Fuse Blows when diagramed wiring is used on GMP125-5
I use 3A and 5A fuses. Wired everything just as it is in the service manual and it blows a fuse almost everytime. I've tried variations of grounding...I know the unit is good, but am baffled. Was able to get it to run the cooling system but it wound up bypassing the heating system. it's almost like it's telling me "you can only have one or the other bubba!"
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Re: Fuse Blows when diagramed wiring is used on GMP125-5
I would check your thermastat wiring if you blow the fuse you have a dead short those fuses are saving you alot of money. remove all wires from terminals for t stat on furnance and jump between r and w if it works your problem is in wiring ..........
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This can be caused be either a short in the wiring, loose connection on the board,or a low voltage connection not secure on the board. Check all connections to make sure they are tight and secure. Let me know what you find.
You can take each thermostat wire off the control board and use a ohm meter and test to ground, should not have any resistance. Another way is turn off power take each wire off the board, then place one wire at back on the control board terminals ome at a time, untill the one you get to the one that blows the fuse. If the wires check out good sometimes the thermostat itself can have a internal short and cause the fuse to blow.
Go to Autozone.com and register your car for free. You can then look at Diagrams and your Fusebox layout. You can print the results or use a magnify feature to enlarge what you need. If you do not have a printer, use the one at a Library.
Your heater draws the current more than normal causing your fuse to blown. Check the current draws of your heater by using AM meter then compare to your manual. Apparently the problem is on your heater elements. It may deteriorated over time. Please replace the heaters elements and get it serviced.
disconnect the thernostat wires from the control board. Put a jumper wire between R & G put door back on and turn on power. Blower motor
should run, if it blows the fuse then you have a direct short between R &
G at the board. Do this with R and W(heat) and R & Y(cool).
By disconnecting the thermostat wires and reinserting them make sure that they do not touch when inserted into each terminal. If it still blows
that little 3amp fuse when jumpering between each sequence as mentioned above, then I think your board is bad. When Jumpering out the Y terminal you will have to have the AC wires still hooked up. If it
blows the fuse in that sequence. Disconnect the wires out at the condensor.
The error can be caused by the high limit sensing overheating and cutting off. In that case the thermal fuse may not blow. The high limit can be reset tripping circuit breaker and allowing the unit to cool down with power off.
If that does not work , then the thermo fuse has blown
In fact tis unit has a thermo fuse. (refer to manual).The thermal fuse can be tested reading continuity. If thermal fuse has blown, then replace the the thermo fuse. If the thermo fuse blows again, then there is a condition causing overheating.
Check the breakers on the unit How many KW--electric heat? Check to see if you have the right wires wired up to the correct breaker cause some units have 40---and ---60 ---amps breakers and your thickest wire could be wired to the 40-amp breakers,, (some 5 KW pullls 19-23 amps respectably some breakers have 7.5 KW heat stips and pulls more and if the wire size can,t cary the amps, then all you have to do is reduce a heat strip.
if it is the fuse on the furnace board,disconnect all low voltage wires to r-g-w-y-c.make sure you label where they go.jump out red to white if unit comes on and runs,chances are you have a bad t-stat wire or tstat.
when a fuse blows, its telling you that theres a fault. this could be a loose or broken wire.
or alternatively, the fuse rating is too low. you could check the wires are tight. and also possibly try fitting a 5 amp fuse. check first that the fuse is rated correctly for the appliance. usually 3-5 or 13 Amps.