Printable View
Hello all, i have a stock wire harness and rest of the tbi stuff that i removed from an 87 v30 to go into my 78 k20. I looked around but could not find what amp fuses to use on some of the power wires to the ecu and other components. Could someone point me in the right direction. Thanks
This is generally what I use:
10 amp to feed the ECM
10 to 20 amp to feed the injectors (depends on how many injectors)
20 amp to feed most fuel pumps
Take a look at some OEM vehicles that use a similar set-up to what you are using for those circuits you want to fuse. Many diagrams will list the fuses and their specified current rating.
well, it varies. amp draw increases if your wiring is wimpy, and requires tighter fusing, in case of a short, to ensure a fuse blows instead of frying the wire.
the best way to size a fuse for ANY circuit is to use the amp measurment on any common multimeter, on the fuse block terminals themselves (in place of the fuse obviously). preferrably a real shunted amp meter, though.
start the car, operate all connected devices on that circuit to their max, and record actual max amp draw.
then *1.25 for static loads (ecms, whatever) and ~*2 for dynamic loads (stuff with electric motors and solenoids) and you have a perfect fuse size. round up to the nearest fuse size available. rounding up is always a good idea.
when in doubt, 10 amp fuse is usually cool for anything with just digital electronics, 15 for anything with a solenoid (injectors etc) and 20 amps for anything with an electric motor on it (fuel pump etc)
i'm extra careful with proper fuse sizes, dealt with a lot of electrical fires.
So when i pulled the harness i didnt grab the connector that goes on the back of the green buffer for the vss. I think i can make my own connectors for the buffer but i do not know what each terminal on the buffer does. Does anyone have a picture or can tell me what each terminal does. Thanks