• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

T-Series Anti run on switch.

Share this page

ecurie_ecosse

ecurie_ecosse

Luke Skywalker
Offline
My question on this switch is; should it have continuity all the time?
It seems to be operating with the ignition switched off,the engine takes a long time to stop when ignition turned off.I have replaced the oil pressure switch,but still doesn't want to stop the engine.
My understanding on this switch is that it is energised when the ignition is turned off,then when engine stops the oil pressure drops breaking the circuit and de-energises the anti- run on switch.At all other times it is not energised.

Any suggestions?

Stuart. :cheers:
 
The "anti- run on switch" is just a set of contacts in the ignition switch that make when the ignition is turned off. If the engine runs on, oil pressure will keep the oil pressure switch on and voltage is supplied through the contacts in the ignition switch to the anti - run on valve, which in turn applies a vacuum to the carburetor float bowls via the charcoal canister. For a complete description, go to Paul Hunts web site, Pages of Bee and Vee at: https://www.mgb-stuff.org.uk/ Click on Spanners, then on Fuel and finally running-on.
Cheers,
 
Thanks,David. I've had a look and gained some useful information. I'm using a battery cut-off switch,and with the ignition off,I turn the cut-off switch on.When I do,the anti-run off switch clcks,then when I turn on the ignition,it clicks once more.But when I switch off,the engine doesn't.This morning,when I switched on, the pump filled the carb float bowl and sent fuel into the carbon cannister.So it seems I have a few problems all at the same time.

Stuart. :cheers:
 
Stuart - Sounds like your anti-run on circuit is miswired in some way or the oil pressure switch is shorted in the on position.

As for the carburetor overflow, I would star by checking the floats for flooding and/or the needle valves for wear or debris trapped in them.
Cheers,
 
ecurie_ecosse said:
Any chance the problem could be caused by faulty earthing?

Stuart. :cheers:
Click to expand...

It really pays to read things carefully.....at first glance what I saw was "...faulty earthLing"! LOL
 
ecurie_ecosse said:
The wiring was backwards,I've fixed the anti-run on switch.But,yes,you guessed it.The blighter won't start now. :rolleyes:

Stuart. :cheers:
Click to expand...

Of course, it's not running on now is it?! In other words, it works.
grin.gif
 
Back
Top