Sig 552 Electrical/trigger problem *SOLVED*

[Con Murder]

Before cracking it open again try easing the tension on the but stock screws (one on each side) if your selector switch is stiff.

If you take the gun apart check mechbox.com to do it proper, v3 if your unsure. Assemble and mount the motor and handle before putting the mechbox in the reciever (so much work!) so you can test it out. Some times I have had selector switch problems from over tightening the but stock (sig552) but this sounds like it may be different.

[dubious]

Alright, I've narrowed down the problem to the contacts that connect with the selector plate. they must not be contacting properly when auto is selected (for whatever reason). Does anybody know- are these only here as an additional safety? One comes from the battery, the other goes to the trigger mechanism. When the selector plate is on semi or auto it is designed to jumper the two (i.e. connect the battery to the trigger). Since the trigger already has a mechanical safety, can anyone see a problem in just soldering them together and dodging the extra safety?

[Skladfin]

Your selector gears are misaligned.

TM Sig 552 Disassembly/Reassembly & Upgrade Guide - boards.ie

And if it kept blowing fuses, it's most likely that it could be any of the following:
- a tight shimming
- something got stuck between the gears(If you've never taken apart the gearbox, this is more likely).
- spring is too strong and you kept holding down the trigger

Bottom line is, the motor can not pull the piston back any further due to any of the possible reasons. Therefore the motor continued to draw current(To try harder to pull the piston back) until it blew the fuse. Identify the cause and it will be the solution.

[dubious]

Negative on that one skladfin, it was the contacts on the trigger mechanism not touching the selector plate properly (even with it pushed to its extents) weird problem, but seems to be solved. I'll let you know once i complete assembly

[dubious]

Yep! All better! Works like a charm.