Turn signal flasher
 

Hi everybody,

I think I have a little problem with my flasher. No turn signal, no clicking noise.
At the moment there is a Tridon LF12 on the fuse panel with 2 pins. I want to buy a new one, for example the BUSSMANN NO552 Thermal with 2 terminals. Maybe someone please can tell me if it fits?

On the Tridon I read "input lead (X) must be fused". On my fuse panel the terminal "L" (brown wire) is fused if I'm right. Is that correct or is there another/further fuse necessary?

https://up.picr.de/45083016kd.png

https://up.picr.de/45083028hp.png

Would be great if someone could help me :)

Re: Turn signal flasher
 

Any 552 should fit. If by "fit" you mean physically, just use the dimensions given on the drawing for blade spacing and other physical sizes. 552 is the correct series of flasher.

If your wiring is still original, all is protected by the fuse panel. You are good to go.
X= 12V battery input
L= load (the bulbs basically)

This is just answering your question, not stating that the flasher is your problem. You will find out. Let us know.

Re: Turn signal flasher
 

AZKen, thank you a lot for your reply.
Yesterday I tested the flasher directly on the battery with a bulb on L and I hear it clicking and see the bulb flashing :D
Now another question: on the both contacts of the connector for the turn signal (blue marked) should be a flashing 12V voltage on my multimeter. Is that correct? The harness is completely new wired according to the original circuit diagram.

https://up.picr.de/45087467ff.png

Re: Turn signal flasher
 

You would not have an alternating (0-12-0)reading on your mutli-tester anywhere pass your 2 or 3 prong flasher unless the circuit is connected to a load (light bulbs) - the flasher needs to be loaded to break circuit flowing. The turn signal switch in your steering wheel hub only directs the voltage signal to where you want it. When I did trouble shooting I would establish power to the circuit (input on flasher) - then make sure there is a load to complete the circuit on the other end (light bulbs or ect). I would look at your turn signal switch for the problem - do you have brake lights?

Re: Turn signal flasher
 

Please reset and describe what problem you have so we can begin proper trouble shoot and ask questions.
To check for flash anywhere, use an ice pick volt testing light. That way even though you have a connector unplugged, the test light will flash. You can test all the way to the bulb contact. Alligator clip on ground and ice pick on point to be tested.

But first describe what is wrong with what. You are asking good questions but you are too far ahead of us. First we want to know what happens when all is hooked up and turn signal lever is on left and right.

Re: Turn signal flasher
 

Great support :signthankspin:

First I will test the voltage directly on the panel fuse if there is voltage for the flasher but I'm with you. Main problem was that the turn signal harness was not connected. I will work through your points and questions. Would the turn signal lever work without the tail light for a first test? The rear lights are not connected at the moment.

I'm a total beginner but slowly learning a bit more about the car electronics and thank you for the advice with the ice pick volt testing light.

Further question: on my truck the pre owner used the following sockets for the turn signals. Think they are for the taillights and they don't really fit in the opening of the metal housing. Are there "original" ones available?

https://up.picr.de/45092809ht.jpg

https://up.picr.de/45092825yv.jpg

Re: Turn signal flasher
 

Ok, I connected the front harness with the turn signal and the rear harness with tail lights. Originally wired.

I have no turn signal and no brake light. Only the tail light is working. Flasher is also working directly connected to the battery.

On the brown connector on the fuse panel where the flasher is placed, my multimeter shows 12V (with ignition on). But now I found out that on the brown connector is connected the L of the flasher.
For my understanding L is normaly load with bulbs and ground. Should I change brown and violett connector on the fuse panel? X = battery/brown, L = bulbs/ground/violett. Please correct me if I‘m wrong.



Greetings

Re: Turn signal flasher
 

Brake lights/turn signals are the same circuit (wire) - tail lights are different wire (circuit). See if you have power (12 volts) at your turn signal switch and your brake light switch - they let us know. Please don't change any wires around UNLESS you changed them yourself earlier. Again - let us know if you have power to BOTH switches - THANKS!:winter:

Re: Turn signal flasher
 

On the brake light switch I have 12 volts. When I push the brake pedal I also have 12 volts on the other wire.
Sorry for asking but what is the best way to test correctly the turn signal switch?

Re: Turn signal flasher
 

On the steering column near the bottom where your brake light switch is connected to your swing pedal support you should see a 2 piece curved wiring terminal with numerous wires that plugs together - pull it apart and take your multi-tester set on ohms and once you studied the wiring systemic of the turn signal switch and know what colored wires are L and R turn signal wires - connect 1 probe of tester on input power wire and the other on the output wire on what your have moved your lever to - if your meter shows the contacts are closing and complete your chosen circuit - if good you know so far that your brake circuit works and your turn signal switch is functioning -------- next move would be checking your wires that run along your frame rail - remember brake and turn signal share the same wire and since you have neither - leads to me to think you have problems with the rear wiring harness. Let us know what you find. THANKS!:thumbsup:

Re: Turn signal flasher
 

Tested the turn signal switch with the right colors together. No reaction on the multitester with ohms. Multitester current directly through the cables of the turn light switch is ok.

