Embarrassing!

antijam

CCCUK Member
To make the most of the present weather I took the '71 out for a rural blast with the top down the other day to blow away a few cobwebs. Returning to our village I suddenly remembered I needed to buy milk. We have a village shop (1) and a village pub (1) and they're conveniently situated next to each other with open parking in front, so I swung nonchalantly (power steering) into a slot in front of the pub to an appreciative audience sitting outside and entered the shop. Milk bought, I slid deftly back into my steed, depressed the clutch, turned the key.....and nothing - nada, zilch, not a peep. Repeat a few times but equally fruitless. Consider a few possibilities....overheated starter?...ineffective clutch safety switch?....dodgy starter switch? Whatever it is, it's not going to get me home now. Exit car and approach the 'appreciative audience' who are now struggling to contain their mirth and ask a couple of local beefy lads if they wouldn't mind 'giving me a push'. It's a short downhill run from the Pub to home and after being pointed in the right direction and rolling slowly downhill I attempt a 'bump' start. Success! car fires up and we travel the quarter mile home without further issue. Taking no chances I drive straight into the garage before killing the ignition. After letting it cool down I attempt a restart on the key (several times) but absolutely no success.
Sitting in the car pondering the problem I suddenly wonder if the battery could be flat. Seems unlikely as it's trickle charged regularly and we've just had a longish run. Anyway, try the horn and turn on the lights - nothing! So, go to remove the battery to put it on charge. I have a screw type battery isolator fitted to make working on electrics more convenient and before unscrewing it I wonder if it could be the source of the problem. I check and it seems pretty tight but applying considerably more force it does tighten one more turn. Has that made a difference? Try a start .... Bingo! - Problem solved!
Stripping the isolator down I discover that the thread starts to bind just before the end of travel, leading me to believe it's properly connected when actually it's not. The contact faces of the two parts show signs of heavy arcing.....

arcing.jpg
...so the joint had obviously been fretting after I thought I'd tightened it and there was enough contact to allow starting when we set off but not when I returned from the shop. I've cleaned up the thread to ensure reliable clamping and hopefully avoid a recurrence.

It may be a while before I show my face in the Pub again though.......😳
 

Chuffer

CCCUK Member
To make the most of the present weather I took the '71 out for a rural blast with the top down the other day to blow away a few cobwebs. Returning to our village I suddenly remembered I needed to buy milk. We have a village shop (1) and a village pub (1) and they're conveniently situated next to each other with open parking in front, so I swung nonchalantly (power steering) into a slot in front of the pub to an appreciative audience sitting outside and entered the shop. Milk bought, I slid deftly back into my steed, depressed the clutch, turned the key.....and nothing - nada, zilch, not a peep. Repeat a few times but equally fruitless. Consider a few possibilities....overheated starter?...ineffective clutch safety switch?....dodgy starter switch? Whatever it is, it's not going to get me home now. Exit car and approach the 'appreciative audience' who are now struggling to contain their mirth and ask a couple of local beefy lads if they wouldn't mind 'giving me a push'. It's a short downhill run from the Pub to home and after being pointed in the right direction and rolling slowly downhill I attempt a 'bump' start. Success! car fires up and we travel the quarter mile home without further issue. Taking no chances I drive straight into the garage before killing the ignition. After letting it cool down I attempt a restart on the key (several times) but absolutely no success.
Sitting in the car pondering the problem I suddenly wonder if the battery could be flat. Seems unlikely as it's trickle charged regularly and we've just had a longish run. Anyway, try the horn and turn on the lights - nothing! So, go to remove the battery to put it on charge. I have a screw type battery isolator fitted to make working on electrics more convenient and before unscrewing it I wonder if it could be the source of the problem. I check and it seems pretty tight but applying considerably more force it does tighten one more turn. Has that made a difference? Try a start .... Bingo! - Problem solved!
Stripping the isolator down I discover that the thread starts to bind just before the end of travel, leading me to believe it's properly connected when actually it's not. The contact faces of the two parts show signs of heavy arcing.....

View attachment 23824
...so the joint had obviously been fretting after I thought I'd tightened it and there was enough contact to allow starting when we set off but not when I returned from the shop. I've cleaned up the thread to ensure reliable clamping and hopefully avoid a recurrence.

