'65 Left front turn signal not working

[65VerdeGS]

I'm reaching out for ideas to solve my inoperative front driver's side turn signal problem.

 

After reading just about every post on this Forum on the subject of turn signals, I dove in to try to find out why mine aren't working right.  All signals, tail, and brake lights work properly, EXCEPT, the front left signal will not 'blink'.

 

This problem arose last year and I posted about it then.  I got good suggestions about ensuring good grounding on the bulb socket.  I wasn't able to determine what the problem was, and a few months later was pleasantly surprised when the left front signal suddenly started working again!  My joy was short lived, however, as it has now stopped working once more. So, with social isolation in full force, I set about tackling this little problem again..  

 

Armed with my research from this Forum, here's what I did last night:

 

1. Checked turn signal cable - mine is fine, the sheath does not appear broken. and the wire doesn't move when the wheel is tilted through its positions.
2. Removed signal switch, took it apart it and cleaned all contacts using electrical contact cleaner.  It didn't look too bad inside...  Getting the 3 triangular things back onto their springs and putting the thing back together was a bit tricky, but I managed it.  Someone mentioned there also being 4 very small ball bearings inside this switch. I never saw any ball bearings, nor did these fall out upon disassembly.  Maybe these are inside a portion of the switch I didn't take apart?
3. Reattached turn signal to steering column and adjusted it per Tom Mooney's good instructions.
4. Tested signals - all good EXCEPT the front LH (drat!) - nothing changed!
5. Placed temporary wire from LF bulb to bumper - I removed front LH parking light metal grille and lamp housing and placed a temporary wire from the base of the bulb to the bumper in hopes of ensuring a better ground.  This made no difference.
6. Used an electrical probe tester to see if power was getting to the bright filament of the bulb socket.  I couldn't get behind the pot metal bulb assembly itself (more disassembly would be needed) so I followed the wires up to the engine compartment near the battery where they're clipped to the fender near at a plastic connector.  From here the wires get fed to other wires going to the engine compartment harness.  I could not get the icepick probe to pierce the insulation, being old and rather 'stiff'.  Instead, I managed to stab myself my finger with the probe (OUCH!).   In the alternate, I stuck the probe into the connection socket (see photo)  Result: Power is fed to the wire feeding the low intensity side of the bulb (brown wire), when the parking lights are engaged.  Engaging the turn signal did NOT feed power to the blue wire which feeds the bright filament.  Does this mean the problem is 'upstream' of the bulb socket, e.g. wiring towards the fuse block and on to the turn signal switch?
7. 

 

The Shop Manual says "If signal works properly on one side, but there is no signal at front, rear, or indicator light on other side, trouble is in signal switch."   So, is the defect in my turn signal switch?  Is there anything else I should check to exclude other causes?   

 

If I need a new turn signal switch - where can I get one?   Looks like this is a hard to find part.  None of the usual Buick parts places seem to carry it. 

 

Summit Racing lists the following as fitting a '65 Riviera with tilt steering:

Except that a posted review said the following:

Has anyone used this switch and can verify it works?  For the light duty it's likely to receive from me, perhaps I could find a way to attach it securely enough to the steering mast.

 

Any and all advice gratefully accepted! 

[KongaMan]

Move to California.  You'll fit right in; none of the cars out here have working turn signals.

 

But if you must...  Initial suspicion would focus on a corroded connector.  Check the circuit at the firewall, then proceed either back to the switch or forward to the bulb.

[Hazdaz]

Corrosion or grounding issue. 

 

I almost guarantee it is one of those two things.

[bodayguy]

Yeah I would make sure the bulb is connecting to the housing properly. I think the ground is actually made partly with the metal housing? Make sure it’s not corroded.

 

if the rear blinker is working then you know it’s not the switch 

Edited April 1, 2020 by bodayguy (see edit history)

[telriv]

There ARE 4 balls in there to help the switch slide.  I doubt very much if they are your problem though.

[Seafoam65]

You need to probe the wire for left front turn signal with your test light where it comes out of the switch. If you have power there,

you need to check it where it comes out of the bulkhead connector at the firewall under the hood. don't just condemn the switch until you

probe the wire at the switch to verify it is bad.

[KongaMan]

2 minutes ago, Seafoam65 said:

You need to probe the wire for left front turn signal with your test light where it comes out of the switch. If you have power there,

you need to check it where it comes out of the bulkhead connector at the firewall under the hood. don't just condemn the switch until you

probe the wire at the switch to verify it is bad.

He has power there; the left rear works.  That would indicate the switch is good.

[Seafoam65]

On every GM car I've ever worked on, the front and rear turn signals are totally different circuits, which

would mean that the rear working doesn't mean the switch is good. The wire needs to be checked for power that

goes out to the left front turn signal.......a lot of times the problem is at the connector where it plugs into the turn signal switch.

[RivNut]

The brake lights and the rear turn signals use the same filament in the bulb.  The rear signals have to be on a separate circuit. Otherwise your front signals would also act as brake lights.