Stop light switch shows me some resistance.

Thanks for your patience :winter:

Re: Turn signal flasher
 

Update
Everything is hooked up.
- Front light is OK
- High beam is OK
- Parking light (separate harness because of law here) is OK
- Tail light is OK
- Dome light is OK

- Turn signal front not OK
- Turn signal back not OK
- Brake light not OK

Tested the wires:

- Orange wire brake switch 12V
- White wire brake switch 12V if pedal is pushed
- White wire on the connector to the turn signal switch 12V if pedal is pushed
- White wire on the connector of the turn signal switch 12V if pedal is pushed
- Green wire on the turn signal switch 12V if pedal is pushed and switch in neutral position
- Other wires no voltage in neutral or left/right position

Maybe someone have an advice

Re: Turn signal flasher
 

Hello Tom, I recommend starting new on this wiring thing. OK? Here we go.

Stop testing. Stop looking at fuse panel. For now.
Look at the wiring diagram for 1965 GMC. You will see the turn signal switch. The diagram shows Violet. N(white), Black, Dark Blue, Light Blue, Dark Green, Yellow and Gray wires. 8 wires coming out of the switch. (One extra gray wire probably not there).
Find the connector from thr swich wher Lizzy describes..... and tell us if there are those wires and those colors coming out of the turn signal switch and going to one half of the connector. Do not proceed until you post this information. Make sure you check this website forum often so the time zone difference does not slow us down too much.

We should now go one step at a time at first.
As you know:
The "Turn Signal Switch" is a switch inside the steering wheel/column. Operated by a lever.
This switch has wires running down the column to one half of a connector.
The other half of the connector is wired to the truck/harness.
These connectors are "plugged" into each other (mated).

If any test are given, we will only be interested in finding 12V, not ohms. Unless we want a continuity test, which just confirms if a wire is connected from one point to another. We won't need an ohms value. You will find the Continuity setting on your multimeter. Sometimes it's a buzzer sound.

You need to have a front dual filament parking brake socket/bulb each side. In the rear you need the rear light to have a dual filament socket/bulb each side. Please advise. Also Please explain fully and completely so we can understand this statement "Parking light (separate harness because of law here)"

I see you are doing a wonderful restoration. Good job. I believe your lighting problem is just a slight miswire which we will find as we proceed slowly.

1. Did you buy a complete harness or building your own? If you bought one please give vendor and part number of the harness.
2. If you are making your own, what fuse panel, what sockets, what connectors are you using? Vendor and part number. Explain carefully.
3. Are you using original headlight switch, park and tail sockets, ignition switch, turn signal switch????
4. What is your experience level with automotive wiring?

It's always a bit more difficult for both of us due to slight language and time zones. We try not to wait days for each response if we can. We will lose progress. I will do my best.

Re: Turn signal flasher
 

Try to do my best :)

Please see the picture. On the turn signal switch (right side of the picture) I have the following colors:
violet, white, black, yellow, dark blue, light blue, dark green. I cut away the half moon connector because on truckside harness it was missing. I crimped a new connector. On the side of the turn signal switch I removed the connector for the photo to get it out of the steering column.

https://up.picr.de/45223789zu.jpg

I took the steering wheel apart to test the switch. The half connector was missing on the old harness, so I crimped a new one. Unfortunately I was not able to get a new half moon connector. Seems that they are no longer produced/available as a spare part.

https://up.picr.de/45223838gk.jpg

https://up.picr.de/45223839yx.jpg

OK, I understand.

On the front firewall harness I have the violet wire that is an own circuit (not connected to the turn signal bulbs). Small lamps for the violet parking brake circuit are included in the head lights. The violet wire leads from the firewall connector to the small lamp socket in the headlight and from the socket I have a black wire to ground. Parking light funciton is perfect.

https://up.picr.de/45223815zb.png

https://up.picr.de/45223817qd.jpg

https://up.picr.de/45223819hm.jpg

https://up.picr.de/45223822ws.jpg

https://up.picr.de/45223823ov.jpg

https://up.picr.de/45223824pv.jpg

https://up.picr.de/45223825bg.jpg


Thank you very much AZKen. The project still makes me proud :)

1. I build the harness on my own.
2. I used the original fuse panel, the original sockets, and bought new original connectors/terminals (Packard 56 Serie) or used the original ones which were in good condition. The only connector I was not able to buy was the half moon connector of the turn signal / truck side harness.
3. Head light switch I don't know if it is orignial but the wiring is like the original one. Tail sockets are new from LMC and park sockets are after market I think. They were put in by the pre owner. Ignition switch is original, also the turn signal switch.
4. No experience in automotive wiring until this project.

https://up.picr.de/45223827vg.jpg

https://up.picr.de/45223828eq.jpg


I appreciate your help. Thank you :)

Re: Turn signal flasher
 

Ok I am studying your message an pics. Stand by.

