I had to bug the forum with such a specific question, but I’m really at a loss here. I’m leaving in a few weeks for a long road trip and was hoping to get this squared away ASAP.

I took the 4Runner out on a camping trip this past weekend (Dolly Sods) which involved some extended driving on rough forest roads. After about 10 miles on the FR, the radio began cutting out randomly. It’d turn off, the antenna would go down, then it’d immediately turn back on and antenna would go back up. I figured there was a loose connection somewhere that was getting jostled. I’d never experienced this before - but I hadn’t driven for extended time on rough roads either. On the way home I drove a little more gently on the FR and it only cut out once. I figured I’d have to address the problem sometime in the future, but it wasn’t pressing.

We stopped for lunch in a town about 20 miles east of the Sods. I parked, turned off the truck, then realized I should make an adjustment to my parking job, and went to turn the truck back on. It was completely dead. Didn’t turn. No power locks. No dash lights. No audible ding. Nothing. The only sign of life was that the Security light was blinking and the Scangauge said “scanning”. After a few attempts I popped the hood. The only thing I could think of was that maybe a battery terminal was loose and power had been coming from the alternator. I checked and they weren’t loose at all. I detached the positive terminal, waited 15 seconds, then reattached. After that it started right back up with no problem. Since then the radio hasn’t cut out and it’s not given me any problems.

Any chance the radio issue and power issue are related? Any places I should look for loose connections?

Clean/scuff up your battery terminals good and coat them with conductor grease or spray. Check the body grounds near battery and on firewall, clean/scuff/coat and also one on intake manifold. Bad grounds can do some funky stuff.

I agree with the post above. Also I'm not sure if the roads you were driving on were somewhat wet? It can take a while for moisture to evaporate from certain parts of the engine bay and also if it gets inside the wire itself. I've had similar experiences after going through water. However body grounds sound more likely! After driving through water I went to start my truck only to hear a click and nothing. Just had to keep turning that key untill she turned over and then it was fine. Once it dried out I have yet to have any problems since.

Also might consider getting your alternator tested. Mine had a crack in the bottom of it when I replaced it. Sounds to me like it could possibly be on it's way out. If you have a second vehicle and an hour or two its quick and easy to pop the alternator out and take it to an auto parts store to get tested for the voltage levels.

^This

Thanks for the advice. I'll have some time to check out the grounds and alternator this weekend.

We did get a fair amount of rain recently, but it hadn't been wet for a few days when the issue occurred. I'll keep that in mind though.

I'm dealing with this right now. If I check the body ground next to the battery when it does it I only have 3-4 volts despite the terminals being tight. If I loosen and retighten the negative it will work for a couple days. Going to get some better terminal ends than the red and black universal ones at all the parts stores.

^^^What they said....plus...

How are your cables? Are any of the terminals those devil's spawn bolt-on jobbies? Check the insulation for any bubbling or discoloration, often a sign of crippling corrosion on the inside.

I had the exact same problem on my 2000. Very random so it was hard to track down.

Not sure if 2002’s are wired the same but on mine it turned out to be the heavy gauge white wire coming from the alternator to the under hood fuse box.

Sometimes just slamming the driver’s door would bring the connection back, other times I had to jiggle/twist the white wire to bring the connection back.

The actual connection is under the fuse box, so you have to remove the fuse box to get at it to clean it up.

My last jiggle/twist fix has lasted quite a while but removing the fuse box and checking/cleaning that connection is on my to-do list before the next major trip.

Gary