Sounds like you need a little resistance in the place where the multimeter is measuring current (10A fuse in the meter I assume?). That means when you hit the button it happily applied full voltage across the meter and a large current flowed. Based on the 10A fuse blowing I'd say you had probably over 20A. Had there been an igniter there it probably would have worked .
The meter has a very low resistance and will let quite a large current flow if it is otherwise unimpeded. Adding a little resistance in the place where the igniter should be should bring the current back to sensible levels.
Say the meter is 0.1ohm. At 12V you would (discarding other circuit resistance and battery impedance) get 120A of current.
With a 1.2ohm igniter in series, the current comes in at about 10A. Your 10A fuse should take that for quite a few seconds before blowing, but your meter may go overrange temporarily.
If the 10A fuse was not in the meter and the meter is not where I was assuming, let me know!
Given the high currents expected when firing up an igniter it is wise to have a fuse somewhere in your launcher.
The meter has a very low resistance and will let quite a large current flow if it is otherwise unimpeded. Adding a little resistance in the place where the igniter should be should bring the current back to sensible levels.
Say the meter is 0.1ohm. At 12V you would (discarding other circuit resistance and battery impedance) get 120A of current.
With a 1.2ohm igniter in series, the current comes in at about 10A. Your 10A fuse should take that for quite a few seconds before blowing, but your meter may go overrange temporarily.
If the 10A fuse was not in the meter and the meter is not where I was assuming, let me know!
Given the high currents expected when firing up an igniter it is wise to have a fuse somewhere in your launcher.