Hot switch

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SriVik
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Hot switch

Post by SriVik »

Hello ,

hope i can find a solution here. i am experiencing hot switch every time i operate the headlamps. First time when the switch gave away, i changed it to a new switch. It happened again recently. I doubt its the switch anymore. Mine is 1964 push pull switch. Im using new loom and im following original wiring diagram. I believe hot switch means overcurrent passing by the switch. Anybody experienced it before and how to come over this issue?

Thanks
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mobylette
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Re: Hot switch

Post by mobylette »

If the switch is getting hot under normal load, then it will be because of a resistance within the switch. You could test with a meter for load and resistance or just replace with a good quality switch.
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oliver90owner
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Re: Hot switch

Post by oliver90owner »

Excess current or poor quality switch are the possible isues

Reduce the load, fit a better quality switch or fit a relay are the usual remedies.
alanworland
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Re: Hot switch

Post by alanworland »

Not long after I got my Morris I was coming out of the works carpark when the dashboard emitted clouds of smoke - quite alarming!
It was caused by high resistance in the light switch, I seem to remember I was able to dismantle it and after cleaning it all up has given years of service since.
Definitely one to tackle immediately!

Alan
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Sleeper
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Re: Hot switch

Post by Sleeper »

How do the headlights look , bright or dim?
If they're dim you have a high resistance in the wiring somewhere..

John ;-)
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geoberni
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Re: Hot switch

Post by geoberni »

SriVik wrote: Sun Jan 30, 2022 3:25 pm I believe hot switch means overcurrent passing by the switch. Anybody experienced it before and how to come over this issue?

Thanks
Assuming you haven't overloaded the lighting circuit by fitting extra lamps, or having done anything else to the lighting circuit.....


Don't think of it as 'over current'; it's that the switch is not giving as good an electrical path as it should, so some of the current in the circuit, instead of making the headlamps light, is heating the switch up instead.

It's caused by a poor contact surface within the switch.
The current wants to get to the lamps, but grubby contacts in the switch means it has to fight to get through, and that energy used in getting through the switch is heating it up. ...
If the switch can be taken apart, open it up and clean it. If it's sealed, you'll haver to replace it.
Basil the 1955 series II

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SriVik
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Re: Hot switch

Post by SriVik »

Thanks for the answers,

My first light switch was from CW, current one is from ESM. I believe both from the same supplier. Any link for GOOD quality switch??

The switch gets overheated, even after 20-15mins of usage.. Some told me to add a headlight relay and some told me to add a FUSE to protect the switch. Regarding the relay, Im trying to keep the original wiring. Later models have a 10amp in-line fuse to panel wiring. Issit because if this issue. ??

My front sidelights/number plate/and panel lights are LED. Therefore i don’t think its taking so much of power. Im using sealed beam for headlights. No additional fog or spot lights.

I never tried dismantle the switch and give it a good cleaning. But i guess its worth trying. I hope its just the switch.
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geoberni
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Re: Hot switch

Post by geoberni »

Hi


Fuses do not protect, unless they rupture in a fault condition. If you have a fault, then adding a fuse won't make the fault go away.
Adding a relay because of this is just hiding the problem. The switch should cope with the expected current.

The lighting fuse on the latter cars is only on Side, Number Plate and Interior lights, not the headlights.
It's a 10 Amp fuse and all those small lamps should only total about 4.5 amps. The main beam would account for around 9-10 amp, depending on the wattage. So all the lights on would be a bit too much for a typical Multimeter as they are usually limited to 10 Amp.

You either have a faulty switch or the lighting circuit has a problem.
How old is your car wiring?
Has it ever been replaced?

Do you have a Multimeter and are you reasonably confident/competent in it's use?

What you could do to eliminate aspect of the car wiring is to do some basic checks.
All the lighting wiring has inline connectors. Highlighted yellow.
If you connect a Multimeter set up for Amps, in the line to the Light Switch from the Regulator (see Arrow) and separate all the inline connectors, you can then check out each line to see if there is a fault on it. How many amps for each part of the circuit.

If all this has gone completely over your head, you need to find someone who can check it for you. Don't try and 'Wing It' if you don't know what you are doing.
It might possibly be a faulty dip-switch for example...
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Basil the 1955 series II

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SriVik
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Re: Hot switch

Post by SriVik »

Hi

Exactly my concern regarding the fuse. Why its for sidelamp/panel lights only.

My Loom is new, fixed during restoration about a year ago.

I spoke to an another chap, he told me those days parts are HIGH quality, nowadays the quality is a Big question mark. He advised me to get a old switch from scrapyard an try. I think its a great idea.

If it doesn’t work, then i will have to find a electrician. I not going to fiddle around electrics.

Somewhere on net, i found the new light switch is only rated 10A. Not sure how true, Some good information too.

Vik
SriVik
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Re: Hot switch

Post by SriVik »

End of the day, it was a simple issue. I tried to open the switch and replace, The connections at the back was very loose. Really loose until i dint require a screw driver to loosen the cable end. To avoid further issue, i replace it with new switch.

Save my cost from buying relays..

Thanks for all the help guys. Pleasure driving
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