Strange electrical issue with turn signals/cruise control

[Mitchell7877]

Exact issue, my fix.

Had the exact issue, it was the pos uhaul add in trailer harness sending 6 volts from turn signal to brake light. The easiest fix was adding a 1ohm resistor in parallel to my brake light. (Takes up extra resistance in the LED bulb) they are at Walmart in the auto bulb section for cheap. Thanks for helping my diagnose my issue!

 

[4RUNNING2THELAKE]

Same problem/still a problem

My 95 Runner just started kicking the cruise out when using the T/S. I am a T/S believer so I use them all the time! A few years ago, I tried the LED route and found that due to the low resistance, the cruise would kick out. The only thing I have had done prior to the issue showing up is I had a brake light interrupter installed in the third brake light. in my pea sized brain, I cannot find a correlation between that and the T/S kicking out problem. But the problem started the exact next time I used the cruise. I have checked all the lights and there are NO malfunctions in the system. So, I am at loss as to what the problem could be. I will add this one thing: everyone in a while, the cruise will kick out and the cruise light will start blinking. If I turn the system off and then back on, it works perfectly for many many miles before it acts up again. Two things that I have had for some time, without any causing cruise issues. T/S repeaters mounted on both fender wells. Side to side LED brake and T/S light bar.
I am getting ready to do a 3000 mi trip and doing so without cruise, would be a nightmare!

 

[brillo_76]

My 95 Runner just started kicking the cruise out when using the T/S. I am a T/S believer so I use them all the time! A few years ago, I tried the LED route and found that due to the low resistance, the cruise would kick out. The only thing I have had done prior to the issue showing up is I had a brake light interrupter installed in the third brake light. in my pea sized brain, I cannot find a correlation between that and the T/S kicking out problem. But the problem started the exact next time I used the cruise. I have checked all the lights and there are NO malfunctions in the system. So, I am at loss as to what the problem could be. I will add this one thing: everyone in a while, the cruise will kick out and the cruise light will start blinking. If I turn the system off and then back on, it works perfectly for many many miles before it acts up again. Two things that I have had for some time, without any causing cruise issues. T/S repeaters mounted on both fender wells. Side to side LED brake and T/S light bar.

I am getting ready to do a 3000 mi trip and doing so without cruise, would be a nightmare!

Hmm. I not sure how much help we can be as this is the 3rd gen 4runner section. [ 1996 thru 2002] 1995 is a 2nd Gen 4runner.


I would However, verify that your wiring is good and what the factory service manual is testing good tests for cruise control are good.

Does the cruise control and turn signals share anything in common?

On the 3rd gens the stop switch and if it's a manual clutch switch are part of the cruise control system?


I never looked to see if the turn signals have anything in common or not. However, I will.







Sent from my SM-J337V using Tapatalk

 

[turbodudey2]

It’s been discussed to some various degrees of clarity in this thread and a few others. But here is what we know:

The brake light circuit and turn signals are to some extent interconnected. This becomes apparent especially when LED brakes lights are installed or a brake lamp is burned out (most critical of all is the third brake light).

When adding a high resistance LED bulb into the brake light circuit, somehow voltage from the turn signals is fed into the stop lamps. This in turn will turn off the cruise control, and unlock the torque converter. That is why people often observe bouncing or fluctuating RPM when activating the turn signals. (The torque converter unlocks in sync with the turn signals)

If you have made any recent modifications to the stop lamps (especially the third brake light) this is undoubtedly the cause of the turn signal and cruise control interference.

I cannot say why the circuit behaves they way, and it does seem rather odd... but that’s just how it seems to work.

 

[pavelvoivoda]

Hi guys,
I think the problem with the rear lights and cruise control cancel, may come from changing the double wolfram lightbulbs that are originally installed in the brake lights, with LEDs that to do not correspond with the oem wiring harness. The oem bulbs, when you remove the from the sockets, you will observe that they have more contact surfaces, I think 3(when common ground is used) or 4. In the wiring loom, the wires that supply ground and voltage are 4, 2 for ground and 2 for voltage. The order of these 4 wires in the connector is specific the light bulbs structure. One set of ground and live wires is for the bulb's tail light wolfram wire, and the other set is for the bulb's stop light's wolfram wire.

When you switch the bulbs with LEDs, LEDs are voltage oriented, and some manufacturers have designed their LEDs with same contact design as that of the OEM wiring loom, but not all. In their installation instructions, they mention that, if after installing them, one of the stop light or tail lights circuits dont work, removed them and installe them in reverse in the connector. It may work, but not for all car manufacturers.

