TLDR: Is it possible to lose all power to the cabin other than the dome light if the 100 Amp Alternator fuse in the engine compartment is blown?

So I have a weird issue going on with my '98 Camry LE with the 2.2L. My wife said the stereo stopped working and the display panel was just all white instead of whatever color the RGB was supposed to be. I didn't think much of it and thought I'd figure that out later. A day or two later she said it won't crank or anything. Oddly, the driver side radiator fan was turning really slowly. So I checked the (almost brand new) Optima red top I have in there and it said 4.6 volts. I noticed there was no power in the cabin other than the dome light which was very very dim. I jump started the car and moved it up to our driveway as I was planning to change the timing belt and spark plugs anyway.

I charged the battery on a battery charger for several hours while finishing the timing belt / spark plug job. It was back up to 12 volts. After getting everything back together, the car starts and runs fine, however, I still have virtually no power to the cabin. The dome light still comes on albeit half as bright as it should be. I can't shift out of park as the car doesn't know I'm stepping on the brake, the heater blower motor does nothing... I also noticed when the door is open with engine running, the door chime behaves light the key is in the "OFF" or "ACC" position. It doesn't just bing bong a few times then stop per usual.

I had checked all the underhood fuses before jump starting the car and they looked fine. However, today I looked and the 100 amp ALT fuse was blown. The alternator did feel pretty tight when I had it out of the car. It's still the original Toyota one. I'm going to have it rebuilt this week at some point.

I'm wondering, is it possible to lose almost all power to the cabin if that fuse is blown? That seems kind of weird to me, but I'm not sure. Looking at the schematics in the Hayne's manual, it does look like that is possible. It's also confusing that it's behaving the same way as before when the fuse wasn't blown yet.

Thanks for any help in advance!

 

Yes!

Dome light +12V power has a fusible link in the circuit then runs to the positive battery cable. The battery cable has its own fusible link. The interior lights always have power. The various switches such as dome and door just complete the ground circuit to turn the light on. Unless both fuses are blown, dead battery, etc the done light will work.

Exactly what works and what does not on the car? As in headlights, cig lighter, door locks, etc.

Crossing the battery cables when jumping or changing the battery will blow at lot of fuses.

 

Joey, I can start the engine and green illumination ring around the ignition lights up. When the key is turned to on, the airbag light comes on momentarily and I think the "brake" indicator comes on for the parking brake being pulled up, but no other dash lights. Everything else has no power whatsoever other than the dome light and the door chime as far as I can tell. No windows, heater, cig lighter, door locks or anything.

 

As one can see from the wiring diagram the wiring circuits branch off and become complicated. The best way to diagnosis the issue is determining what works and what does not. This limits the number of branch circuits that might have an issue.

The ign key cylinder ring light is powered via the integration relay which is powered by the same source as the dome light. The integration relay is a simple binary semiconductor unit that blends a lot of the electrical items together.

Toyota used several kinds of fuses having different construction. The most common fuse used is the small colored low amperage fuse pushes into the fuse holder. Toyota also high amperage (high power) fuses such as the 30A/40/50A that are much larger in physical size. These fuses are bolted to wiring behind the circuit board they are attached to. One CAN NOT pull them out like the smaller fuses. Access to the back of the board needs to be gained to unbolt them. If blown these fuses are readily available and YouTube has videos on how to change the out.

Check the stop light and taillight operation which assume should work.

Check the hazard lights and horn. These should work as on the same circuit as the dome light.

With ignition key on as to move to start, is the battery/charge light is on? If so does it go off when engine is running? The charging system is on the 100A ALT fuse.

The ignition key is 2 switches ganged together to operate in sync with each other and each having their own separate power source. One switch operates the engine start and items need to keep it running. Its power source is 30A AM2 fuse and from here it runs to a fuse box to connect to the positive battery cable is connected to. This is the same box the 100A fuse is in. This box also has a 50A heater fuse for the climate system.

The positive battery cable runs to this box. Power then branches out. Some of this power is fused by the 100A and 50A fuses while others bypass the fuse completely.

The climate system also is powered by other fuses. For the manual control it’s the 50A HTR, 10A Heater and 10A A/C. For automatic the 10A ECU-B fuse replaces the 10A A/C fuse.

The other ign switch is powered via the 40A AM1 fuse. Recheck cigarette lighter and power outlet sockets. If no power here check the 40A AM1 fuse. Note the AM1 fuse power routes back to same physical box that has the 100A ALT fuse and 50A Heater fuse but is not fused by them. Like the Dome fuse the AM1 fuse goes directly to the connection for the positive battery cable.

Check above items and post back.