TheSamba.com :: View topic - Flasher relay

Thu Apr 01, 2021 1:52 pm

According to the flow wiring diagrams I have (for our 1974 KG Coupe), power to the flasher relay comes from two sources depending on the position of the emergency flasher switch – either the switch itself (when on) or from the coil through fuse box during normal operations.

So far so good. I have power to the relay with the emergency switch on and off. But neither my hazards nor my turn signals work. I have power at the relay at the 49 position (input) but no power at the 49a (output) position.

The circuit doesn’t look too complicated. Power goes to the relay then to the switches then to the bulbs. I engage the switch and I expected that to complete the circuit but there is no power at the 49a position on the relay.

When should power leave the relay? When should 49a be hot? I assumed when the switch was engaged.

BTW all the lights work - running and headlights and the relay is new.

Thanks,
Matt

Thu Apr 01, 2021 2:39 pm

Hey Matt, just for shits and giggles, try pulling the emergency flasher and then move the turn signal down or up and see if anything comes on. Try it with the key off and on. I had a problem once where that was the only way I could activate the emergency flashers, clearly a wiring problem somewhere that I eventually figured out. I know it sounds stupid, but I actually had that problem. And no, this isn't an April fools joke!!
Jeff

Fri Apr 02, 2021 7:29 am

You might have a bad relay. The way I understand it (and I could be wrong because I've never quite understood fully how flasher relays operate internally) is that 49a should always be energized if the relay terminal + has 12V. It's the hazard switch (or turn signal switch) that then sends 12V to the turn signal lamps, which are already connected to ground, to complete the circuit.

And just to be sure, terminal 31 on the flasher relay is grounded, correct?

I think the body of the flasher switch also needs to be grounded to the dash. If you have fresh paint, you might need to scrape a little away to bare metal to allow the flasher switch to make contact with the body ground.

djkeev wrote:
________________

When the key is OFF and the 4 way switch is OFF .......
There is power to Terminal 30 via a Red Always Hot Wire from fuse 9.

*************
When the key is OFF and the 4 way switch is ON .......
Power from terminal 30 is transferred to Terminal (+).
12v is transmitted via a WHITE wire from Switch Terminal (+) to the Flasher Relay Terminal (+).
Flasher Terminal (+) energizes Flasher Terminal 49a
Power from Flasher Terminal 49a is transferred via a BLUE wire to Switch Terminal 49a
Switch 49a energizes Switch Terminals L & R
Terminals L & R go to the turn signal bulb completing the circuit.

*************
When the Key is ON and the 4 way Switch is OFF
There is still power at Switch Terminal 30 because it is an unswitched feed.
The Key energizes Switch Terminal 15 via a BLACK wire from fuse 1 or 2.
Terminal 15 energizes Switch Terminal (+)
Switch Terminal (+) energizes Flasher Relay Terminal (+) via a WHITE wire
Relay Terminal (+) energizes Relay Terminal 49a
Relay Terminal 49a energizes Switch Terminal 49a via a BLUE wire

************
When the Key is ON and the 4 way Switch is turned ON
There is still power at Switch Terminal 30 because it is an unswitched feed.
The Key energizes Switch Terminal 15 via a BLACK wire.
Terminal 15 energizes Switch Terminal (+)
Switch Terminal (+) energizes Flasher Relay Terminal (+) via a WHITE wire
Relay Terminal (+) energizes Relay Terminal 49a
Relay Terminal 49a energizes Switch Terminal 49a via a BLUE wire
PLUS Switch Terminals L & R are energized which feed to the Turn signal bulbs.

***********
NOTE:
The Flasher Relay is ALWAYS POWERED when the key is on.
It does not operate until the circuit is completed by pulling out the 4 way flasher knob.

TURN SIGNALS
_________________

Turn Signals operate only with the Key ON.
When the Key is turned ON.....
All of the 4 way Terminals are activated exactly as in Key ON 4 way OFF listed above.
What I haven't yet mentioned is that the BLUE wire from Flasher 49a to Switch 49a has a junction where it joins a Black/Green/White wire that feeds the Turn Signal Switch at Terminal 54

When the Turn Signal Switch is activated either left or right, the bulbs are activated on that side completing the circuit.

