Electrical short - Toyota Nation Forum : Toyota Car and Truck Forums

diggerrigger · 02-08-2011, 01:59 PM

My 1990 SR5 Coupe, 4AFE, has a short that is draining the new battery during periods of no use. The short is not strong enough to light a test light. It does show 13+ volts on an analog voltmeter. A digital ohmmeter reads between 1600 to over 2000 ohms. When I unplug the alternator, this reading drops to 600 ohms. Because unplugging makes a difference, I am thinking bad diode.

In order to test further I wanted to unplug the main fuse to the alternator from the harness at the battery post.. These three fuses are very stubborn. I can't get them to budge. I have exerted a lot of effort to no avail. I guess they are corroded into their sockets. Any tricks to removing them. I soaked them in WD40 but got nowhere.

***SCT*** · 02-08-2011, 02:10 PM

I had blown those fuses out before on another car in the past. It was difficult to remove them. I never removed any from a corolla, but chances are you may be looking to buy replacements.... I broke the ones I had to remove.

90 GP · 02-08-2011, 03:07 PM

Those fusible links are actually screwed in place . The screws make the actual connection between links and the wiring they protect. The bottom of the plastic holder has a section that is hinged and once inside you will see what I mean. You also need to slide down that rubber boot to get to the lower cover.

retiredat44 · 02-08-2011, 04:15 PM

a bad brake light switch can drain a battery...

diggerrigger · 02-08-2011, 04:38 PM

Quote:

Originally Posted by 90 GP

Those fusible links are actually screwed in place . The screws make the actual connection between links and the wiring they protect. The bottom of the plastic holder has a section that is hinged and once inside you will see what I mean. You also need to slide down that rubber boot to get to the lower cover.

Thanks GP. I hope I can easily isolate this short now. I'll report my findings.