So the problem comes when you installed a set of LEDs with the wrong harness polarity and common ground. To fix the problem you have to remove the pins from the connectors in the wiring loom and reorder them in the correct order for the new LEDs. Otherwise, a common ground on the LEDs can complete a brake circuit and thus cause а cruise control to register that the brake pedal has been depressed, and cancel the set speed.

The OP's problem may be not be related. The brakes and cruise control circuits are connected. The blinkers and cruise control circuits are not.

The OPs problem may come from maybe a secondary alarm being connected to the blinkers and could be connected to the cruise control circuit to be fed 12v.

Depending on the year of the 4runner, there are two CC systems. One has separate CC controller and actuator, while the other is one box in the engine bay.

There is a diagnostic pin in the dlc too on some models.
Hope this helps a bit, although it is not a solutuion.

 

[turbodudey2]

The brakes and cruise control circuits are connected. The blinkers and cruise control circuits are not.

This is not completely accurate. The turn signals can and do back feed voltage into the stop lamp circuit when high resistance bulbs like LEDs are added.

And the stop lamp circuit directly affects the cruise control.

 

[pavelvoivoda]

This is not completely accurate. The turn signals can and do back feed voltage into the stop lamp circuit when high resistance bulbs like LEDs are added.

:

I just checked the diagrams, to confirm that the stop light and cruise control circuits are in fact interconnected (which is logical),but the turn signal and CC circuits however are not. Can you elaborate on what you are saying?

Assuming that the wiring circuits are not modified or have anything wrong with them, how would the turn signal circuit back-feed (not induce) into an adjacent circuit, when changing bulbs with higher resistance LEDs?

Thanks turbodudey2

 

[4RUNNING2THELAKE]

I am sorry for intruding into the "3rd Generation" section of the Forum. I have never used this forum to ask a question, only for educational purposes.
I have gone through the entire system, to the best of my ability, and still am unable to find any malfunctions. on the 2nd Gen Runners, somehow the t/s system does tie into the c/c system. Hence the LED light bulb issue I corrected by reinstalling factory style bulbs. The third brake light interrupter is the only thing that has changed. I am going remove that and see what happens.
I ended up taking my Tundra on the trip because of my heavy foot issue. Cruise is the only way to control my need for speed addiction. THANK you to all who responded with words of advice!!!!!!!

 

[KCtheGreat]

Okay, I'm experiencing a weird situation with my 4Runner. Whenever I'm driving at a higher rate of speed and I hit my right blinker, the RPM's jump slightly and kicks the cruise control off. If I hit my left blinker with the cruise on, my RPM's twitch but it stays on. With the cruise control turned off, the RPM's jump slightly with a left or right blinker. I originally thought it was a short with the headlight/blinker stalk because the stalk had broken off and was hanging by the wires. However, I replaced it a few days ago and still have the same problem. Any thoughts?

Did you ever fix the issue. I am experiencing the exact same problem. I've owned my 4runner 17 years never a problem Recently replaced the taillight assemblies with aftermarket LED tail light assemblies. Now I am having the cruise control turn off when the right or left turn signal is activated and the engine RPMs increase slightly when the turn signal is on at freeway speeds.

Does the problem maybe have to due with difference in resistance in regular bulbs and LED and possible resister needed in line. I haven't begun to try and fix mine yet

 

[jsukey]

Did you ever fix the issue. I am experiencing the exact same problem. I've owned my 4runner 17 years never a problem Recently replaced the taillight assemblies with aftermarket LED tail light assemblies. Now I am having the cruise control turn off when the right or left turn signal is activated and the engine RPMs increase slightly when the turn signal is on at freeway speeds.

Does the problem maybe have to due with difference in resistance in regular bulbs and LED and possible resister needed in line. I haven't begun to try and fix mine yet

I actually found another issue after changing out my rear LED lights. One of the screws that secure the plastic molding around the bottom of the rear hatch had been reinserted at some point, straight through a wire loom. Whenever I turned on my blinker, the screw was conducting electricity to the brake light wire. That’s why my cruise was cutting out. Others have mentioned that certain LED bulbs were the culprit. I ended up changing those out for stock tail lights before I found the culprit.

 

[spartacus]

Did you ever fix the issue. I am experiencing the exact same problem. I've owned my 4runner 17 years never a problem Recently replaced the taillight assemblies with aftermarket LED tail light assemblies. Now I am having the cruise control turn off when the right or left turn signal is activated and the engine RPMs increase slightly when the turn signal is on at freeway speeds.

Does the problem maybe have to due with difference in resistance in regular bulbs and LED and possible resister needed in line. I haven't begun to try and fix mine yet

This might help
Multi-Function Switch Malfunction?? Blinker & RPM's

 

[jross20]

Have you ever had issues with your door lock buttons (not the fob) not working, the dome light not working (without being blown), or with the cluster getting stuck?