Simple once you (I) understand it!

Dave

Fri Apr 02, 2021 10:41 am

Quote: Hey Matt, just for shits and giggles, try pulling the emergency flasher and then move the turn signal down or up and see if anything comes on. Try it with the key off and on. I had a problem once where that was the only way I could activate the emergency flashers, clearly a wiring problem somewhere that I eventually figured out. I know it sounds stupid, but I actually had that problem. And no, this isn't an April fools joke!!
Jeff

Yeah, can’t hurt but no luck.

Quote: Era Vulgaris:
You might have a bad relay. The way I understand it (and I could be wrong because I've never quite understood fully how flasher relays operate internally) is that 49a should always be energized if the relay terminal + has 12V. It's the hazard switch (or turn signal switch) that then sends 12V to the turn signal lamps, which are already connected to ground, to complete the circuit.

And just to be sure, terminal 31 on the flasher relay is grounded, correct?

I think the body of the flasher switch also needs to be grounded to the dash. If you have fresh paint, you might need to scrape a little away to bare metal to allow the flasher switch to make contact with the body ground.

That is how I understand it – 49a is always energized when + (my relay is labeled 49) is powered. And Djkeev’s description is exactly how I understand it to work (after what seems like hours staring at the flow diagrams). And yes 31 on the flasher relay is ground and mine is well grounded to a clean chassis point that I think is called the “Christmas tree”.

However my 49a is not powered with the emergency switch in any position. It’s a new flasher that I bought just to be safe as I was chasing multiple problems. So I put the old relay back in. 49a is now hot. Left side turn signals work. Nice clicking sound from the relay. Right side turn signals do not work. So I think I’ve fixed one problem (bad new relay) and am moving onto the next problem.

The current situation:

No turn signals on: + is hot and 49a is hot. Relay buzzes when I touch the test light to 49a and the test light comes on brightly.

Left turn signal on: + is hot of course and 49a alternates between hot and cold as expected. Nice bright test light. Relay clicks but does not buzz.

Right turn signal on: + is hot. Relay buzzes loudly and 49a glows very dimly and steadily, not flashing.

So something is wrong with the right turn signal circuit. Something downstream of the relay. I’m going to go down and relook all the right side connections and grounds but open to all suggestions if someone has seen this before.

Thanks,
Matt

Fri Apr 02, 2021 11:54 am

Couple additions. First hazards don’t work at all – right or left. Relay buzzes. It could be a problem on the right is affecting the whole system…?

Side note: I read online (so obviously it’s true) that a buzzing relay could be a bad relay or it’s not getting enough power. I think the not enough power is my problem on the right side.

I checked the output from the turn signal switch. On a 1974 model there is a plug that connects to the underside of the steering column. I pulled it partway out and put the test light to the prongs labeled R and L. With the left turn signals on, the L prong lit up the test light and blinked appropriately. With the right turn signals on, the R prong lit up the test light very dimly and again steadily, just like above when I tested the 49a on the relay with the right turn signals on. Not enough power to fully activate the relay?

So the turn signal switch is getting power. 49a on the switch is connected to 49a on both the relay and the emergency switch. All good there. And left side works. But the switch does not seem to be sending enough power to the right side.

Bad turn signal switch? But if so, why would this affect the hazards? According to the flow diagram for 1974, the hazards switch, when activated, should bypass the turn signal switch…

Unless the problem is downstream of both the turn signal and emergency switches and on the right side. Something on the right side is causing a bad connection in the circuit? There’s just not much left to check.

Fri Apr 02, 2021 12:23 pm

Could be a poor or unexpected earth in the system on that circuit. If the relay is buzzing and your test lamp is glowing dimly it sounds to me like a poor earth. When you say "hot", have you checked with a multimeter that you are getting a stable 12V with respect to a good known earth (so try to go directly onto the chassis) and does it stay stable when you activate any of the switches?

Fri Apr 02, 2021 1:02 pm

I just checked with a multimeter. The “+” (on mine the 49) position on the relay to a good chassis ground is ~9.5v and steady. With the left (working) turn signals on, that drops to ~9v and bounces +/- .5v maybe less. Seems to be reacting to the on/off of the relay. With the right (non-working) turn signals on, that drops to ~6v and bounces again +/- .5v.

