Kill switch on electric pallet truck

[fizzy]

My electric pallet truck has stopped working.
I thought it was the speed controller. £55 from China.
But just found a weird problem.
24.6v across the 2 lead acid batteries.
23.6v at the speed controller.
Only thing in the way is this kill switch.
Could it have a deliberate voltage dropper in it?
No continuity between the 2 terminals when the switch is activated.

 

[Robotstar5]

Probably oxidised/dirty contacts inside, disconnect the wires and measure the resistance across the switch.

 

[fizzy]

Probably oxidised/dirty contacts inside, disconnect the wires and measure the resistance across the switch.

That's what I am thinking. I see it is screwed together. Will open it up. Perhaps I can save a few quid

 

[Jack_K]

Measure the voltage across it's terminals. Surely it would still work at 23.6v though?

 

[fizzy]

Measure the voltage across it's terminals. Surely it would still work at 23.6v though?

That is my concern. I will bypass the switch to find out.
But it may drop even more under load.

 

[zzr1200]

Burnt contacts would be my guess, voltage is a test, its the amperage you need, try fitting a car battery isolator to test or just join the 2 cables together.

Test the voltage at the motor cables connections under load, to show voltage input, amp-clamp won't show you true power usage due to burnt contacts in E stop.

Pardon our interruption...

 

[fizzy]

Burnt contacts would be my guess, voltage is a test, its the amperage you need, try fitting a car battery isolator to test or just join the 2 cables together.

Test the voltage at the motor cables connections under load, to show voltage input, amp-clamp won't show you true power usage due to burnt contacts in E stop.

Pardon our interruption...

I was going to just bypass it but I was worried the Chinese, being so cunning, had hidden some sort of voltage regulator in there! Bit strange it is EXACTLY 1V less!.

 

[Nomad]

Disconnect the battery and open up the switch before doing anything else - then you can see if it is hiding any electronics trickery (unlikely) or if your problem is just burn contacts inside.
If there's no electrics in there just remove the switch and connect the cables together - then see if it powers up.

Do all the work with the battery disconnected to avoid any surprises

 

[zzr1200]

I was going to just bypass it but I was worried the Chinese, being so cunning, had hidden some sort of voltage regulator in there! Bit strange it is EXACTLY 1V less!.

It'll just be an e-stop/cutout switch, l doubt there's any resistor in there. The battery cutout switch l listed above sometimes comes with another low amperage breaker switch which would be used the cut power to the ignition coil and/or fuel
pump.

I'd connect the main cables together to bypass the E/Stop, then check/compare the battery voltage at the battery terminals and then at the main drive motor terminals with a full load on the truck while moving.

Also check all the other wiring crimped and pin connections for being dirty or loose.