It may be a while before I show my face in the Pub again though.......😳
The same thing happened to Mike Lacey`s resto mod C2 on Sunday before last so missed out on joining a club display at Rushden Hall Park . He drove out his garage ok . Switched off and went in the house , came out , click , click , no start !! Turned out to be same dodgy connection on the problem on the isolator . You were lucky to live down hill from a bunch of drunken car pushers !!
 

Roscobbc

Moderator
I had to replace the same item on mine some years back - exactly the same issue, arcing and eroding metal away.....it would get very hot too due on extended cranking due to reduced surface contact with all those amps trying to get through......
 

teamzr1

Supporting vendor
To make the most of the present weather I took the '71 out for a rural blast with the top down the other day to blow away a few cobwebs. Returning to our village I suddenly remembered I needed to buy milk. We have a village shop (1) and a village pub (1) and they're conveniently situated next to each other with open parking in front, so I swung nonchalantly (power steering) into a slot in front of the pub to an appreciative audience sitting outside and entered the shop. Milk bought, I slid deftly back into my steed, depressed the clutch, turned the key.....and nothing - nada, zilch, not a peep. Repeat a few times but equally fruitless. Consider a few possibilities....overheated starter?...ineffective clutch safety switch?....dodgy starter switch? Whatever it is, it's not going to get me home now. Exit car and approach the 'appreciative audience' who are now struggling to contain their mirth and ask a couple of local beefy lads if they wouldn't mind 'giving me a push'. It's a short downhill run from the Pub to home and after being pointed in the right direction and rolling slowly downhill I attempt a 'bump' start. Success! car fires up and we travel the quarter mile home without further issue. Taking no chances I drive straight into the garage before killing the ignition. After letting it cool down I attempt a restart on the key (several times) but absolutely no success.
Sitting in the car pondering the problem I suddenly wonder if the battery could be flat. Seems unlikely as it's trickle charged regularly and we've just had a longish run. Anyway, try the horn and turn on the lights - nothing! So, go to remove the battery to put it on charge. I have a screw type battery isolator fitted to make working on electrics more convenient and before unscrewing it I wonder if it could be the source of the problem. I check and it seems pretty tight but applying considerably more force it does tighten one more turn. Has that made a difference? Try a start .... Bingo! - Problem solved!
Stripping the isolator down I discover that the thread starts to bind just before the end of travel, leading me to believe it's properly connected when actually it's not. The contact faces of the two parts show signs of heavy arcing.....

...so the joint had obviously been fretting after I thought I'd tightened it and there was enough contact to allow starting when we set off but not when I returned from the shop. I've cleaned up the thread to ensure reliable clamping and hopefully avoid a recurrence.

It may be a while before I show my face in the Pub again though.......😳

Was it also arching at the bottom end ?

arcing.jpg
 

Letank

CCCUK Member
I had a similar issue with a battery isolator upon returning home from the Nationals this year.
I pulled up on the driveway and turned the engine off so not to annoy the neighbours, whilst I unloaded the car and opened the garage door. When I got back into the car, I put my foot on the clutch, turned the key…and nothing. I reached into the battery compartment and felt the battery terminals and isolator screw and all were tight so I assumed I either had a flat battery or a wiring issue??? After pushing the car into the garage by myself (which wasn’t much fun) I’d had enough and went and sulked in the house for the rest of the day 😂. Anyway the next day after work I thought I’d have a better look at it. I got underneath the car to check the main ground cable, and it was loose…but not at the chassis! Then having a proper look in the battery compartment (which is tricky on mine as the aftermarket seatbelt install restricts the lid from opening fully), I could see that the earth cable had completely come away from the isolator switch. I felt like a right idiot for not spotting it right away but at least it was an easy fix! 😄
B6CCD3B1-9591-41B2-957A-87657E168493.jpeg
 
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CaptainK

CCCUK Member
I’ve had this type of quick release terminals on the car for years. They’ve been completely reliable and get unclipped every time the car is back in my garage.
I have those flip up ones as well on my 68. They work well, been on there for almost as long as I've had the car. Got them from Halfords I think.... or maybe Ebay or some such. Can't remember now.
 

antijam

CCCUK Member
Was it also arching at the bottom end ?

