Cruise cancels when turn signal actuvated (1 Viewer)

[LLTB]

Hi everyone - I bought this sweet 80 from Erich and am working on fixing a few things on it. I had a nice 2000+ mile drive home with my son from Virginia to Utah to get to know the truck. She drove nice and smooth all the way. Erich did a great job building it up. That being said, there are some small things I noticed that need attention.

One thing that is absolutely driving me crazy is that when I set the cruise control, it will instantly cancel if a turn signal is activated; using the turn signal stalk or the hazards button will cancel the cruise.

I know from having worked on my other Toyotas that the clock spring reel under the steering wheel and also the switch on the column are two common things that can cause cruise control to fail to work at all.

But in this case, cruise will activate and hold no problem. It just deactivates when turns are activated.

Sounds like maybe a shorted ground wire to me.

Anyone ever deal with this issue? Thought I’d ask before I start ripping the thing apart.

 

[Dusten]

On Ford's this was a burnt out bulb. Especially third brake light.

 

[LLTB]

L

On Ford's this was a burnt out bulb. Especially third brake light.

no bulbs out that I can see except some in the instrument cluster on the dash… but ill double check

 

[Dusten]

Lots of threads on this

Cruise control dies when turn signal used

Last week I was driving with the cruise control on and when I changed lanes the cc turned off. I put it back on, all well then it happened again. It took a few more times before I connected that the turn signal was causing it. I searched the electrical FSM and see nowhere these systems...

forum.ih8mud.com

 

[smritte]

If you have LED tail/stop lights, LEDs backfeed. Its possible you have just enough voltage going back to the stoplight circuit to make the cruise think your stopping.
This has been a problem across most car lines.

 

[LLTB]

If you have LED tail/stop lights, LEDs backfeed. Its possible you have just enough voltage going back to the stoplight circuit to make the cruise think your stopping.
This has been a problem across most car lines.

Not sure if the turn signals are LED but I’ll check that - thanks!

 

[jonheld]

Not sure if the turn signals are LED but I’ll check that - thanks!

Not the turn signal bulbs.
The brake lamp bulbs. If these are LED, the turn signals will cancel cruise control.

 

[Kernal]

One of my 80's had an issue where cruise would shut off when the headlights were turned on, started as soon as I replaced an original burned out brake bulb with a (new) standard filament style Sylvania brake position bulb. No problem with cruise control if I left the defective bulb out of the tail lamp but it came back as soon as I individually tried two new bulbs out of the same package. Bulb socket had zero corrosion but cleaned it as well as the harness connector then reinserted the new Sylvania bulbs (2) but no improvement with either so replaced with another new bulb (different brand IIRC), no issues after that.

IIRC the new bulbs were defective, glowed slightly when the brake pedal wasn't depressed.

 

[LLTB]

Not the turn signal bulbs.
The brake lamp bulbs. If these are LED, the turn signals will cancel cruise control.

The brake lights ARE LED.

 

[Dusten]

The brake lights ARE LED.

So replace them

 

[surfpig]

The brake lights ARE LED.

That's the problem. BTDT

 

[Francis K]

Getting rid of my led tail light's fixed every weird electrical issue I had including that same cruise control issue.

 

[Filo Bedo]

Do you have a trailer plug wired in? Mine started doing the same thing when I installed a trailer plug wiring harness.

 

[LLTB]

Just wanted to cross link to this other thread here - this $8 fix totally worked for me - I can keep my DEPO rear taillight housings with LED brake lights and now my cruise doesn't cancel when I activate my hazards or turn signals.

I liked the idea of JB welding the resistors to the body panel to dissipate heat, so I did that inside rear quarter panels. I also have upgraded the backup lights to bright LED bulbs, so I put resistors on the backup lights as well, 4 resistors in all.

This 4-pack of resistors are what I ordered from Amazon.

 

[Saito]

Just wanted to cross link to this other thread here - this $8 fix totally worked for me - I can keep my DEPO rear taillight housings with LED brake lights and now my cruise doesn't cancel when I activate my hazards or turn signals.

I liked the idea of JB welding the resistors to the body panel to dissipate heat, so I did that inside rear quarter panels. I also have upgraded the backup lights to bright LED bulbs, so I put resistors on the backup lights as well, 4 resistors in all.

This 4-pack of resistors are what I ordered from Amazon.

Projector LEDs are the hot ticket for back up bulbs.

 

[thedoughboy]

One thing to note, @LLTB, I did NOT attach the resistors to the body panel. The resistors get hot, real hot, and melted a hole in the tail light housing. I have since replaced the housing, removed the resistors, and just deal with the cruise control when it cancels.

 

[jonheld]

Just wanted to cross link to this other thread here - this $8 fix totally worked for me - I can keep my DEPO rear taillight housings with LED brake lights and now my cruise doesn't cancel when I activate my hazards or turn signals.

I liked the idea of JB welding the resistors to the body panel to dissipate heat, so I did that inside rear quarter panels. I also have upgraded the backup lights to bright LED bulbs, so I put resistors on the backup lights as well, 4 resistors in all.

This 4-pack of resistors are what I ordered from Amazon.

If you're adding resistors to increase the load, then why even bother with LEDs in the first place?

 

[LLTB]

I bought the 80 with the LED lights already on it. I don't have any original tail lights. I'm just trying to get everything on it working.

 

[LLTB]

Projector LEDs are the hot ticket for back up bulbs.

That is what mine has. They're pretty great!