Not sure what that means…

I was assuming a dim test light meant poor current and bright test light meant good strong current without really quantifying it.

I suspect you are right. Ground / earth is the usual suspect... I'll keep looking.

Thanks.

Fri Apr 02, 2021 1:46 pm

Yeah, that sounds like an unexpected path to earth there. 9.5V not right, 6V definitely not right. You can remove the fuse and without actuating any of the switches check the path from the "cold" end of the fuse to the relay, checking the resistance to chassis at each of those points and any junctions. If nothing there, then start looking from the "hot" side of the fuse.

Fri Apr 02, 2021 2:23 pm

I just checked the battery charger I am using to power the system. It is putting out ~9.5v at the 2amp setting. I was nervous about connecting a brand new battery to the system when I clearly have some problems. That’s a lot of amps. Do you think using the charger is a problem? The charger is powering the lights including the headlights. I do have some things working.

So perhaps the left is working okay even though I’m only at 9.5v? But clearly a problem on the right.
Quote:
You can remove the fuse and without actuating any of the switches check the path from the "cold" end of the fuse to the relay, checking the resistance to chassis at each of those points and any junctions. If nothing there, then start looking from the "hot" side of the fuse.

This is new to me. I’m going to have to think about how to do what you describe…

Fri Apr 02, 2021 3:12 pm

Sofia74 wrote: I just checked the battery charger I am using to power the system. It is putting out ~9.5v at the 2amp setting. I was nervous about connecting a brand new battery to the system when I clearly have some problems. That’s a lot of amps. Do you think using the charger is a problem? .

I think each light is 12 watts and there’s four going off at a time. 48 watts would need 4 amps. 2A is only 24 watts which would be okay if the bulbs were 6 watts each.

The 2A setting means it is current limited to 2A. If you have too much current draw, extra things turned on, or a short, or even wiring mistake, then battery charger will drop voltage if it can’t deliver the current demand but the current limit will save you from burning out your wires.

I’d be expecting voltages above 13.8 for an unloaded charger and 12ish under load. Use a higher current setting if you are sure there are no shorts.

Clip the battery charger’s leads directly to your volt meter ie without a load, and measure a value above 12 volts. If not, get it replaced ‘cos it won’t be fit for purpose.

Nicholas

Fri Apr 02, 2021 4:23 pm

Aha. That indeed could be the issue.

Is there a battery connected at all? Or are you only going off the charger?

If you are going off the charger and it is a battery tender/trickle charger type the load of lights etc may be too much for the battery charger to supply with its current settings. The 12V rail will collapse down. It'll "wiggle" up and down as other consumers turn on and off (such as a light attempting to switch on and off) and it may not even be enough to drive the coil on a relay if it's dropping (hence the buzzing coil).

Sat Apr 03, 2021 4:27 pm

Quote: I think each light is 12 watts and there’s four going off at a time. 48 watts would need 4 amps. 2A is only 24 watts which would be okay if the bulbs were 6 watts each.

The 2A setting means it is current limited to 2A. If you have too much current draw, extra things turned on, or a short, or even wiring mistake, then battery charger will drop voltage if it can’t deliver the current demand but the current limit will save you from burning out your wires.

I’d be expecting voltages above 13.8 for an unloaded charger and 12ish under load. Use a higher current setting if you are sure there are no shorts.

Clip the battery charger’s leads directly to your volt meter ie without a load, and measure a value above 12 volts. If not, get it replaced ‘cos it won’t be fit for purpose.

Nicholas

Okay, just checked. Unloaded charger putting out 9.6v at 2amp setting. And 11.4v at the 12amp setting also unloaded. I am using the 2 amp setting.

I rummaged through the packaging and the bulbs are 8 watts each. So four turn signal bulbs would need 24 watts. And I am currently putting out 2amps X 9.5v = 19 watts. Obviously lower than the 24 watts required.

So the hazards wouldn’t work. Not enough wattage. Okay.

But one problem remains - left side turn signals work but the right side don’t. In this case it’s not a lack of wattage.

Quote: Aha. That indeed could be the issue.

Is there a battery connected at all? Or are you only going off the charger?

