1975 Ford Bronco Turn Signal Mechanism Test?

[MerganserMaster]

For some reason the "blinkers" do not work in my Bronco. I have confirmed that the light bulbs in them are good and the front blinkers (on the grill between the headlights) will "blink" when the hazards are pulled. However regardless of the position of the turn signal "lever" no blinking occurs either on the gauge cluster on any of the lights. Attached are pictures of the blinker "mechanism" and the gauge cluster (when the lights knob is pulled). How can I go about testing the blinker mechanism so that I can see if there is even power coming to it (or going away from it)? Is it possible for the metal to be worn out or something that would cause a signal to to transmit? If so, is there a way to fix it (at least temporarily) tinfoil or other conductive material? Thanks. (I have checked the turn signal fuse and also the brake lights and headlights work just fine if that is related to anything).

https://flic.kr/p/2pUpQnh
https://flic.kr/p/2pUwcke
(Also, anyone know what the red light up top in the middle means?)

 

[ared77]

I don't have a schematic here in front of me but I'd guess because the flashers work that might be a good clue. When you say you checked the fuse did you measure for 12 volts on both sides of it?

 

[Brush Hog]

Check for a bad flasher. Under the dash that makes turn signals and hazards “flash” on and off.

 

[MerganserMaster]

Check for a bad flasher. Under the dash that makes turn signals and hazards “flash” on and off.

any good way to "test" it? Or should i just buy a new one from the parts store?

 

[MerganserMaster]

I don't have a schematic here in front of me but I'd guess because the flashers work that might be a good clue. When you say you checked the fuse did you measure for 12 volts on both sides of it?

I did not, but I will be sure to

 

[Speedrdr]

Is it possibly (?) your dimmer switch or brake switch grounding and causing this problem? Can’t say for certain, but it’s a location to check.

Randy

 

[Brush Hog]

any good way to "test" it? Or should i just buy a new one from the parts store?

Not sure how to test. Maybe swap it with the hazard flasher since you know it works and see what happens. Are you using LED bulbs or standard bulbs? LEDs can be finicky.

 

[Oldtimer]

Red light in center of cluster means High beams are on.
Two green indicators in cluster should NOT be illuminated when head light switch is pulled, only when front turn signals are activated.
IF front turn signal buckets don't have a good ground, turning on headlights will cause 12v to back feed thru front turn/park bulb fillaments, and illuminate indicator bulbs in cluster.

Here is link to SeaBiscuit68's Bronco schematics: https://seabiscuit68.tripod.com/

 

[MerganserMaster]

Sounds like I should double check all of my grounds. Also I got some more fuses and the second I place one in the panel (in the turn signals/ B/U lamp / Windshield washer pump (which has been removed) slot) it instantly blows (despite being 14 amps) the second I turn the key to the acc position. I am assuming its shorting out somewhere but even after looking over the wires (and disconnecting the turn signal mechanism from the wiring) I cannot seem to find anything wrong with it. Any good places I should check ?

 

[DirtDonk]

Has the bronco been completely rewired? If so, what harness is in it?
Is this Bronco new to you, or have you had it awhile?
Did the problems just start, or have they been going on for a while?

Was the picture taken with the headlight switch fully on? If so, try flipping the dimmer switch to see if your highbeams are on. If so, then clicking the switch to low positions should make the red light go out.
If it doesn’t, there are definitely some issues going on.
The two green turn signal indicators should only be tied into the, bright filaments of the front turn signal bulbs.
Did you happen to change the front turn signal buckets at any time?

 

[MerganserMaster]

Has the bronco been completely rewired? If so, what harness is in it?
Is this Bronco new to you, or have you had it awhile?
Did the problems just start, or have they been going on for a while?

Was the picture taken with the headlight switch fully on? If so, try flipping the dimmer switch to see if your highbeams are on. If so, then clicking the switch to low positions should make the red light go out.
If it doesn’t, there are definitely some issues going on.
The two green turn signal indicators should only be tied into the, bright filaments of the front turn signal bulbs.
Did you happen to change the front turn signal buckets at any time?

To answer your question: It appears the Bronco was rewired at one time, probably by a previous owner (unless the wiring harness came wrapped in plastic electrical tape from the factory). Also I found where the short was. It appears that the under dash light wire was grounded out as for some reason it was set up that way. I have fixed it now and the turn signals, hazards, and brake lights all work fine now. The vehicle passed inspection in SC in 1995 or so so all legal/necessary lights were set up to work but the two signal indicators still light up on the dash when the headlights switch is pulled. I will eventually fix it but as it doesn't cause any problems Ill push it to the side for now. Big thanks for all of your help.

 

[DirtDonk]

A couple of easy checks. First, make sure that when you pull the headlight switch on, it is the running light filaments in the bulbs that are lit up. Not the turn signal filaments.
Since the front signals are where the indicator lamps get their power, if those are backwards, then the lights could light up.
Do you by any chance have new front turn signal buckets?
The aftermarket ones are often wired backwards and need to be fixed before installation.
So when you turn on your headlights next time, make sure that your front running lights are not super bright.

 

[MerganserMaster]

A couple of easy checks. First, make sure that when you pull the headlight switch on, it is the running light filaments in the bulbs that are lit up. Not the turn signal filaments.
Since the front signals are where the indicator lamps get their power, if those are backwards, then the lights could light up.
Do you by any chance have new front turn signal buckets?
The aftermarket ones are often wired backwards and need to be fixed before installation.
So when you turn on your headlights next time, make sure that your front running lights are not super bright.

Ill check this, never thought of it before, but this could be the case. The lens are marked FoMoCo (or whatever the Ford logo they put on there is called) but it never hurts to try Especially since the previous owner wired a lot of goofy stuff on it.

 

[DirtDonk]

If it says "FoMoCo" on it, it's probably original. I think Dennis Carpenter can use that logo on some stuff (maybe?) but I have not noticed it being on the replacement light buckets.
I think we still have to check every one that comes through our loading dock to be sure it's either working properly, or to fix it before it goes out to a customer. And even then, every once in awhile one gets past and ends up causing grief out in the world. Although, maybe instead of missing one, we actually "fixed" one that didn't need it!
That would be one in a hundred probably. They all seem to be wired backwards.

Still, hoping for something simple like that in your case.

Paul

 

[MerganserMaster]

If it says "FoMoCo" on it, it's probably original. I think Dennis Carpenter can use that logo on some stuff (maybe?) but I have not noticed it being on the replacement light buckets.
I think we still have to check every one that comes through our loading dock to be sure it's either working properly, or to fix it before it goes out to a customer. And even then, every once in awhile one gets past and ends up causing grief out in the world. Although, maybe instead of missing one, we actually "fixed" one that didn't need it!
That would be one in a hundred probably. They all seem to be wired backwards.

Still, hoping for something simple like that in your case.

Paul

Ok, now there must be something weird going on with the wiring. The drivers side indicator bulb is now off (like it should be) but the passenger side one is still on. Both sides still "blink" but if the hazards are pulled they blink at slightly different intervals. I went for about a 2 mile trail ride (very bumpy, but slow) so maybe that did something