Re: Turn signal flasher
 

First question. Front lighting. Why did you use a headlight with built-in bulb instead of the park and turn lights on the hood? What is that little built-in bulb for? So you must be saying that your law requires that you use a sealed beam head light with the turn signal built into it and use a separate light (in your case the lights on the hood) as the park lights?

Re: Turn signal flasher
 

Park light in combination with turn signal in the hood is not allowed in Austria/Germany. We have to use this small bulbs in the headlight for our parklights. Only white light is allowed for parking light.
Turn signal for itself in orange in the hood is OK.
It is also not allowed to use sealed beam head lights. It must be possible to change the bulb (H4) in the event of a failure.

Re: Turn signal flasher
 

OK, so no need for dual filament up front, right?

next question. What are the square plastic orange colored items on the wires? Are they a splice? why?

Re: Turn signal flasher
 

With that connectors you can connect wires with one click. I only used them for testing the turn signal bulbs directly on the battery if the bulbs and flasher were ok.

Re: Turn signal flasher
 

So, they will come off soon? They seem to be the turn signal, right? and then how will you wire? direct to socket contact of the turn signal housing.?

Re: Turn signal flasher
 

Next
Everything is hooked up.
- Front light is OK.......
- High beam is OK............
- Parking light (separate harness because of law here) is OK ...........
- Tail light is OK.........
- Dome light is OK......
- Turn signal front not OK
- Turn signal back not OK
- Brake light not OK

So starting at top of your list.
Headlights work with headlight switch? H4 bulb?????
High beams work with dimmer switch?
Park lights work with headlight switch? T10 bulb?????
Tail lights come on with headlight switch?
Dome light is satisfactory.
DO YOU HAVE ANY LED BULBS? These may take a special flasher to work. May take a relay or two to work.


I will cover the "not" working after we get these answered. I will wait a few minutes and then go to bed.

Re: Turn signal flasher
 

When I install the turn signal wiring harness on the hood they will come off. It's only for testing to connect the wire of the socket with the wire of the harness. I will directly wire to the socket with a crimp connector.

Re: Turn signal flasher
 

Answered your questions in blue color.
Thank you for your service :thumbsup:

Re: Turn signal flasher
 

Re: Turn signal flasher
 

Ok now to the turn signals.
1. I see a pic with the front turn signal sockets laying on the drivers inner fender. Wired and ready for testing. Each socket has a dual filament bulb. Correct?

2. I see in same pic the rear tail light housings with sockets installed. Wired and ready for testing. Each housing has a dual filament bulb.. Correct?
I realize some of the test wires are temporary.

3. I see your pic of turn signal connections. I understand you have the truck side all done with packard 56 connector shell and contacts. You have just the contacts plugged in from the switch side for testing, No shell yet, Correct?
Do you have the colors matched at that connection? If not matched Please give color to color list. Switch side "in" color and truck side "out" color.

4. You have a wideside bed. Correct? Not "step side".

Re: Turn signal flasher
 

Answered your questions in blue color

Re: Turn signal flasher
 

OK, Lets check your wiring.
For the front turn signals. You have a dual filament bulb. That is OK but you will only use the large filament. I see three wires on each socket. This means only one socket wire will be wired to turn signal for each side. One wire not used and the ground will be attached to good ground place near light. Assuming the black wire is for ground. Socket may ground itself to hood when installed.
The left front T/S lamp large filament wire will be wired to Light blue switch wire. Right front T/S lamp large filament wire will be wired to dark blue switch wire. (Each of those will have a companion wire to the dash turn indicator bulb. Either two wires from one terminal or spliced. See diagram.)

If you test bulbs before installing on truck, the sockets/housing MUST BE GROUNDED.


Rear turn next:
You will use both filaments on each light. One is from the light switch only(small filament) and one from the T/S switch (large filament). Large filament left rear is wired to yellow switch wire. Large filament right rear is wired to dark green switch wire.
Small filaments are spliced together with license light, any way you wish....and they are wired to the headlight switch brown. So three wires going to rear. I usually eliminate the rear connector shown on diagram. This reduces voltage loss, intermittence and possible moisture entry.