If you are going off the charger and it is a battery tender/trickle charger type the load of lights etc may be too much for the battery charger to supply with its current settings. The 12V rail will collapse down. It'll "wiggle" up and down as other consumers turn on and off (such as a light attempting to switch on and off) and it may not even be enough to drive the coil on a relay if it's dropping (hence the buzzing coil).

There is no battery connected, just the charger. It is a Schumacher charger with 2 / 12 / 75 amp settings. Slow and fast charging (2 & 12 amps) and a 75 amp starting mode. I am using the 2 amp setting. So far it has powered what I tested - running lights and headlights (only one head light is installed), brake lights and dash lights. And left side turn signals - right side not working. Not enough wattage to power the hazards it seems.

I do not have the engine installed. I have the charger positive connected to the main red power and the black wire that should come off the coil. The transmission mount provides a good ground. I am very nervous connecting a 330 CCA battery in its place. That’s a lot of amps. Would I hook it up the same way? Or does the using a battery assume the engine is installed? How should I hook it up?

Quote: Use a higher current setting if you are sure there are no shorts.

I just had a blown fuse when I pulled on the emergency switch. Not sure why it did that but hadn’t earlier. It was an 8 amp fuse. So I am not sure that I have no shorts… If I had no shorts would the 12 amp setting on the charger be recommended?

It seems my problems are:

Should I be using a battery instead of a charger and if so how do I hook it up?
Do I have a problem with my charger given the voltage output?
What is wrong with my right side turn signals?
Hazards blew a fuse – should I be using an 8 or 16 amp fuse? Or do I have other problems?
If I continue to use the charger, should I use the 12 amp setting?

I'll be away from the car for a couple weeks but open to any suggestions to include where I can learn more...

Thanks,
Matt

Sat Apr 03, 2021 4:42 pm

Matt, If you are blowing a fuse, then like someone mentioned before, you have a ground problem or one of your wires is not hooked correctly. I had that problem and kept blowing fuses every time I pulled my headlight switch. I checked every wire from each point, headlights to fuse, turn signals to fuse, rear lights to fuse, I found I had one wire misplaced and one grounding problem. Just have to go back and trace each individual component.

Also, the CCA for your battery is Cold Cranking Amps, this is how much it juices your starter solenoid at starting. Your battery is only 12volts when operating systems. When I check my lights, I connect direct to battery and it works perfectly. Here's how I hook up.

I made a little jump wire, green, from the red wire coming into the engine, alt/gen connector(?), or if you have a different battery cable, connect the red wire directly to it. I grounded my negative to the trans strap, or whatever it's called..just ground it good to the chassis somewhere.

Try that when you get back to it. Just make sure battery is fully charged, and it will last pretty much as long as you need it just checking lights.
Jeff

Sat Apr 03, 2021 5:23 pm

Quit dicking around with a charger and connect up a battery.

What sort of bulbs are you using? If incandescent bulbs, the turn signal bulbs should be 21 watts, not 8. (to the extent that any of them are dual filament bulbs, one filament will be 5 watts - running lights - and the other filament will be 21 watts - turn signal.)

If LEDs, that causes other problems.

If your bulbs are non-stock spec and don't provide the proper load on the relay, the relay won't flash.

Sat Apr 03, 2021 5:49 pm

I'd hesitate to connect a 12V battery with a potential grounding issue (there's a pun there, if you're so inclined).

Certainly if you're blowing fuses I would not connect a battery until the issue is identified and corrected.

The charger voltage will drop if there is a short and it is reaching its current limit.

"CCA" = Cold Cranking Amps but that is the amperage deliverable by the battery. If there is a short to ground somewhere, that could cause a blown fuse, but could also potentially burn a wire and cause other issues. So I think caution is better exercised here until the root cause of the short is identified.

Use the multimeter in the manner I suggested, check for resistance to chassis at various points (terminals, junctions, relays, earth points).

Unless you are using LEDs, incandescent bulbs ought to light dimly when the rail is fewer than expected volts. I think it is just going to be a case of patience and checking various points on the harness.

Which fuse blew when you pulled the switch? Was it the fuse for the indicators themselves? (as opposed to the dash lamps) If that was the case, then I would carefully inspect the harness going to the indicators fore and aft.