increasing multimeter fuse rating

[12vshocker]

i was wondering why this is a bad idea or if it's a good idea(pretty sure it's not)

Last week I repaired a vehicle with failed glow plugs, to test the plugs I just did a resistance test, I currently don't own a stand alone amp meter, I have an amp clamp but the wiring wasn't very accessible. It did leave me thinking if a increased the fuse rating in my amp clamp to say 30 amps ( it's currently 10amps) I could of tested each glow plug at the multi plug confirming the integrity of the wiring and condition of the glow plug, I was even thinking about putting a mini circuit breaker on the test lead, just in case there was a short,

Please tell me am I a genius or an idiot or just over complicating things

 

[telectrix]

what's the highest range on your clamp meter? a close-up pic would help. a heater plug is about 120 ohms, so that's 10A each. you could just connect each one in turn and measure the current of each.

 

[12vshocker]

The amp clamp and multimeter have a fuse rating of 10amps, the glow plugs I was testing draw 18amps from cold, but what I'm interest in is what's the potential down fall of increasing the fuse rating in the multimeter

 

[telectrix]

meter meets skip.

 

[Des 56]

what's the potential down fall of increasing the fuse rating in the multimeter

meter meets skip.

Experience ?

 

[ruston]

Na he's to old a cat to be 'taken in' (insert your own description) by a kitten.

 

[12vshocker]

Ok so basically it will fry the meter. Guess I'm not a genius then

 

[telectrix]

just buy an AC/DC clamp meter with a higher range.

 

[Pat H]

The fuse in the meter is there to protect the components inside.
Current is normally measured over a large low value resistor.
If you upped the fuse you'd allow more current through the resistor and it would likely blow. Then its for the skip.

 

[12vshocker]

Could you use a shunt resistor in series to get a basic multimeter to measure higher current draw?

 

[12vshocker]

Oh wait that wouldn't work right because you would need to do a volt drop test after the glow plug to get a reading which isn't really possible

 

[telectrix]

your shunt resistor would need to be in parallel with the meter so it drew a proportion of the current. without knowing the meter's internal resistance on each range, the value cannot be calculated.

 

[12vshocker]

In hindsight my question was probably laughable, but your answers were awesome thanks for your help!

 

[ruston]

But is your question how to test a glow plug lol?

 

[12vshocker]

I'd be interested to hear how you would go about testing glow plugs