View attachment 23828

I think you're right, which means the screw connection to the battery side post was loose as well. Given the high current demand on a battery when starting, screw in type isolators relying on the mechanical advantage gained from the thread pitch and manual torque on the screw to obtain a connection are fundamentally less satisfactory than the basic bolt tightened clamp on a conical battery post. With these not only is more torque applied with a spanner but greater mechanical advantage is obtained by the distance of the bolt from the flex point at the back of the clamp. However the whole point of the isolator is to allow easy disconnection without removing such a clamp.
My feeling is a blade type isolator with a guaranteed clamp force applied and a wiping action connection would be a better solution. Something on these lines perhaps.....
Capture.JPG
 

Roscobbc

Moderator
If you look at the physical contact area of the screw-in type isolator you'll realise it really needs to be screwed-up really tight to stand a chance of transferring all that amperage on engine start-up. On cold start-ups if the car has been standing for a few weeks I'll always turn the engine-over on the starter (without pumping) until I see oil pressure on the gauge - only then 'pumping' the carb. Indicative of how well (or otherwise) the isolator is performing is to feel its temperature!
 

Corvetteville

CCCUK Member
I have one & found it very useful but the construction is a bit suspect, namely the plastic insulator. On mine the tabs holding the upper part broke off. When disconnected it moved around and could even make contact. Maybe this is where the arcing occurs.? I bonded my two pieces together with epoxy, obviously ensuring they were isolated by the insulator. Worked a treat. I think there is a tendancy to only unscrew the green knob a little, otherwise it falls apart.
 

antijam

CCCUK Member
I’ve had this type of quick release terminals on the car for years. They’ve been completely reliable and get unclipped every time the car is back in my garage.

View attachment 23827
I had this type fitted as standard on my ride-on mower. They worked fine although they tended to come apart after several operations - they may just have been el cheapo knockoffs though.
My car came with a practically new side terminal battery and they're obviousy unsuitable for that. One option I guess would be to convert the battery to taper posts like these.....

Capture.JPG
...and then use the clip type connectors?
 

Steven Smith

CCCUK Member
Exactly the same thing happened to my one didn't even last 6 months.
Seems to be a common point of failure.
Replaced it with a more robust switch type, as in the picture. It also has an added "security feature" that handle can be removed.
Screenshot_20230818-163541__01.jpg
 

Mad4slalom

Well-known user
I think you're right, which means the screw connection to the battery side post was loose as well. Given the high current demand on a battery when starting, screw in type isolators relying on the mechanical advantage gained from the thread pitch and manual torque on the screw to obtain a connection are fundamentally less satisfactory than the basic bolt tightened clamp on a conical battery post. With these not only is more torque applied with a spanner but greater mechanical advantage is obtained by the distance of the bolt from the flex point at the back of the clamp. However the whole point of the isolator is to allow easy disconnection without removing such a clamp.
My feeling is a blade type isolator with a guaranteed clamp force applied and a wiping action connection would be a better solution. Something on these lines perhaps.....
View attachment 23857
 

Steven Smith

CCCUK Member
Pretty certain they were from Halfords.

I would like a proper isolator switch like Steves got, but there's not many suitable places to position one on a C3
I now get all my electrical items from 12 volt planet (Auto & Marine Electrical Components & Accessories | 12 Volt Planet) now as got tired of Amazon and eBay stuff being poor quality.
I made a bracket for the isolator and mounted it in a suitable place, then extended the -ve battery cable vie the isolator switch.
You can position the isolator anywhere so long as you get suitable battery cable to compensate for any losses.
 

Mad4slalom

Well-known user
I think you're right, which means the screw connection to the battery side post was loose as well. Given the high current demand on a battery when starting, screw in type isolators relying on the mechanical advantage gained from the thread pitch and manual torque on the screw to obtain a connection are fundamentally less satisfactory than the basic bolt tightened clamp on a conical battery post. With these not only is more torque applied with a spanner but greater mechanical advantage is obtained by the distance of the bolt from the flex point at the back of the clamp. However the whole point of the isolator is to allow easy disconnection without removing such a clamp.
My feeling is a blade type isolator with a guaranteed clamp force applied and a wiping action connection would be a better solution. Something on these lines perhaps.....
View attachment 23857
I have a blade type isolator on my 72, the pO in the states fitted it and advised always to switch off when leaving the car. Protection against shorts/ fires and battery drain and an added security feature. I previously had the big red key type isolators on my beach buggy, of which two failed quite quickly . I was told to get a continuous 100a one which was fine for 3years and still fine when I sold the buggy. 👍
 
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