So, having got the engine more or less running OK (with Hylomar on the head gaskets), I move on to exploring the electrics, or at least the serviceability or otherwise of the dynamo, whilst waiting for the welds and paint on the wings to cool / dry.
Dead easy! I have got a copy of the 1930-31 Wiring Diagram.
Except, the diagram shows what appears to be a separate 'earth' connection from the top right-hand corner of the cut-out, and my cut-out has two terminals, one labelled 'batt'.
If the 'batt' terminal should be connected to the battery, then why not connect it to the 'A' terminal on the dynamo as this is connected to the battery (via the ammeter) anyway?
If the apparent 'earth' connection should go to 'earth' (well chassis anyway) then why not make it an internal connection wihin the cut-out?
As usual. . . . .
Electrification
-
ian Howell
- Posts: 963
- Joined: Thu Feb 09, 2006 10:46 am
- Your interest in the forum: From 1962 to '63, CA Bradord LLG 125 (Repaired and used).
From 1966 to '67 Black deLuxe Javelin LDF 738 (Scrapped with broken chassis)
From 1967 to '87 Black de Luxe Javelin MKC 1 (later 6469TU). (Sold as non-runner with tons of spares, 1987)
From about 1980 to '87 ex WD Jowett stationary engine. (Sold on)
From 1966 to present, 1930 Long Four Fabric Saloon, Dark Blue / Black.
Taken in a part-repaired state to the 2010 Centenary Rally, returned to a roadworthy state by 2013. - Given Name: Ian
- Location: Eastbourne, East Sussex, England
- Contact:
Electrification
The devil is in the detail!
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Tony Fearn
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- Your interest in the forum: Early pre-wars. Owner of 1933 'Flying Fox' 'Sarah Jane, and 1934 Short saloon 'Mary Ellen'.
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- Location: Clayton le Moors, Lancashire, the Premier County in the British Isles!!
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Robin Fairservice
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- Your interest in the forum: Learning about Jowett cars
- Given Name: ROBIN
- Location: Prince George, BC, Canada
Pre War electrics
Knowing nothing about pre war Jowett electrics, I would suggest the the terminal labelled Batt should be connected to the battery, because if the dynamo happened to fail, then you might not have any electrics to the remainder of the system.
My suggestion is to try and follow the wiring with the diagram in one hand and a meter in the other. I also have a collection of pieces of wire with alligator connections on at each end to check for continuity between ends of wires wfich should be continous, and a wire connected to a 9 volt battery to check to see if a voltage actually gets to where it should. If you have a battery installed then a wire connected to a bulb is also handy, for you can then find out if you actually power where you should.
My suggestion is to try and follow the wiring with the diagram in one hand and a meter in the other. I also have a collection of pieces of wire with alligator connections on at each end to check for continuity between ends of wires wfich should be continous, and a wire connected to a 9 volt battery to check to see if a voltage actually gets to where it should. If you have a battery installed then a wire connected to a bulb is also handy, for you can then find out if you actually power where you should.
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Tony Fearn
- Posts: 1743
- Joined: Thu Feb 09, 2006 5:33 pm
- Your interest in the forum: Early pre-wars. Owner of 1933 'Flying Fox' 'Sarah Jane, and 1934 Short saloon 'Mary Ellen'.
- Given Name: Anthony
- Location: Clayton le Moors, Lancashire, the Premier County in the British Isles!!
Pre-war electrics.
Hello again Ian.
Still don't know about Jowett electrics from an academic viewpoint, but I re-wired 'Sarah Jane' and as yet she hasn't gone up in flames. (Hope I don't regret saying that)!!
I've been across to the garage and photographed the 1934-type cut out for you.
It's a third brush type of dynamo that it sits on, and is 12 volts. It has three contacts on the base plate as you will see.
One of the wires from inside the instrument doesn't go to a terminal. It goes through a hole in the base plate and is soldered to the casing of the cut-out.
The cut-out of course is bolted to the dynamo casing which is in contact with the chassis via the engine mounts etc. which I believe is the earthing point.
I've attached photos and a sketch, but do take professional help if you're not sure.
Regards, Tony.
Still don't know about Jowett electrics from an academic viewpoint, but I re-wired 'Sarah Jane' and as yet she hasn't gone up in flames. (Hope I don't regret saying that)!!
