[Hsmithyy]

The 15amp fuse under the drivers side of the dash keep blowing I've tested the motor with a separate battery and everything seems to be okay. Just wondering if anyone has had this issue and knows the quick solution. I could fault find along the whole circuit but just trying to save doing that. Cheers. 94 g16b swb

[fordem]

How does making the assumption that the fault on your car is the same as it was on someone else's save anything? When does the fuse blow - immediately you switch the ignition on? immediately you switch the wiper on? after the wiper has been running for a while?

When you tested the motor did you test for current draw with the linkage attached and the blades on screen?

[Hsmithyy]

Because if they have had the same problem they could have a simple solution that I could save me time? I guess?
The fuse blows after the wipers have been running for about 3 minutes. And no I didnt test current draw but I did test with a 15a fuse inline and it ran for alot longer the 3 minutes and didnt blow inline fuse. Should I test current draw to eliminate motor fault?

[fordem]

What's your knowledge/experience troubleshooting electrical problems like? Fuses are fire protection devices, they fail when excessive current is drawn, if the current draw is marginally higher than the fuse rating, it may take several minutes for the fuse to fail, if it's several times greater than the fuse rating it will fail immediately. Replacing a fuse with one with a larger rating is an excellent way to burn things up (or down).

The fact that the fuse does not fail immediately suggests that you do not have a wiring fault (although it is possible for wiring faults to be intermittent) and whilst I don't recommend using larger fuses, the fact that the larger fuse did not fail, pretty much confirms that the fault is not an intermittent wiring one.

With regard testing current draw, I doubt that you can find any data that will tell you exactly what the motor should draw, but a measurement of actual draw, both loaded and unloaded, and a judicious comparison of that to the fuse rating may give you some idea of where the fault lies. I would expect full load draw to be not more than half of the fuse rating.

Please note the constant references to load - the drag of the blades on the screen is considerable, and the current drawn will increase under those circumstances, a binding linkage will also have a similar effect - the motor and linkage is where I would be focusing my attention, I think it's highly unlikely to be a wiring fault.