Rear defrost shorting out

Does anybody have a wiring diagram that covers the rear defrost and heated mirrors, Chilton manual doesn't cover it. Every time I go to use my rear defrost it blows a fuse, which sucks because it's shared with the starter. It's a short to ground somewhere after the switch and only grounds after the switch is turned on with power on. I'm having trouble finding the short because I don't know if I need to chase the defrost wiring or the heated mirror wiring.

What kinda vehicle ? Once you get beyond oil changes and brake jobs, Haynes and Chilton's are worthless. Click over to PacificCoastManuals.com and spend $7.95 for a genuine Jeep Factory Service Manual. Typically, wire harness issues are near the door/tailgate hinges. Use of your factory service manual and volts/ohms multi-meter will speed up your diagnostics.

It's a 98 cherokee limited 4.0. OK I'll check that site out. Thanks

Best $8 I ever spent.

Probe the related circuits, look for shorts to ground, and for lack of continuity from broken wires. Have your helper move the drivers door and the tailgate while you watch the meter.

It's definitely a short to ground. Doing paper trouble shooting their is only one wire that it can be, which goes from the relay to the actual defrost element. So just need to get access to the bundle at the lift gate and repair that wire.