Brandon2938

I've been fighting with electrical problems with my 944$runner for a few months now. It started with the battery not charging. I replaced the battery and had the alternator tested at autozone and it tested fine. problem seemed to be resolved for a few weeks but then the starter began to fail. It would start intermittently and often I would need to bang on the starter to get it to work. I also began noticing an occasional hesitation accompanied by the Charge, Brake, and A/T oil temp lights flickering quickly. I replaced the starter and the hesitation/flickering warning lights stopped for a time.

All was fine until a few weeks ago when the problem returned but more severe. When the warning lights flicker the engine skips in sync with the lights. The seems to come and go. I've looked for any exposed wires in the wiring harness and recently repaired a skinned wire connecting to the starter but the problem continues to get worse and is happening more and more frequently. Currently it has progressed to the point that the truck is almost non drivable

The skipping is very erratic there is no pattern to it like there would be with a dead cylinder for example. it also seems to happen in conjunction with bumps in the road. Every time I hit a bump the dash warning lights flicker and the engine stalls and jerks in sync with the flashing dash lights. It has reached the point that the truck will almost completely shut off if I hit bumpy patch in the road or hit a bump or pot hole hard enough.

I've searched around the forums but I have yet to come across a situation quite like this. I'm beyond frustrated and considered lighting it on fire

Please help me before I decide to use my truck as a bbq



Pic of the truck

BioHazard050

Iv'e notcied the warning lights in my '89 runner flickering under heavy acceleration(AKA stomping on the pedal to merge onto the freeway), but never had a hesitation accompany them.

scope103

You've got a broken connection somewhere, probably in the ignition circuit (because the engine cuts out with bumps), but possibly in the main power section (wiring around the engine fuse box). The connection is broken but still touching, until you bump and it comes apart. It's only going to get worse.

I would try lightly tapping on the wiring harness with the engine idling. I'd start near the igniter. Don't go nuts; you don't want to break something that is otherwise okay. This will take a while; good luck!

Brandon2938

Well a little update

I haven't had a chance to do any checks on the truck but today I attempted to limp it to the bank since its a short drive and on the way back a whole new set of problems developed.

While sitting in traffic on the way home I noticed the speedometer jumping around randomly while the truck was not moving. When I began to move the the transmission seemed to slip very badly. The speedometer continued to jump around as well. After I let off the gas the speedometer began working as normal and the transmission also started working better. I got a bit closer to the house and the transmission began to slip again and this time all the gauges totally quit working.

I limped it home in first gear which seemed to work fine but I still had no working gauges at all.

RAD4Runner

Like Scope103 mentioned^^^

You did not say what engine you have, but if 22RE...
Check the 15A engine fuse circuit here for loose connection and beginnings of a short circuit. The engine fuse supplies the combination meter (dash indicators), computers, backup light circuit, and alternator "IG" wire. The backup switch (manual trans), or possibly neutral (A/T) switch, is wired to the tranny. I suggest you check that wire around the tranny for shorts to ground. A mild short may cause voltage to fluctuate. If not fixed it would short completely and blow the engine fuse.

Transmission could be another problem...

Brandon2938

It's a 3.0 with an automatic.

I'm gettingnit towed down to my to my dad's in the morning. I will start checking things when I get there. I'll post some updates along the way if I find anything.

Thank you everyone for the help so far

Brandon2938

I'm pretty sure I tracked down the problem. Turns out the power wire for an amplifier that was installed by the previous owner had a broken fuse holder and it was grounding the battery to the engine block. A little bit of electrical tape and the stalling and flashing lights issue is gone

the next issue was the gauges not working and severe transmission slippage. I checked the fuse panel in the kick panel and found a blown gauge fuse. I replaced it and all of the gauges except the speedometer are now working correctly. I test drove the truck and my check engine light came on and after checking the codes I got a code 42 indicating a failed vehicle speed sensor

I'm going to check all the wiring going to the speed sensor before I buy a replacement since a new one is nearly $300

scope103

RockAuto has an Airtex/Wells Speed sensor for about $190. i didn't know about RockAuto when I replaced mine with a Toyota unit, so I can't tell you anything about longevity.

But even $190 is too much for "spec," so check the wiring to the extent you can. The good news is that 19 years is pretty much the lifetime of that sensor, so I'm betting you need a new one.

mylittlepony1

Glad you figured it out, I would've thought that your alternator was gone. Autozone tests aren't very reliable

Brandon2938

Well the problem has returned.

Driving home last weekend the same dash warning lights began to flicker and the engine is bogging down and losing power again. Occasionally it won't start and the problem is worse than ever now.

RAD4Runner

Checked if your neutral safety switch is wired to engine fuse and if it' shorting to tranny as I mentioned on my post above?^^

Brandon2938

Bump from the dead. I'm still fighting the same problems with the truck. I've replaced the entire engine wiring harness and just replaced the alternator and no luck. I'm still having the exact same problems. Getting pretty desperate and considering just putting it in a shop but I'm.worried it will cost a small fortune. I had given up on the issue for a while and decided to do a 3.4 swap. I've got most of the parts for the swap together but now my other truck has a bad transmission so I have no choice but.to try again to fix my 4runner.


Any ideas what the problem could be. Have any of you had similar experiences? I.found a thread where someone was having similar issues and it was a bad igniter but would that also cause the dash warning lights and interior light to flicker in sync with the engine losing power?

Shady Cadence

There's two ground connectors under the dash between the fuse box and the door opening, above the kick panel. One has two wires, white with black, to twin connectors. The other is just above, two brown to one connector.
Replace these connectors!
Don't look at them, or clean them. Cut them off, crimp new ones on, try the truck.

The white with black wires are for your heater, a/c, dash illumination, aaand....the fuel pump. The brown ones are for the combination meter (ecu driven) and I can't remember what else.

5 minutes and 3 connectors, what have you got to lose?

Brandon2938

Hey

I haven't had a chance to try the fuse connections under the dash yet but I got the truck cranked up and I'm noticing that sitting still the problem starts when the engine is revved up to about 4k rpm. At that point the engine starts breaking up and the lights start flickering. I just added another frame ground from the battery and it's still the same. I'm about to start working on the fuse connections under the dash.

bswarm

I seem to recall one instance where a bad igniter was making the dash lights flicker, but other instances where bad diodes in the alternator were causing dash lights to flicker. Can you hook up a voltmeter to the cigarette lighter and observe voltage when the misfire/dash lights flicker?

Shady Cadence

You'll see the two ground points when you go to the fuse box.

replace them, try the truck.

Brandon2938

94 4runner electrical problems:
Here's a video I made a bit earlier. You can seen the radio restart because of the loss of power. You can also see the dash lights flicker with the loss of power and the here the engine busting up.

Shady Cadence

Have you at least found the ground wires next to your left foot?

Brandon2938

I'm planning on looking that video was recorded earlier. As soon as I get back home going to find and replace the two grounds you said to look for.

Shady Cadence

Whenever seemingly unrelated things act up in unison, you have GOT to have a ground issue.