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Discussion Starter · #1 ·
Anyone got a wag on current draws for various accessories (fuel pump,power windows, power trunk, engine cooling fan etc.? I want to power my windows and trunk thriugh the same circuit as my cooling fan. That circuit is intended to power the fan and fuel pump but im using the fuel pump wire to provide power to the windows and trunk. The circuit is protected by a 20A fuse and I have added 15A fuses to protect the windows and trunk.

Thanks
Bud
 

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62restomod said:
Anyone got a wag on current draws for various accessories (fuel pump,power windows, power trunk, engine cooling fan etc.? I want to power my windows and trunk thriugh the same circuit as my cooling fan. That circuit is intended to power the fan and fuel pump but im using the fuel pump wire to provide power to the windows and trunk. The circuit is protected by a 20A fuse and I have added 15A fuses to protect the windows and trunk.

Thanks
Bud
Motors have a high current draw when they start.After they are moving it is a bit lower. Takes more energy to get the thing spinning. As motor speed ramps up, the current draw goes down some and levels of. This is what is refered to as a surge.
Typical fuel pump current would be about 7 amps surge 3-4 amps contiuous
Power window motors 15-18 surge and around 10-12 running
Trunk pulldown motors, 4-5 amp surge 3 ish amp continuous
Cooling fan , 25-35 on a strong fan motor.They can pull a lot of current.

Remember amp times volts = watts. some cooling fans can suck up 600 watts and more, if they are good ones.Thats 50 plus amps.The surge may be 15 % higher to get her started.
Dont confuse that with a worn out cooling fan motor , they can suck up a lot of wattage, but only because they are dragging and ready to burn out.
 

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Just add another fuse block and fuse each system/circuit properly.
You will be glad you did when the power windows blow a fuse but the fuel pump continues to work.
Also, think of all critical engine related circuits separately from the non-critical trunk poper or AC fan.

vicrod
 

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Discussion Starter · #4 ·
Thanks for the replies y'all. My fan is powered through a relay and my fuel pump is on a different circuit(TPI) so the 20A fuse in the main fuse block is currently (pardon the pun) carring the fan relay and a secondary block containing 15A fuses for the window motors (1) and the trunk motor (1). It is certain the fan and one of the other motors will be powered at the same time (fan is hot ign. on) but unlikely I'll have any 2 other motors running at the same time. Given the potential surge during motor start should I up those fuses to 20A? How bout a 30 in the main fuse block and 20 s in the secondary?

Thanks
Bud
 
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