RESOLVED - Fast left blinker, AND engines "misses" when left blinker on

Hello everyone.

This is Rob from the Lehigh Valley area (Allentown) in eastern Pennsyltucky, and this is my first post.

2003 4Runner, V6, Base Model, no mods, no trailer hitch wiring, all minor and major maintenance and up-keep performed - ~125,000 miles. Yes, I purchased it in 2012 or 2013 with just under 12K miles on it at the time.

I have done some due-dilligence searching the inter-webs to try and find some answers and thoughts on this but have thus far been unsuccessful, so here I am.

Like the title states, this is what happens, and it started two days ago.

While driving on the highway I turned the left blinker on to pass a truck, eased on the gas and then wham, the engine felt like it was misfiring hard.

I eased off the gas, the engine ran normally again and merged back to the right lane.

Went for another pass a few miles later and the same thing happened.

Through some trial and error and perceptive observation I noticed that -

- this happened only when the left blinker was on and fast blinking
- the "R" light was also pulsing brighter at the same rate that the fast left blinker was going

Additional 'testing' of the two observations resulted in the same engine 'misfire'.

Of course, today on a test drive, the left blinker now flashes at its 'normal' rate, the "R" light does not pulse brighter, and engine does not 'misfire' with acceleration.

The left turn signal bulb seems to be working just fine two days ago and today, activated by the turn signal and 4-way flashers. All exterior lights are working / operating fine.

No CEL light or any other warning lights lit up on the dash.

I have an appointment next week at my local and trusted mechanic, but if the vehicle is operating 'normally' he would probably not find any problems with it.

Any thoughts / ideas on this would be greatly appreciated.

Thank you in advance everyone!

Best regards,

Rob

 

There is actually a simple solution to this problem! Stop using your blinkers! Lol.

Seriously, that’s a weird issue, but obviously electrical in nature. I would start tracing the wiring harness to look for chaffing or other damage that is causing it. I’m having a difficult time processing how the blinker could affect the engine, but a short somewhere I guess could cause that.

I actually had an issue in a MKIV Supra I had where the blinker lever when activated in either L or R would cause the car to shut off. Turned out to be chaffed wires in the steering column.
Maybe it’s something along those lines and can be easily fixed with some electrical tape, but, man your issue has me stumped.

 

+1 I was scratching my head the entire time while reading this. I thought the same thing you did "Dude, just stop using the fucking blinker!" What an odd problem.

 

Right!?! I’m thinking there has to be some wires touching in the main harness somewhere that’s making this happen.

I don’t think Toyota made rodent food wiring back in 2003, but I wouldn’t rule out rodent damage either.

 

Perfect! I like the way you think!! Not just a simple solution, but a "free" one too! It's a win-win as 'they' say!!

I'll take a close look at the wiring harnesses tomorrow.

Thank you!

 

No problem man! I’m interested to hear the outcome of this one and what you find.

 

Ohhh, rodent damage!

This is my son's vehicle now, and with him doing a college semester abroad it does not get driven much. Probably only once a week or so to keep the juices flowing a little bit.

Yeah, those rat-bastid squirrels has better watch out!

And yes, I do appreciate the don't use the fucking blinker suggestions! LOL!

 

Another thought as my troubleshooting brain tries to process this…

Given that it is seemingly intermittent for now, it makes me lean toward a loose wire connection but I’m struggling with the whole misfire thing and without seeing a whole vehicle wiring diagram for that year model, I think inspecting the harness is the smart option.

 

Check grounds

 

Dude! Great suggestion, didn’t even cross my mind but you’re absolutely right, something as simple as a broken ground wire could cause some weird shit to happen.

 

OK, I see that everyone that has 'Chimed in" here so far has a "Custom Title", so in keeping with tradition and the high standards here I just updated mine, fittingly, to "FNG".

As the FNG and occasionally the Fucking Dumb Shit, can someone easily let me know where to look to "check the grounds"?

I'll be doing some internet searching while you're all having a good laugh at my expense! LOL!! I crack myself up sometimes!

I did just also just return from looking under the hood with a bright flashlight and did not see anything out of the ordinary, like chewed up wiring and squirrel shit.

Thanks again!!

 

I would say majority of the intermittent electrical issues are crap grounds.

 

All good man!

For the ground locations, they’re all over the truck but with your situation I would start under the hood, there should be one or two on each side of the engine bay and I think two on the firewall. If those are all good and tight, I would start removing panels in the left and right front floor board area just forward of the doors and check there as well. There’s several ground locations under the dash too.

 

I took a good look around the engine bay and found four or five grounds that were all tight/secure and in decent shape, with hardly any to none at all corrosion on the ground itself and the head of the fastener.

I also took it out on the same route that did the other day when the 'issue' presented itself and drove approximately the same speed with the headlights on and off, with high beams on and off, left blinker activated, and the problem did not arise.

For the purposes of trouble-shooting I suppose that I would be helpful if the problem did persist, but I am happy that it's 'gone' for now.

I am still going to bring it into my mechanic next week and ask him to inspect the grounds that I do not have easy access to.

Thanks again for everyone's input!

