72 Riviera turn signal behaviour

[Guest Chopper]

Hi there

I posted a few weeks ago about having a 72 Riv here in the UK.

I've noticed that the turn signals are behaving erratically (or at least they seem that way to me) and was wondering how they normally work..

At the moment they flash slowly (once every 5 seconds) when no lights are on, every 10 seconds when the side lights are on and every 20 seconds when the headlights are on.

That was from a quick test I just did..I can go check in more detail when I have more time later in the week. Looking after a 12 week old baby at the moment so I can't spend too much time up to my elbows in it..

This isn't good over here. I need them flashing at least once a second to comply with regs.

Any idea on how they should behave and how I might go about changing them?

Many thanks in advance.

[Guest simplyconnected]

Your flasher unit works on current. Flasher units are designed for a certain current range. If you have the correct size and number of bulbs, that current heats a bi-metal strip inside your flasher. Once per second, or so, the bi-metal strip will open, then close. Those flasher units haven't changed for over fifty years.

A problem here in the states is, when we wire our trailers to the car rear light circuit, the flasher goes much too fast because of the added current.

If you have a flasher cycling less than once/sec, there's something wrong. Did you substitute LED's instead of incandescent light bulbs? Did you eliminate a few bulbs, or install the wrong flasher unit?

[Guest Chopper]

Thanks for the quick response!

I've only just bought this and haven't changed a thing on it yet.

It's possible it has been altered by someone when it got over here. It has regular incandescent bulbs, 3 on each side; looks like one for the reverse light, one for the flasher and one for the brake. I'm not sure if they're the correct type or not though.

On another note I've only looked at them myself with the ignition on but the engine not running (late here and I don't want to wake anyone up.. It's a tad noisier than the average UK car ). Not sure if that makes a difference.

[Guest simplyconnected]

Key must be on, back-up lights and brakes don't make a difference. What makes the MOST difference is tight lamp grounds. If the grounds or connections are corroded, your flasher unit will never put out the specified 60-120 flashes per minute.

It is unlikely, but your flasher unit might be bad. They come in two flavors; 2-lamp (station wagon), or 3-lamp (two in the rear, and one in front). The flasher is located near the top of your steering column (not at the fuse box). If you replace yours, get a proper flasher for your lamp setup.

Your turn signal switch interrupts your brake lights. Make sure your bulbs, connectors, and grounds, are good. Usually, GE-1157 bulbs are used for Parking/Brake/Signal lamps. GE-1156 (one-tit) is used for Back-up lamps.

Hope this helps. Dave Dare

[RivNut]

If your Riv is typical of most GM cars from the era, you'll not have separate lamps for the flasher and brake. The reverse light will be a single filament bulb behind a clear lens - you can't mistake it. IF, and I emphasize IF, your Riv is typical, the other two bulbs should be the tail lights, signals, and flashers - all this in two bulbs on each side. Both bulbs on the same side work on the same circuit; two bulbs just make that much more light. Each bulb has two filaments in it, one for the tail lights, and another brighter one that comes on with the turn signal lever ORthe flasher switch. There's a built in canceling mechansim that turns off the brake light when you turn on the turn signal for that side.

Lots of cars from this era are prone to have grounding problems. If your socket grounds throuh the tail light housing which in turn grounds to the body then to the frame, there's a good chance that 40 years worth of corrosion is not letting the circuit create a good ground.

I copied and pasted this from Sylvania's website for your particular car. It shows the proper bulb for your lights. Make sure that every bulb in the entire car is working, not enough resistance and your signals will work slowly.

For the entire list, go to the Sylvania website.

Hope this helps some.

1972 BUICK Riviera

Low beam headlamp

H5006

High beam headlamp

H5001

Parking light

1157A

1157AST Silverstar Signal Lighting: Complete the Look: Crisp, Clean, Style

1157ALL Long Life Upgrade: Up to twice the life of the standard lamp

Front turn signal

1157A

1157AST Silverstar Signal Lighting: Complete the Look: Crisp, Clean, Style

1157ALL Long Life Upgrade: Up to twice the life of the standard lamp

Rear turn signal

1157

1157LL Long Life Upgrade: Up to twice the life of the standard lamp

Tail light

1157

1157LL Long Life Upgrade: Up to twice the life of the standard lamp

Stop light

1157

1157LL Long Life Upgrade: Up to twice the life of the standard lamp

License plate

194

194LL Long Life Upgrade: Up to twice the life of the standard lamp

67/97

Back up light

1156

1156LL Long Life Upgrade: Up to twice the life of the standard lamp

[Guest Chopper]

Wow.. Thanks again for the detailed info! I'll check that site out and order a bunch of extras anyway..

I'll let you know if I figure it out! Thanks.

[Guest Chopper]

Hmm.. I'm still waiting for the bulbs. They should be here soon.

I have noticed they work fine when you put on the hazard lights (that'ss what we call them over here. It's the stalk on the steering column you pull out to get the to flash at the same time) though. One blink a second, no probs.

The indicators (turn signals) are still very erratic though.

I'll have a look at the connections and see if they're a bit old and rusty.

[Guest Chopper]

Well thanks for the help guys.

I used a sledgehammer to crack a nut in the end and replaced the bulbs, cleaned all the grounds I could find and replaced the fuse and flasher relay.

Works fine now!

Put a 4 bulb flasher relay in as well as it was just a 3 before. Not sure if that made a difference.

Interestingly when I removed the fuse for the turn signals one head light and a full beam lamp wouldn't work. They're fine now I've replaced the fuse oddly.