StarMonkee Posted April 8, 2014 Report Share Posted April 8, 2014 Right its been a good while since I've had the need to open a gearbox due to a wiring issue. The old switch was binned (lets just say I abused it on lipos and you know what that can do over a prolonged time period) Just fitted a G&P mosfet switch and am just getting nothing from the gun. Now its probably down to an error on my part, but the motor is fine, got the old loom here hooked up and the motor spins up fine. Now am no electrical engineer but when I connect my multi meter to the motor connectors I can see the current reading as 7.8v on a 7.4v lipo and when I pull the trigger I see the voltage dip. Like I said its been a long time since I've had to do anything on this level and its currently got me scratching my head about what the issue is. Link to post Share on other sites
ED-SKaR Posted April 8, 2014 Report Share Posted April 8, 2014 Take the motor plate off and remove the motor. attach the wires to the motor with the motor sitting on the table outside of the gun attach battery and pull trigger does the motor jump off of the table spin? Link to post Share on other sites
StarMonkee Posted April 8, 2014 Author Report Share Posted April 8, 2014 Nope I get no life from the motor on that loom outside of the gun Link to post Share on other sites
Tinkerton Posted April 8, 2014 Report Share Posted April 8, 2014 But there's definitely power to the motor when you pull the trigger? That's... odd. And the motor works on the old loom? That's even moar odd. Try and test the motor connections with a bulb or something, see if that lights up. Failing that, are there any soldered connections in the new loom? Make sure none of them are dodgy. Link to post Share on other sites
StarMonkee Posted April 8, 2014 Author Report Share Posted April 8, 2014 Just for the info this is the loom in question I currently have it setup on my desk going battery - switch - motor I touch the multi meter to the solder joints on the switch get a 7.8v reading, on the trigger contacts same reading and get the same reading on the motor contact points. But no life from the motor when I bridge the contacts. Methinks I may have got a lemon Link to post Share on other sites
ED-SKaR Posted April 8, 2014 Report Share Posted April 8, 2014 Seems like it's an issue with the mosfet itself... Link to post Share on other sites
DrAlexanderTobacco Posted April 8, 2014 Report Share Posted April 8, 2014 If you've got HSW and a solder gun you could cut it open and take a look. Link to post Share on other sites
StarMonkee Posted April 8, 2014 Author Report Share Posted April 8, 2014 Mini developement : Just noticed while taking readings that the motor is only receiving 0.84v when the terminals are bridged and the fet is getting the full 7.84v so seems the fet is main culprit . Just whipped the heat shrink off the mosfet and bridged the trigger. I was getting 7.8v on the comm wire to the battery negative and 6.9v on the negative motor connector to the battery negative. This is the inside of the fet When putting the multi meter on the legs working from left to right is goes 0.84v 0v 0.01v 6.98v When I do the first leg and the last leg I get 7.8v Link to post Share on other sites
ED-SKaR Posted April 8, 2014 Report Share Posted April 8, 2014 It might just be wired wrong, .84v sounds like command circuit voltage. ooooor you could get yourself a replacement from the shop you got it from, if you've taken it apart you might not be covered by warantee anymore! Link to post Share on other sites
StarMonkee Posted April 8, 2014 Author Report Share Posted April 8, 2014 I got it from ehobby so doubt they'd have done anything really lol Link to post Share on other sites
Recommended Posts
Archived
This topic is now archived and is closed to further replies.