FJ40 Turn Signal Trouble shooting

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rorkis

rorkis

REO1
10 Year 15 Year
Joined
Jul 18, 2007
Threads
12
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175
Location
Columbus Ohio
Have 77 FJ40. Hazards work fine but the turn signals just stopped working. All other lights work fine including brake lights. Checked all fuses. Checked flasher unit and can not see anything wrong and since the hazards work I think the flasher circuit is fine. Any ideas on what it could be? Only thing left that I can think of is the actual turn signal switch on the steering column. Any other ideas?

Thanks in advance for the help
Randy:beer:
 
Thanks. It actually only has one 2 terminal flasher that works both the hazard and turn signal circuits. I had a 69 that had seperate flashers like yours. Much simpler...wish that was what is in mine.
 
Thanks already read that article. Interesting it does not really say anything about the grounding problems. Does anyone know where the key ground points are on a 77 FJ40? All lights work fine. Just no turn signals.
 
Had the same problem on my 76 and it was corrosion at the connections on the back of the hazard switch. The turn signal circuit routes through the hazard switch. I just pulled the hazard switch cleaned it and put it back. No problems since.
 
Quick grounding tips:

1. Most lighting ground problems are in the light housings. Toyota relies on the housing to ground itself to the body/frame. Rust will eventually cause the ground to be lost or become intermittent. The lamp sockets (where the bulb goes) also get corroded. The solution is a Dremel tool with a wire brush mounted to clean the sockets and housing to body/frame contact point.

2. The wiring system on an FJ40 has a few grounding points that need to be addressed.

A. The main ground for the system is of course the battery negative cable to chassis. There should be TWO grounds: One from the battery to the frame rail, then from that point a short jumper cable to the starter mounting bolt on the engine block. This provides the frame and engine block with good solid grounds. Note that the engine is mounted to the frame with rubber isolators so the engine may not be grounded well through its mounting bolts, IE the reason for the jumper. Engine ground is really important for the starter AND the alternator to function properly. Also idle solenoid, temp sensor, and the oil sensor.

B. Next are the wiring harness grounds. The primary harness ground on older trucks is located at the external regulator. There is a WB wire that comes from the harness and attaches to the regulator E terminal. The E terminal is directly connected to the regulator case therefore the regulator case MUST be well grounded to the body! This ground is critical! It is the ground wire for the alternator, headlights, VSV, heater blower and wiper motor!

The rear chassis harness ground is located under the truck on the passenger side frame rail about where the t-case is. There is a brass ring terminal with two WB wires going to it that is bolted to the frame. This ground is only for the t-case 4WD light and the fuel gage ground.

Everything else on the FJ40 grounds to the body or chassis through its mounting bolts.

So when someone say to check the grounds now you know what to check. ;)
 
Thanks that is great info. One question. If all other lights work fine could it still be a ground at the light housings? Emergency flashers, tail lights, brake lights, head lights, side markers...etc all work. Only the turn signals do not work.

THanks..Randy
 
rorkis, you didn't say, but based upon your detailed checks, I'm guessing that you did also check the bulbs, correct?
 
rorkis said:
One question. If all other lights work fine could it still be a ground at the light housings? Emergency flashers, tail lights, brake lights, head lights, side markers...etc all work. Only the turn signals do not work.
Click to expand...

Yes it could still be the ground. I had an issue with my rear lights, I don't recall if it was the turn signal, running or brake function - but one of them was not working until I cleaned up the housing to frame mating surface. :)
 
When you say "checked the fuse", what exactly does that mean? Make sure there is no corrosion on the fuse block terminals. 12 volts is very little EMF, and it takes only a slight amount of corrosion to break a circuit... U need bright shiny brass connections in the fuse block, a good fuse, then check for power going to the switch...
 
Thanks to everyone. I have checked the bulbs....all work fine. All other lights work fine.....Hazards flash, brake lights, parking lights...etc. The only thing that does not work is the turn signals when I try to operate them from the turn signal switch on the steering Column. Based on all of your comments I believe it has to be in one of the following.

1. The actually turn signal switch
2. Ground somewhere in the flasher circuit but doubtful it is in any of the light housings since they all work and it is only the turn signals from the turn signal switch that do not.
3. Could be the hazard switch or somewhere else in the energized side of the flasher circuit. Hazards work and that is the part that is not tied to the ignition switch. Only when tried from the turn signal switch do they not work. Checked the fuse and fuse block. Have had that problem before....so I am confident it is OK inless there is short or break in the wire connectors on the back side of the fuse block.

Anything else someone can think that I could be missing?

Anyone have a good source for a new turn signal switch for the steering column. I is a 77 with a production date of Nov 76.

Thanks...Randy
 
similar issue

I too have an 11/76 "77" FJ40...and had similar goofyness going on with the blinkers. I checked and ran new grounds, all new bulbs, relay. I could hear the thing click once...but no flashing. then I realized, I neglected to check the power connection. after cleaning them all up including the 'bullet' type connectors on the fender well (maybe a po addition?), been working since. obviously that was simple on my rig, and hopefully something simple like that, too.
 
I would think if it were a ground, it would only affect the one side/corner the ground was bad. My '77 had a bad ground (among other problems), but the bad bulb (ground) only appeared at the corner of the corrosion/bad connection.

If both sides...front and back aren't working...I would go after the switch, and connections with that.
 
On a 77 ALL park lights are fused by the Tail light fuse. The headlight switch is what turns them on and off. If NONE of you park/taillights are working AND the fuse is good then it's probably the switch or something has come unplugged.

You need a meter to verify operation. If you can find a friend with a meter that knows how to use it they can download the 77 schematics from here: Coolerman's Electrical Schematics and FSM File Retrieval scroll down to the FJ40 section then the 77 section. Click on each file to download.

Good luck!
 
1sttime40 said:
Had the same problem on my 76 and it was corrosion at the connections on the back of the hazard switch. The turn signal circuit routes through the hazard switch. I just pulled the hazard switch cleaned it and put it back. No problems since.
Click to expand...
X2,
The hazard switch control both hazard circit and signal circit.
Often it needs to be taken apart and have the contacts cleaned.
IT will be impossible to have a bad ground here.
The hazard switch is not easy to get to so to confirm that it is the problem , here what you can do.
Unplug the flasher and push the Haz knob all the way in and turn ig key to the on position.
If you have no power going both sides of the flasher plug , it is very likely with the Haz switch (power feed side) or in the connections to it.
You already know the connections are good to the bulbs , because they work with haz which shares the same circit up to the Haz switch.
If you have power going to the flasher then , it is either your signal switch or the connection between the signal switch and haz switch which means the connectors and the contacts in side the haz switch( the haz is failing to connect the bulbs back to to the signal switch output wire .
I am assuming that all signals flash when you pull the haz and when you work the signal switch nothing happens.
 
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