For the realm of self disclosure, I will admit I was VERY wrong to do what I am about to describe. Was in a HUGE hurry and was not thinking. VERY VERY boneheaded move on my part... No question! I was in a hurry to get out the door and found that I had a dead battery. Went to jump my 3G 4Runner using wife's Sequoia. Her leads were hooked up correctly and I inadverntly crossed mine leading to 4Runner..... hooking the positive to the negative and negative to the positive. Never felt so stupid in all my life.

So.... Here is what I have replaced so far and here is what I need help on.

1) New Battery- Installed
2) Alternator Fuse- Replaced
3) TPS Sensor- Replaced

Problems now: Dome lights not working, stereo out, in dash clock out. Dome fuse been checked. However, when I go to replaced the 15A fuse for the dome it blows immediately. Is this is short somewhere? Is the entire system fired? Where do I start?

If the fuse is blowing immediately then yes you have a short somewhere. Did you see any magic smoke when this happened? I have seen the wiring inside the harnesses melt and fuse together from such mishaps. You have already isolated it to that fused circuit so start disconnecting things on that circuit( clock/ radio / etc ) Will need wiring diagram I'm sure. If when all consumers are disconnected and the fuse still blows the wiring is shorted to ground. It is possible one of the components is shorted internally which is why I would suggest disconnecting them all first. You may have to start tracing wiring to find the melted / shorted area by pulling back the wiring loom/tape. What year is it? There are wiring diagrams available here on forum I believe but not all years.
Matt

Good advice, except I would start with the radio. Odds are that's it, in my experience. You don't give a year (please put your details in your sig like everybody else when asking for help). So here is 2002 EWD to get you started.

http://tacoma.site40.net/4Runner_96-...emci/023il.pdf


If that's not it, then go to the center jJunction Box and pull the !A and 1F plugs and see if fuse holds. Reconnect one at a time and that will give you a starting point, kinda splits things in half. Plug numbers and location shown here on p. 24:

http://tacoma.site40.net/4Runner_96-...c/relayloc.pdf

Post back with your results (and your dang year!), if you need more help. I'm travelling today, but I''m sure @IBallEngineer will be happy to assist further if I can't, or even if I can. We work that way.

I have a 2000 4runner sr5 that keeps blowing radio fuse, also runs clock, dome light, door buzzer and bright headlights. never worked on electric system, it just started to blow fuses. if I replace fuse will work until I shut off and restart engine....any suggestions? I think its the radio

I did this by mistake in college on my celica. I had issues like you describe for a long time. What I ended up doing, was replacing the entire fuse box in the engine bay. Get on Ebay and buy one and swap the entire thing. I ended up having a short in the actual box that I couldn't diagnosis.

Once I did that, all was well with the vehicle again.

So pull the radio out and see what happens. If it stops it's the radio.

Sorry! Forgot to include that stuff!

1999, 230+ miles, SR5, 4x4

Also, I checked the fuse in the back of the radio and it was good. Would it still create a short?

Possible it could still be inside the radio before its internal fuse. Remove it from the electrical circuit and retest. Then repeat with other easily accessible components in the circuit ( clock, etc. ) , i would suggest this and whatever the durk says. He has helped me with some electrical issue before and is very knowledgeable!

If the short was IN the unit, yes. But just rule it out first, by simply disconnecting the power from the head unit. Since you said it has a fuse, I'm assuming it is not the original radio. The power from the dome light goes to the radio on a Blue/yellow stripe wire, at least it does on an 02. If that is disconnected and the fuse doesn't blow, you found the problem. If it still blows, we will need to direct you to a some connectors at the body ECU, otherwise called driver's side junction block. Disconnect the radio first, that's easy!