This leaves VIO WHT BLK switch wires.
1. VIO is supplying the flash signal to T/S switch and is wired to fuse panel flasher terminal "L"
2. WHT goes to one terminal of brake switch
3. BLK goes to horn relay.
4. Other terminal on brake switch goes to headlight switch terminal as shown on diagram. Same terminal as a fused hot. see diagram.
Of course some wires mentioned may go thru connectors where indicated on diagram.

FIY: When making a turn and at the same time applying brakes, the turn signal switch shuts off the large brake light filament from brake switch power on that side, to allow the large filament to flash. That is why the brake switch is wired to T/S switch.

So now you have work to do. Please advise any questions or difficulties. Check fuses.. some could be blown by previous tests/activity.

Re: Turn signal flasher
 

Answered your questions in blue and red

Re: Turn signal flasher
 

My fuse panel is wired like the original wiring diagram. But the L of the flasher is connected to the brown terminal.

Original wiring diagram

https://up.picr.de/45228446wq.png

Original wired

https://up.picr.de/45228469tg.jpg

New wired

https://up.picr.de/45228438gz.jpg

Re: Turn signal flasher
 

I checked the wiring. It is as you described. Light blue (blue/white) is the left T/S. Dark blue is the right T/S. The violet wire connects left and right T/S socket. Black wire on each socket will ground to hood or socket housing.

What Violet wire? I said NOTHING about a VIO wire when describing front turn signal socket wiring, You are confusing yourself and confusing me.

And yes, one light blue (blue/white) and one dark blue wire routes from firewall connector to the dash connector.
I don't care what connectors the wires go thru. I only care about you being sure a wire is connected as I describe, point to point.. JUST LIKE THE DIAGRAM.

There is no way I can get any info or confirm anything by looking at the back of your fuse panel. It does not matter what colors you used to build it as long as it is wired functionally like the diagram. I tried to explain where each turn signal switch color goes functionally and used the colors you said you have coming from the switch. Wire the lights as I describe. I don't know all the colors you used for which.

Re: Turn signal flasher
 

Violet wire is connecting the two T/S sockets like in the original diagram but I don't know if I need it.

https://up.picr.de/45228505lc.png

The whole truck was wired according to the original wiring diagram in the correct colors. Only the L of the flasher connects to the brown terminal and not to violet.

Re: Turn signal flasher
 

There are two violets. They are not associated with each other. The one I've been speaking of is from the turn signal switch.
Brown comes from Ignition ACC. It is a switched hot. It goes to fuse panel and "jumps" to flasher X".
Violet comes from T/C switch to fuse panel Flasher "L".

The two violets are very confusing and extra confusing becasue you have separate park bulbs inside headlight. I now understand what you were saying/thinking.

That other violet is for parking lights which are in the headlight. My apologies for not seeing that the idiots at GMC used a violet there also. You must have already wired that violet to the bulbs inside headlight. That VIO does connect both headlight park bulbs together so that they can be turned on by the headlight switch. But NOT the front T/S sockets. They have to be separated to flash from the T/S switch.

Re: Turn signal flasher
 

Answered your questions in blue color

Re: Turn signal flasher
 

I have extensively revised the post you just quoted.. please read. One more time :lolflag:

Also do you agree that your "X" and "L" are wired wrong? and need to be reversed?
In my case the violet wire runs from T/C switch to fuse panel Flasher "X"
In my case the brown wire runs from ignition to fuse panel "L".

Can you change your quote box to the new quote for clarity.

Re: Turn signal flasher
 

one moment

Re: Turn signal flasher
 

Blue color

Re: Turn signal flasher
 

:D

Yes I agree. X and L is not right. Now I have two options:

- change the brown and violet terminal on fuse panel (when I do that it is not according to the origianl wiring diagram)
- buy a new flasher.

Question: is it possible that the flasher is marked wrong with X and L? Are there any differences in the turn signal flashers with the position of X and L?

Re: Turn signal flasher
 

Don't think a flasher will be marked wrong.

Seems like you want to just swap the contacts and with their wires, inside fuse panel if the contacts are removeable.....or cut the wires and swap them with crimp splices. Which will leave a little violet on a brown wire and a little brown on a violet wire. Whatever way to get the job done.

Don't see a need for new flasher?

Ken

Re: Turn signal flasher
 

I'm with you. I will change the contacts in the fuse panel and will try again. Maybe today in the evening when it's not to cold. I think temperature in Arizona is nicer :D
I will report. Thank you so long :thumbsup:

Re: Turn signal flasher
 

Maybe I will see a headline "EVERYTHING WORKS!!!!!"

Talk to you later, going to bed.