wiring harness question

[Movin]

George I think provided a list of things that the white wire goes to. Some of those
are not necessary for the car to run. They could be the problem. If you replace
the fuse with a breaker for a bit there is another genuine ford test you can do,
the wiggle test. With the beaker clicking you wiggle the loom until you find the
spot that makes it quit clicking. Or use the headlight bulb trick, it works like you
tried to do with your test light but the bulb is big enough to supply power to
good items in that circuit. When you disconnect the fuse, unplug your ignition
switch, what ever, something will make the light go out.

For instance if unplugging the switch made it go out you would check each wire
leaving the the plug to see which wire is shorted. Then follow that wire or look it
up in a wiring diagram. We can help with that!

[georgeb]

For the MAIN fuse to blow I believe the short is in the MAIN circuit, which is one white wire coming out of the fusable link box and branching out through splices to 4 or 5 components. You need to isolate this harness by disconnecting it as close to these components as possible. The one at the box and the alt are easy. The ign sw and fuse box might be more difficult. If you have an ATX you will have a condenser fan relay.Just remove the inline fuse. So this harness should not be attached to anything. If your ohmeter or powered test light still shows continuity to ground, you have a short. You need to do this before you proceed any further. No more unwrapping harnesses or disassembly.

[georgeb]

There is another component that is powered by this circuit: The parking light relay which is on the pass side brhind the headlight. You might have already mentioned it. Disconnect it. Also the fusebox has a connector on the back and the ign sw has a connector at the end of the pigtail. You might find some melted insulation in the process of disconnecting these components. If this harness is indeed shorted with these things unhooked you might still be able to avoid swapping harnesses by running your own wires. At least that is what I would do.

[crusher773]

Passing lamp relay, ign switch,alt, have all been disconnected. Still have a short just for kicks I checked and still getting ground on every single fuse in the fusebox. What the heck is an ATX and my fusebox does not have a plug to it. They are all wired straight from the harness into the box.

[georgeb]

ATX is auto trans. There has to be a way to disconnect the fusebox. Once you do, probe any of the white wire ends with the other going to ground. If there is continuity, the harness is bad. Without the fusebox disconnected the test is flawed. If there is no way to unhook fusebox, all the 'hot at all times' fuses can be removed. They are the ones that the MAIN circuit energizes. That should be enough to isolate the MAIN circuit.

[bravekozak]

I only have an 89 wiring diagram. It shows white going from the fusible link through one connector and then splitting to the fuse block where it feeds stop, hazard and room. It also goes to the A/C switch.

[crusher773]

Unless its wrapped in the loom mine does not have a connection to the box.

[georgeb]

My diagram shows a connector at the fusebox but if you say there isn't that holds more weight. To isolate that leg of the white wire circuit, pull the following fuses: Belts, stop, hazard, room, cigar, and tail. Now the white wire circuit should be completely disconnected. Assuming you are using a powered test light, The kind that has a battery and lights up when the leads are touched together, probe any accessable white wire end with the other to ground. If you have an unpowered test light of course this will not work. You need a powered test light or an ohmmeter set to ohms. I gather from one of your earlier posts that you are probing the pos batt terminal and various points and showing voltage. THAT TEST IS WORTHLESS!

[georgeb]

If the harness is not shorted, it can be plugged back in to do the next test. If it is shorted, it can be further isolated by cutting a branch off at a time until the offending section is located. If you are lucky you might get it on the first try. That one branch can be run with your own wire and spliced near the plug. That's what I would do before I would change a harness that might be fixable.