Have a great weekend!

Cheers!!

 

Go to cause of fast blinker is a blown turn signal light bulb. Next time it happens, check to see if either left front or back is not lighting up. Replace that bulb (or both) and go from there.

 

Don’t forget to check both left side bulbs, and sockets. I’ve seen weird things happen with both bulbs and sockets. A bit of corrosion in the bulb socket can cause resistance issues. I’ve had double filament brake light bulbs break and have a filament fall onto another filament and back-feed the transmission control module causing transmission codes.

 

Thank you for the suggestions!

With it running I just checked all of the exterior bulbs (with blinkers on, hazards on, high beams on and off, etc.), including the fog lights, and they all seem to be working properly. The sockets look o.k. too, as well as the wires leading into them, but I did not pull any bulbs out of them.

The next time the left-turn blinker is blinking 'fast', I will immediately check (as soon as it's safe to do so) to see what if any of the bulbs may not be functioning at that point.

I will still have my mechanic inspect the 'grounds' that I do not have easy / convenient access to, to hopefully eliminate that variable if it looks like it could be the problem.

Regards,

Rob

 

To follow up on Buckaroo above, did you try duplicating with a bulb removed, one at a time, to simulate a failed bulb? Also, have you ever been able to get it to happen while sitting still and engine idling? Or while sitting still with the key in the run position but engine not running? Or have you only seen it while driving?

 

I have tested for the 'fast' left blinker while driving, on and off throttle, and also parked in the driveway with car running and in also w/the car off and with key in the 'accessory' position, and have not been able to 'summon' the fast blinker in any of those scenarios.

I have not pulled the bulbs one at a time, yet, to see what the results may be.

Thak you for the suggestions!

Regards,

Rob

 

Just something else to check. I was driving my car (this is long ago) and went to change lanes. I put on my left turn signal and the engine would lose power right in sync with the turn signal. It turned out to be a bad alternator and almost dead battery. Replaced the alternator, charged up the battery and everything was fine. Just a thought.

 

This is good info. In this case, I would check the alternator brushes. They're so inexpensive (<$20) and simple to replace that you could just decide to replace them anyway. In my world it's a preventive maintenance thing once I have a vehicle reach 180k miles or so.

 

Thank you Rich and Daddy!

With the 4Runner not getting much use in the last five to six months, I did have to jump-start it a handful of times for its ‘keep it running’ drive (usually just a ~30 mile r/t out and back highway drive).

The battery was installed in 12/2020 according to the decal on it, and I am not sure if the alternator is original or not.

With my son still not home from his semester abroad yet and my daughter having just got her learner’s permit, it is now being driven daily, at which point this ‘issue’ has not popped up again.

We may be onto something here, and I will definitely have my mechanic check the battery and alternator / charging system.

Thanks again!

Rob

 

Dropped the 4Runner off for a Wednesday appointment at my local mechanic. . .

He determined that the alternator was bad, and the likely culprit of the odd symptoms as detailed in the OP.

The bulbs, grounds and wiring all looked good.

With the vehicle up on the lift he found a few other items that needed attention -

• The muffler was rotted out in a spot and needed to be replaced.
• One part of the frame has a rust hole through it and needed to be repaired with a metal patch welded over it.
• The brackets securing the gas tank to the frame were badly rusted and needed to be replaced. He said that "The gas tank is literally being held onto the car by a thread. One good bump or a collision of any sort would become a very bad day."
• The skid-plate protecting the fuel tank was rotted out, but we decided that since the vehicle is not taken off-road that it would not be replaced (to save some $'s).

Labor - $615.00
Parts - $1087.39

Total Pain - ~$1.7K

OUCH!

Not in position to replace it with something newer, and my son needs a vehicle for his summer jobs at the college he attends and also getting to and from his internship job.

Nationwide 'asking' prices on all of the popular / common on-line "For Sale" web-sites for this vehicle year and similar mileage range from approx. $8K/9K - $12K/$13K, which made me feel better about not spending more for repairs than the vehicle is 'worth'.

Unfortunately, the vehicle like sat on grass and under trees for the first 10 or 11 years of its life totaling just under 12K miles, the point at which I purchased it, and is likely the reason for some / a lot of the rust.

Hey, "It's only money, right?!" LOL!!

Thanks again for the members of the forum that offered their suggestions, etc.

Happy Father's Day to the dads here!!

Best regards,

Rob

 

I look at it as repairs are cheaper than $50k for a new one. Plus I just like the look of the 4th gen’s.

 

Absolutely!

The vehicle is a 'beast', even in stock trim, and with G-Y DuraTrac's and Falken Wildpeak A/T3's it has been reliable and steadfast transportation on many a ski-trip locally (NE PA) and to all of the New England states.

I am very happy to be able to keep it running in the family vehicle 'fleet' so it can continue to serve my son's adventures along with his friends!

 

I also say that as someone who has surpassed what I paid for my 4runner in maintenance items and fun mods. I think i'm at (or a little over) about what I could sell the vehicle for with everything i've gotten into it now. Doesn't bother me. Reminds me i need to update my 4runner expenses spreadsheet.