Turn signal relay buzzing

[walarson]

My 76 FI bug sedan has a buzzing sound.

When I turn on the right turn signal I get no turn signal lights and the relay makes a pronounced buzzing sound.

Left turn signal lights work fine.

Turn signal relay going bad?

How do I test it?

Thanks in advance.
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1976 FI Beetle Sedan

[walarson]

[bsairhead]

It is telling you.

[ashman40]

Check your bulbs. The corner turn signal bulbs should be a 21W/25W filament bulbs (1156 or 1157). These provide the proper load the stock flasher is expecting. Are you running a stock VW flasher relay?
Could your corner light assembly be miswired with the black/striped turn signal circuit being wired to the weaker 5W parking light bulb?

To troubleshoot turn signals start by disconnecting/removing the turn indicator lamp from the speedometer. Once you have all four corner lamps working as expected, reinstall the indicator lamp and retest.

Are you running LED bulbs (or lower wattage bulbs) in place of the stock incandescent bulbs? The stock flasher relay expect 21W bulbs in each corner. Using lower watt bulbs will cause the flasher relay to quick flash to indicate a bulb has burnt out. Lower the wattage even further and the flasher relay may stop flashing at all.
_________________
AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[walarson]

[bsairhead]

So the lamps "bulbs" are good? Does it do the same thing with the hazard switch on?

[walarson]

[ashman40]

Remove the flasher relay. Using a jumper wire in place of the relay, jumper the #49 and #49a female openings in the relay bridge. This bypasses the flasher relay. The #31 position is left unused.
Leave the speedometer turn indicator lamp disconnected.
Turn the ignition switch ON and move the turn signal lever into the L position. Both front and rear corner turn signal lamps will turn ON and remain ON (no flashing).
Move the turn signal lever into the R position and confirm the right side corner lamps turn on solid. If the lights do not turn ON try wiggling the lever to see if the internal switch contacts are bad.
If the right side corner lamps do not turn ON, remove both right side turn signal bulbs and test that the contact at the bottom of the bulb socket has 12v. If not, there is a disconnect between the turn signal switch and the junction where the E-Flasher switch outputs merge with the turn signal outputs. Look under the steering column for the large black plug with the black/green right side turn signal wire. Follow this wire (not easy) until it merges with the black/green wire coming from the E-Flasher switch plug. Somewhere between these two plugs there is a disconnect.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[walarson]

[ashman40]

[walarson]

[bsairhead]

Sounds like terminal 31 doesn't have a proper ground.

[walarson]

[walarson]

Ok round 2.

My right turn signal/buzzing relay issue has returned.

Left turn signals work fine.

Right turn signals come on but do not flash, but the relay buzzes.

Emergency flashers work fine.

I had a spare flasher relay and installed and got the same results.

I replaced the light bulbs and the fixtures are all new. I replaced a few ground wires and tightened up the remaining grounds with a needle nose.

For fun (desperation) I replaced the emergency flash switch and had the same results.

Thoughts? What am I missing?

Thanks in advance.
_________________
1976 FI Beetle Sedan

[walarson]

[ashman40]

Some suggestions....

Swap the left side turn signal bulbs to the right side and see if the problem moves to the left indicating it is a bulb problem. You say you swapped bulbs but I'm guessing you are using new bulbs. Try testing with known working bulbs.

I suspect there is a difference in the resistance (load) between the left and right side circuits. I'm guessing your '76 is a SB? I'm not sure where the left side and right side corner turn signal wires come together. In the STD Beetles there was a 4-way junction where all the black/green (right) wires came together and another 4-way where the black/white (left) wires did the same. Here you could separate the corner wires and test each for resistance to ground. The path is longer for the rear wires so they show higher resistance, but both front wires thru the bulb filaments should be a similar resistance reading and both rear paths should be similar readings. If you find one path is much lower or higher resistance you have a problem. The higher the resistance the less current flows down the path. The stock flasher relays require a minimum current flow to flash properly. Too little current draw and they will hyper flash to let you know one bulb is out. If the current draw drops even more (eg. 2W LED bulb) the flasher relay will not flash at all.

You could disconnect the wires from the turn signal switch below the steering column as well as disconnect the L and R wires at the E-Flasher switch. This should isolate the left and right sides of the circuit. Testing the resistance on the black/green and black/white wires at the E-Flasher switch should show similar resistance to ground readings.
Next, remove all corner turn signal bulbs and recheck the resistance. Since you remove the bulbs there should no longer be a path to ground and your readings should show infinite resistance (open circuit). If you still show resistance to ground it means there is a short in one of the wires. I don't think this is what your problem is but you can check.
Reinstall one corner bulb at a time and measure the resistance to ground. This resistance will be thru the one bulb. This should give you and idea of the resistance down each path. Both rear paths should have higher but similar resistance readings. The fronts should be less resistance than the rears but should be similar left to right as their paths are similar in length (technically, the fuse box is located closer to the driver's side making the passenger side length slightly longer = slightly more resistance).

_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[walarson]

Greetings.

In the end I purchased a new flasher relay and the problem was solved. I suspected something was wrong when the two existing relays when swapped in each caused slightly different problems.

At least now I have a good collection of spare bulbs.

Appreciate the insights.
_________________
1976 FI Beetle Sedan

[ashman40]

Do you mind me asking what make/part# your new flasher relay is? Is it an LED compatible flasher relay? LED compatible relays work well with a large range of loads from the corner bulbs.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[walarson]

Certainly. This was purchased at O'Reillys for about ten dollars.
_________________
1976 FI Beetle Sedan

[ashman40]

Ahh yes, EP35 flasher relay. Good choice for a modern LED compatible relay. They are readily available and relatively cheap.

_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}