Noil

I have 97 4runner ltd with auto transmission and a rear elocker, when I started this morning it was already in 4wd hi, and there was a steady tone like the door tone, so I turned the engine off and restarted it and it was fine. I was out town (no off road or really hard bumps), and while out I noticed that my signal lights no longer worked so I pulled off in to a parking lot to see what was going on. Because the parking lot had not been plowed I engaged 4 Hi and found some where to parked, turn the engine off and took the key out of the ignition. Changed the 10 amp fuse for the signal lights and went ahead and started up again tested the signal lights and they worked, went to pull out of park and would not come out of park no matter how hard I pushed the brake or pushed the button (button pushed in fine).

So I tried turning off the motor and restarting and still stuck in park, tried with the key in just the on position and the same thing. Tried putting the 4wd in neutral and disengaging the 4wd button and still stuck in park.

At this point I checked the small fuses under the hood and noticed the rear tail light fuse also a 10 amp had blown, so with the motor off I changed out that fuse and despite my hopes it is still stuck in park.

Then disconnected the positive terminal on the battery waited about 30 seconds and reconnected, still stuck in park.

I tried pressing the rear elocker button the light came on and then I noticed it flashed off and on once and then went out. Running out of any thing else I could try before becoming completely stranded I manually by-passed the netural safety switch by accessing the switch by the shifter lever, that allowed me to get out of park however the transmission would not engage in any gear, acting as if it were still in park.

When I tried to put it the shifter back into park it would not go it did a short little grinding and I immediately did not push forward put it back into neutral and turned off the motor at which time I was able to put the shifter back into park.

It is currently still in the parking lot as I had to get someone come and pick me up.

Anyone got any ideas?

Noil

mt_goat

Do the brake lights work? If not, it might be a bad brake pedal switch.

waskillywabbit

iTrader: (-1)

Trailer hitch wiring likes to short out brake lights and blow the fuse. If your brake lights don't work it won't let you shift out of park unless you pop that little tab off by the auto shifter and push that button/tab in to release it.

:wabbit2:

Noil

Hey, thanks for the reply I went back to the parking lot where it left me stranded, I replaced the tail light fuse again, with engine off brake lights work, engine on brake lights work. Oddly enough I didn't realize when it was day light, the gauge lights and tail lights do not work when the light switch is turned on does not matter if engine is running or not running. I checked the gauge light fuse which was good but just in case I replaced it anyway and still no lights. Brake lights still worked after turning lights on and worked after turning them off.

I also seem to be unable at all to put the shifter in to park without a grind like before I barely touched it and turned off the engine to put into park. Also now since it has sit I can not switch between 4 low or 4 hi without grinding.

Also now when I engaged the rear diff the ABS light comes on with a steady Rear Diff light that stays on this time.

Pressing the 4wd button to disengage 4wd does nothing 4wd light remains on (not flashing).

Having read several people with the issue of blowing tail light fuses that were attributed to a bad trailer harness or a trailer harness with debris in the plug I cleaned it as much as I could, maybe the tail light fuse is coincidence but somehow I don't think so.

Noil

I tried that, but wouldn't engage the transmission, no gears and now it won't let me put it back in park with the engine running. Would not think that there is a linkage issue as it was the 2nd trip of the day. And with the switch by-passed it shifts fine. 4wd on the other hand now won't shift. This time when I moved the shift lever I didn't have to hit by-pass I assume that is because I had brake lights this time around.

Thanks for the idea, I looked to see if I could unplug the whole trailer harness but it disappeared up into the body. Being dark, 24 F, with freezing rain, sleet and snow I didn't pursue following the trailer harness further tonight. I will look into following it back to see if there is a plug to unhook it.

Noil

OK, I have an update for everyone, this morning being a bit more level headed and having done a tonne of reading on the electrical components of the 4runner, it appeared the ECU-B fuse was being the likely culprit.

So this morning I took my other Toyota truck back to the 4Runner I pulled the ECU-B fuse, even though it looked fine I put in a 5 amp fuse because I didn't have a 7.5 amp, started it up and like magic the 4wd disengaged and I had gears in the transmission.

Now that I am back in the driveway with it I can tinker with it. I still don't have gauge lights and keep popping the tail light fuse, which so far I have eliminated the tail light bulbs because I took them out and still popping the fuse. I suspect it is in the factory trailer harness.

Does anyone have an idea how to gain access to the trailer harness once it goes up through the rear cargo floor?

Thanks for all the help so far!

Noil

One other thing ... I have replaced the 5 amp fuse with the proper 7.5 amp fuse and no difference to the current no gauge lights.

mt_goat

Maybe pull up the carpet.

Nervo19

The trailer harness for my 2000 4Runner was added by a trailer hitch company. They did use the Toyota trailer wiring harness. Not sure if yours is factory or whatever. Anyway the wiring is accessable from the driver's side rear cubby strorage compartment.

Thanks for taking the time to update your thread. I once had a problem getting out of 4WD and next day couldn't get it out of Park. Not sure what I did but it shifted fine the next a.m.

Nelsonmd

So if pulling and replacing the fuse seemed to solve at least part of the problem, then it sounds like you have an issue with the fuse or fusebox, and a bad harness may only be part of it.

If the original 7.5 fuse was good, then could there have been some corrosion or oxidation causing the fuse to lose connection? Pulling it out and putting a new one in could have scraped some corrosion off and re-established the connection.

Noil

Thank you everyone who has helped, I got the problem fixed. The trailer wire harness as far as I could tell looked stock Toyota, the previous owner went all out on the Limited edition with all the bells and whistles.

For me the harness went up into the rear cargo floor and then over to a plug behind the cargo panel on the drivers' side. Once I got the panel mostly freed I simply unplugged the trailer harness and put in new fuse for the tail lights and everything was good as gold.

Have had it out twice since unplugging the harness and no more issues. Hopefully this thread will help someone else who has a similar experience in a sudden loss of lights, indicators, and ability to engage the 4wd and transmission.

I've not tested the original 7.5 amp fuse for the ECU-B but Nelsonmd is likely right that the act of removing the fuse was enough to re-establish a connection.

Having learned from this I now make sure there are 7.5 amp fuses in my fuse kit and have a greater appreciation for the ECU-B fuse.

Ron Helmuth

Noil it's people like you who update their threads that make this forum so worthwhile.

You talked it out, which led to you figuring it out, then were kind of enough to share the info with us all so everyone can learn.

I've got quite a bit of experience with that trailer light converter. You can view my threads if you choose to replace that mysterious black box, but it sounds like you possibly have no need for it, however it is sometimes necessary to restore full functionality to your dash and parking lights.

Congrats on figuring it out and thanks again for sharing that info with us.

Noil

Thanks! I may be interested in getting the trailer harness fully resolved and working again. I don't haul a lot of trailers, but you never know when one needs to hook up and haul something.

The next big job for me is going to be replacing the steering rack and pinion which has a small leak on the driver side.

When I had the cargo panel off the back I didn't see any black box device, the harness for the trailer lights went from the hitch up through the floor and over to the tail light where it had a white plug that plugged into the tail light harness.

Is the black box further up the back cargo area?

Ron Helmuth

On a 2000 model it's possible the black box is in the passenger rear cargo corner. On my 99 it was located at the driver's rear corner. Kind of shoved in the corner with some foam padding around it.

Hopkins makes a plug and play replacement. Stay in touch if you need more help.