[KongaMan]

Yeah, I was just going to post that. 😛

 

I'd still tend to bet on corrosion, though. But before you go hi-tech and start jamming probes willy-nilly, try wiggling connectors and pulling them apart and putting them back together.

Edited April 1, 2020 by KongaMan (see edit history)

[65VerdeGS]

Thanks guys - you may be on to something!

 

I'll wriggle under the dash (again - I've done it enough times to be quite adept at it by now) and fuss with the signal switch connector to see if wriggling it will bring the circuit back to life.  Also, will check the bulkhead connector under the hood. 

 

I hope the wiring from the switch to the bulkhead is identified in the Shop Manual or I won't know which of the 6 wires sends power to the front left signal..  Oh, could do this by elimination, but I don't think the wife has the patience to be my eyes on the outside while I fiddle under the dash to find the offending wire. 

 

Update to follow...👀

 

[RivNut]

I'll put my money on the wires that go into the backs of the sockets.  As the wires age they will harden and not allow the tips to contact the base of the bulb.  Those contacts are spring loaded and if the harness wires have hardened the contacts may get pushed back on installation of the bulb but the springs can't overcome the hardened wires and spring back into contact with the bulb.

 

Has the original poster taken a circuit tester to the sockets yet?

[65VerdeGS]

Hi Ed,

 

Thanks for your input.  I'm the OP.  I did check the offending socket last year.  I can't recall if the contacts were springy, or not.  My circuit tester confirmed there was no power to the contact that ignites the bright filament. 

 

That socket is the original 55 year old unit and it was somewhat corroded.  So, I took some steel wool and removed whatever corrosion I could get to. 

 

Another hassle is the bulb is very difficult to replace.  I usually wind up breaking the bulb when trying to remove it.  Is there any sort of 'lube' that can be used to make bulb Re & Re easier?  Also, the bulb doesn't sit well in the socket and I've had to cram a piece of crud around the base of the bulb to get it to make proper contact. 

 

I've read here that these sockets can be a source of trouble, so replacing mine will be a next step.  I don't have a spare bulb socket on hand, so that's another thing to get if tonight's "wiggling of wires" doesn't solve my no front left signal problem.

 

Cheers,

 

[RivNut]

A coating of Dielectric Grease is good for making easy installation  and removal,of the bulbs, protecting against corrosion, as well as helping make contact would be a good idea.

 

[KongaMan]

2 hours ago, RivNut said:

I'll put my money on the wires that go into the backs of the sockets.  As the wires age they will harden and not allow the tips to contact the base of the bulb.  Those contacts are spring loaded and if the harness wires have hardened the contacts may get pushed back on installation of the bulb but the springs can't overcome the hardened wires and spring back into contact with the bulb.

 

I thought he'd checked that, but...

 

2 hours ago, 65VerdeGS said:

Another hassle is the bulb is very difficult to replace.  I usually wind up breaking the bulb when trying to remove it.  Is there any sort of 'lube' that can be used to make bulb Re & Re easier?  Also, the bulb doesn't sit well in the socket and I've had to cram a piece of crud around the base of the bulb to get it to make proper contact. 

 

That sounds exactly like what Ed's referring to.  Unfortunately, the fix involves getting access to the back of the socket (which is a PITA for this one).  The contacts on the end of the wire are spring loaded.  They're supposed to move in and out to contact the terminals on the bulb.  The wire gets hard and they don't move (locked into the out position so you have to push harder and twist more and you break the bulbs; then when yo put the new bulb in they don't sprig back out).  You can sometimes free them up by pushing them back and forth a few times (a little lube will help).  If that's a no-go or the insulation is rock hard, cut the wire 1/2" or so from the socket, desolder the stub from the terminal, then solder the terminal on to the fresh end of the wire.  (Be sure to push the wire back through the socket before you solder the terminal on.  Ask me how I know this.)  It's usually only a little bit of wire that gets hard, perhaps from the heat of the bulb, so getting rid of that section should do you.

Edited April 2, 2020 by KongaMan (see edit history)

[RivNut]

I knew that I'd seen this before but it took me a while to find it.  It's worth watching.  And aren't we lucky, they just happen to be making this repair to a 1965 Riviera turn signal. 😃

 

 

[Seafoam65]

Great video Ed! Thanks for posting. That really ought to be a sticky on Mr. Earl's sticky page.

[65VerdeGS]

Thanks Ed for posting the video, very helpful!  How coincidental the guy used a '65 Riv front turn signal hosing to demonstrate the fix!

 

But fIrst I'll try KongaMan's tip to see if I can free up the original wires with some lube.  Maybe WD40 would help?  If that doesn't do it

then I'll do the repair as shown in the video.

 

But to back up just a bit - if the problem is the frozen contacts in the socket, shouldn't I confirm that current is actually getting to the socket contacts first by using my circuit tester before tearing into the socket repair?  Here's the procedure I'm thinking to follow:

1. Remove bulb
2. Turn on parking lights
3. Tun on left front signal
4. Place tester probe at each contact in the socket, with the tester grounded to the car's bumper (or battery?).  The tester should light at each contact to indicate current is getting to the socket terminals (steady for the parking light, flashing at the signal contact.)

