bruce but it's certainly something to consider.

The car is at the garage and we are reconditioning the starter motor (needs doing but not the source of the problem) and then swapping coils - again - to see what happens. Currently it seems tobe getting fuel better than before but not sparking well - the garage think I shoudl bin the Mallory Twin point dizzy and revert to a simple single point one.

[V Mad]

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silverfox wrote:

Thanks again Chris, yes I've got a petronix electronic ignition system. Which solenoid wire do you mean.

I was thinking of the thin wire that supplies full volts to the coil on cranking (this is a ballast bypass). But since you have electronic ignition, I am not sure if this wire will still be connected.

[silverfox]

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Thanks for all the replies lads. The reason I questioned the other 2 connections on the switch is that when you operate the switch the terminals stay open circuit so I don't see how they can be for the reversing lights although this would seem to be logical. The reversing lights have never worked by the way and I have not investigated them. I would love to rewire the car but other than a motorbike it's my only transport. Can complete wiring looms be purchased?
The coil is 6 volt Chris, with a ballast resistor wire, 12volt to start and then 6 to run. Thanks again Terry

[V Mad]

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silverfox wrote:

.Can complete wiring looms be purchased?

Rimmers usually have the most comprehensive stock, but I cant see a BW65 loom there.

Specialist loom makers exist which may make one to copy your loom, but one-offs are not cheap.

[silverfox]

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Just to update everyone, switched the ignition on and off repeatedly until the fault appeared. (Don't you just love it when that happens, you've got a fault but when you want to test for it you can't reproduce it. ) Anyway, finally got fault to stay on ie ignition lights on dim with ignition off. Measured voltage at coil and found 4.5volts. Removed fuses one at a time, fault disappeared with No2 fuse removed. This is described in the manual as "ignition control", so no surprise that the fault disappeared as probably a short from another circuit is part powering his circuit. Reproduced fault again and continued removing fuses one by one. Finally found fuse No 11 removed fault. This is supply to heater blower although it also supplies heated rear window, ( no hard top fitted }. Left this fuse out and car starts an stops normally. However the heater blower still works in both positions at slow speed. Thinking back to when I bought the car 12 months ago the heater fuse was missing, I wonder why. I've obviously still got a short or shorts somewhere on the car but where to start and still keep the car running. Anyway it's given me a bit of breathing space but I think I'll wait for the weather to improve. Thanks for all your help, Terry