Cruise control dies when turn signal used

[94landcruiser]

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 have in common.

Any ideas where I should start my search of the electrical system?

Gracias.

 

[CJF]

The cruise control has a diagnostic mode in which trouble codes are displayed by the cruise light (similar to CEL codes). It's pretty cool and surprisingly effective at pinpointing problems. Should be near the start of the cruise control section (in the body electrical chapter) in your FSM.

Keep us posted; I like seeing these issues get tracked down and hearing what the problem was.

Curtis

 

[gray]

I had similar issues (started a thread a couple of days ago) but more symptoms than described above;
https://forum.ih8mud.com/80-series-tech/198650-left-turn-signal-goes-brake-application.html

Does the OP's symptoms include the turn signal indicator light coming on when you depress the brake pedal? Do you hear a loud clicking if in Park when the turn signal (either) is flipped on? Foot on or off the brake pedal?

My symptoms stopped as quickly as they started.

 

[grunt001]

Just checking...but do you have LED tail lights? If so, the cruise control issue seems to come up for those with aftermarket LED tail lights.

 

[woody]

LED taillights AND a trailer brake harness/adapter....

I pulled that wire adapter that converts your wires to "normal" trailer wiring, and that cured my turn signal/cruise issue, even with the LED's installed.

 

[landtank]

remove the trailer harness module.

 

[94landcruiser]

No diag codes, no leds, no break light directional on, happens with left/right/hazards no recent changes to the trailer light system (installed an afttermarket trailer light connector just under two years ago) I will remove it to verify that is or is not the issue.

Thanks

 

[Squash]

Currently addressing a remote start problem. The remote is seeing a brake application so it fails, but if I step on the brakes the stupid thing will fire up.

Started with the easiest: Clean up ice and corroision in trailer harness which has been left outside and tucked into bumper, now put inside and out of the elements

Cut off trailer harness
Disconnected brake lights
Pulled fuses

Next I will pull and change bulbs then if the trend continues shoot myself...

Good luck

 

[CJF]

No diag codes

There are a *lot* of diagnostics for the CC; you're sure you read/tried them all?

For example:

1) When the CC cuts out on you, the light should flash a few times. This tells you there is a code that can be retreived (using the diagnostic port under the hood), but I'm pretty sure you have to pull it before shutting off the engine.

2) You did the full diagnostics mode where you test each circuit from the driver's seat, and the light flashes various responses at you as you perform each test?

Curtis

 

[94landcruiser]

I am driving, I use the directional. Cruise stops, CRUISE stays lit, no flashing, complete lane change CC resumes as if I hit the brake.

I ran numerous tests from the FSM all passed.

 

[94landcruiser]

As an update WD40 sprayed on the actuator's spring area solved this as well as the sporadic cc dying & light flashing I had.

 

[Dork]

So, I'm bringing up a long dead thread, but maybe someone has an answer by now.

This summer I noticed that my cruise control was on the fritz exactly as described above: cruise turns off when the turn signal is used. Very annoying on dual lane highway. At the same time, my remote starter (some aftermarket Viper unit that was installed on the vehicle in Japan) stopped working. It would go through it's indicator blinking routine, but instead of hitting the starter, it would just lock the doors again and go back to waiting mode.

I pulled the trailer wiring adapter out, and suddenly it's all working. I'm guessing that the part of the adapter that takes the brake signals and turn signals and puts them to the same lamps is confusing the cruise brain and the remote starter mind. This adapter is just a cheapo thing that came from Princess Auto (Canadian Harbour Freight)

Does anyone know of a trailer adapter that plays nicely with the cruise, etc?

 

[Michael Hanson]

Hi, I've found no problem with U-Haul adapters . But read the directions on grounding them , they have a specific way to ground .They all wear out after years of service , esp. if mounted in the weather. Mike

 

[LandCruiserPhil]

Trailer wiring has been the problem source for a ton of electrical problems....

CC testing

A. Turn the ignition switch on.
B. Turn the control switch to S ET/Coast position, and keep it there.
C.Push the main switch ON.
D.check that the indicator lig ht "CRUISE" lights-up in the
combination meter.
E.Turn the SET/Coas t switch off
F.Meet the conditions listed in th e table below.
G. Read the diagnostic code on the cruise contr ol indicator light.
.................................................. ................
#1 Turn the control switch to SET/Coast position
there should be two flashes and then a second br eak and then two
flashes, then break then two flashes etc. If you get the flashes your
SET/Coast circuit is normal.
#2 Turn the control switch t o RES/ACC possition.
this time you get a pause and three flashes, repe ated again and
again. if you get the three flashes RES/ACC circuit is ok.
#3 Each switch is turned on
a. Control switch to CANCEL .
b. Stop light switch, (step on brake)
c. parking brake switch. ( pull up par king brake)
d.Neutral start switch. ( put in neutral)
if when you test each of the 4 cancel sw itches you DO NOT get any
flashes then those switchs are normal.
THIS IS YOU, And now you have to lea ve the driveway.
#4 Two parts for speed sensor
A. Drive at 25mph or below. if t here are NO flashes sensor is normal.
b. Drive at 25mph or over. you should get constant steady blinking.
if she blinks sensor is ok.

 

[baggar11]

I had this issue years ago after getting my alternator rebuilt. One day, I popped the hood and noticed one of the alternator connectors(I think ground) was pretty black. I cleaned it up and made sure it was making a good connection. Took take care of the cruise control/blinker issue in my case.

 

[MotoGuzzolene]

Late to the party. Sudden oddity for me as well - ONLY RIGHT SIGNAL. NO trailer harness. No changes since last I used cruise normally. Will let y'all know what I find.

 

[94landcruiser]

WOW! I had no idea this was alive, glad it may have helped others, sadly I had to sell my 80 in late 2009 to try & save my dog (8k in vet bills suck, not saving her was worse)

I miss the 80 about as much as the dog. but my Magnuson SC Sequoia helps!

 

[FIDO96]

Late to the party. Sudden oddity for me as well - ONLY RIGHT SIGNAL. NO trailer harness. No changes since last I used cruise normally. Will let y'all know what I find.

Welcome to 2025. Took my 97 FZJ80 from
Dallas to Houston this weekend. Everything worked great except when running on CC, a right turn signal would deactivate cruise.

Facts:
1. I have LED bulbs and aware this is a potential issue
2. Only happens when activating the RIGHT signal. The left signal does not shut-off the CC
3. I have an old four-wire trailer harness tucked under the rear bumper. I will never tow with this vehicle.
4. Brake lights, turn signals, hazards all work as expected, except much brighter and efficient than old-school filament bulbs.
5. No flashing or odd CRUISE lights. Just turns on when I press the end of stalk and stays on until I manually press again or shut-off engine. Works as expected.

So, any chance the Right turn indicator impacting the CC can be eliminated like the left side? Trailer wiring deletion?