I'm hoping this procedure will exclude the turn signal switch as the source of the problem.

 

Do you  agree with the above suggested testing procedure?

 

Thanks, and have a good weekend, everyone!

 

 

 

[RivNut]

It's especially coincidental that they used a Buick part and their name is Mustang Project.

1 - 4 is correct.  I think that I'd just check out one circuit at a time rather than both simultaneously.  

Good luck.

[65VerdeGS]

How do I remove the front turn signal housing to replace, repair the bulb socket?

 

I can't see an obvious way to get to the rear of the housing to remove it.  Does part of the wheel well liner have to come out first?

 

In pawing through some old boxes of parts I found an entire front turn signal housing with cover, grille, etc.  The contacts in this housing do move back & forth on their little springs.  So, if I can't get what's on the car now to work because the contacts are seized, my backup plan is now to replace the entire housing for the spare which has a good socket.

 

Thanks for all your advice and tips.

 

 

[RivNut]

Perhaps you can figure it out by looking at the holes in the back of the extra housing you found. ???

[65VerdeGS]

Last night I did some more troubleshooting of the left front turn signal that fails to flash.

 

I traced the wires that come from the turn signal housing up the fender to a junction where they're plugged in via a connector to the engine compartment harness on each side (Left and Right).

 

Using my handy test probe I checked the connector from the turn signal housing where it's plugged into the wiring harness in the engine compartment.  I first checked the working Right (passenger) side to determine which wire feeds which filament in the bulb.  Here's what each wire feeds:

 

PURPLE - parking lamp

BLUE - turn signal

 

Then I turned on the parking lamps and engaged the Right hand turn signal.  When I probed with my tester to the Purple wire, the tester lamp glowed solid.  When put to the Blue wire, the tester lamp flashed in unison with the turn signal flasher.  All good.

Next, I did the same for the Left side.  All good with the Purple wire (parking light), but NOTHING coming from the Blue (turn signal) wire.

 

I tried this same test various times, and the results were always the same.

 

This tells me the problem is between the connector at the fender and the turn signal switch, not the bulb socket or wiring behind it.

 

So, before I condemn the turn signal switch, anywhere else I can test to isolate the problem?

 

How would I test the turn signal switch itself?  I don't think there is enough room to get the ice pick probe in to the back of the switch to test it this way.  

 

I do have a small Voltmeter - how would I use this to test the operation of the signal switch?

 

Sigh... 😑

 

[KongaMan]

17 minutes ago, 65VerdeGS said:

Last night I did some more troubleshooting of the left front turn signal that fails to flash.

 

I traced the wires that come from the turn signal housing up the fender to a junction where they're plugged in via a connector to the engine compartment harness on each side (Left and Right).

 

Using my handy test probe I checked the connector from the turn signal housing where it's plugged into the wiring harness in the engine compartment.  I first checked the working Right (passenger) side to determine which wire feeds which filament in the bulb.  Here's what each wire feeds:

 

PURPLE - parking lamp

BLUE - turn signal

 

Then I turned on the parking lamps and engaged the Right hand turn signal.  When I probed with my tester to the Purple wire, the tester lamp glowed solid.  When put to the Blue wire, the tester lamp flashed in unison with the turn signal flasher.  All good.

Next, I did the same for the Left side.  All good with the Purple wire (parking light), but NOTHING coming from the Blue (turn signal) wire.

The dark blue wire is for the right turn signal.  That's a different circuit than the left turn signal.  You need to find and probe the light blue wire to check voltage to the left signal.

[65VerdeGS]

Hi KongaMan,

 

My ability to detect colors isn't so great and the wiring is old and somewhat faded...

 

Here are two pics of the wires I tested. 

 

This one is from the left (driver) side:

Here I'm testing the wire that feeds the parking light filament - tester glows steady, as does the bulb.

When I turned the signal on to this side and put the tester probe to the other wire NOTHING happens.

 

So, I then tested the Right (passenger) side.  Here you can't see which wire I've inserted the probe into because the connector wired to the turn signal housing isn't long enough to pull it out beyond the top edge of the fender.

On this side when I tested the wire feeding the parking lamp the tester lights up solid.  When I tested the dark blue (?) wire which feeds the turn signal filament, the test light glows in unison with the signal bulb flashing. 

 

This was my way to find out if the problem is 'upstream' from the lamp socket and associated wiring.  From this I take it the problem is with the wiring to the signal switch, or inside the signal switch itself.

 

Your thoughts?

 

 

[RivNut]

Do as Salmon do. Start moving upstream.  😁

[KongaMan]

Probe the backside of firewall connector.  If that's a no-go, unplug it and probe the other half.  The goal here is to exhaust every possible failure point before having to go upside down under the dash.