I've been across to the garage and photographed the 1934-type cut out for you.
It's a third brush type of dynamo that it sits on, and is 12 volts. It has three contacts on the base plate as you will see.
One of the wires from inside the instrument doesn't go to a terminal. It goes through a hole in the base plate and is soldered to the casing of the cut-out.
The cut-out of course is bolted to the dynamo casing which is in contact with the chassis via the engine mounts etc. which I believe is the earthing point.
I've attached photos and a sketch, but do take professional help if you're not sure.
Regards, Tony.
-
Alastair Gregg
- websitedesign
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D7 CB 6079 CVG 166
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- Location: Corrie, Isle of Arran.
Professional Help
My wife says I need some of that. She says it all the time, but most often when I talk about Jowetts. I'm not too sure what she means! 
Compliments of the Season,
Alastair Gregg
Alastair Gregg
-
ian Howell
- Posts: 963
- Joined: Thu Feb 09, 2006 10:46 am
- Your interest in the forum: From 1962 to '63, CA Bradord LLG 125 (Repaired and used).
From 1966 to '67 Black deLuxe Javelin LDF 738 (Scrapped with broken chassis)
From 1967 to '87 Black de Luxe Javelin MKC 1 (later 6469TU). (Sold as non-runner with tons of spares, 1987)
From about 1980 to '87 ex WD Jowett stationary engine. (Sold on)
From 1966 to present, 1930 Long Four Fabric Saloon, Dark Blue / Black.
Taken in a part-repaired state to the 2010 Centenary Rally, returned to a roadworthy state by 2013. - Given Name: Ian
- Location: Eastbourne, East Sussex, England
- Contact:
First to Tony: - Many thanks for the photo. My cut-outs (I have two the same) are physically different in that the connections are two metal 'lugs' with round headed screws, one at each end. As you say, the third connection is via the bodies of the cut-out and the dynamo to which it is fixed.
Also the covers on mine do not have the metal spring clip, but are held in place by 'dimples' around the base of the cover.
To other contributors: - Many thanks for your trouble and the updates. It's good to feel one has company in these matters!
I found a clearer version of the Jowett wiring diagram in my 1936 Newnes Motor Engineering - Volume II.
DEEP JOY!!
What I took to be an arrow pointing to the battery is in fact an 'earth' symbol lying on its side. This threw me twice: - Once because I am used to different symbols for 'earth' and 'chassis' and once because the earth symbol is usually pointing down.
After a series of toings and froings I suddenly noticed that the ammeter (jury rigged on the engine bulkhead) was reading a charge.
But hey, it all works now and there seems to be at least 10 amps charge in the 'winter' position, but of course that is not (yet) on-the-road conditions!
Next question. What SHOULD be the capacity of the battery? I have a nice moulded LUCAS battery cover, but it may not be the right one for the car.
Obviously, the bigger the better, but there ARE limits.
Oh yes - and how do the cables get from the dynamo (and the ignition for that matter) to the bodywork? Do they just hang in fresh air or should they be attached to something along the way?
Also the covers on mine do not have the metal spring clip, but are held in place by 'dimples' around the base of the cover.
To other contributors: - Many thanks for your trouble and the updates. It's good to feel one has company in these matters!
I found a clearer version of the Jowett wiring diagram in my 1936 Newnes Motor Engineering - Volume II.
DEEP JOY!!
What I took to be an arrow pointing to the battery is in fact an 'earth' symbol lying on its side. This threw me twice: - Once because I am used to different symbols for 'earth' and 'chassis' and once because the earth symbol is usually pointing down.
After a series of toings and froings I suddenly noticed that the ammeter (jury rigged on the engine bulkhead) was reading a charge.
But hey, it all works now and there seems to be at least 10 amps charge in the 'winter' position, but of course that is not (yet) on-the-road conditions!
Next question. What SHOULD be the capacity of the battery? I have a nice moulded LUCAS battery cover, but it may not be the right one for the car.
Obviously, the bigger the better, but there ARE limits.
Oh yes - and how do the cables get from the dynamo (and the ignition for that matter) to the bodywork? Do they just hang in fresh air or should they be attached to something along the way?
The devil is in the detail!