7.5 guage fuse troubleshooting

[laotionracer101]

My 1987 mk3 7mge 5speed with sports package keeps blowing the 7.5 gauge fuse as soon as the key is turned over, after the car is started a fuse can be put in without consequence. I have unplugged the heater control unit, defrost switch and wiring on the window, completely removed the cruise control actuater, and it is still blowing. When I checked the Load referance to see all possible loads on the tsrm It didnt seem to include the power window circuit (which isnt working). I have actually hooked up a sealed lamp in place of the fuse to tell when (and if) i found the right circuit, It stays luminated even when the car is running. I need some help here my fellow supramanian's. No heater Reaaaaally blows. :nono:

 

[Satan]

Check the wires on the cigarette lighter, as well as try without the lighter in the socket. The gauge fuse seems to be tied to a few "unexpected" things, like the cigarette lighter. Have you installed aftermarket gauges or any wiring work recently?

 

[laotionracer101]

All interior wiring is factory, save for the radio (which still works) I have removed the cigarette lighter entirely. Do you know of any source that will show the definite wiring? Having unknown factors on the fuse load is a headache in itself.

 

[jetjock]

...When I checked the Load reference to see all possible loads on the tsrm It didn't seem to include the power window circuit (which isn't working)...

Power Main Relay = Power Windows

 

[3p141592654]

The online TEWD should help you isolate the loads

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=032

some possibilities are the tail light failure indicator circuit, check engine light circuit, the airbag circuit, the seatbelt warning circuit, ABS lamp. All of those are active at startup, but then go dark under normal conditions.

I would start with the light failure circuit, since that box is in the back and is known to fail after exposure to water from a hatch seal leak.