[roger bentley]

1969 Catalina. Turn signals work but when I turn parking lights on they slow down and when I turn headlights on they stop. I have changed flasher and re-did the grounds for lights both front and rear to no avail. Any other ideas? Not to good with electrical at all. Is there a main ground I should be looking for? If so, where should I look? Any help would be great. Thanks.

[1969GiPper]

Your main ground is the negative battery cable connection to the left side cylinder head bolt/stud. That grounds the engine. Unless I’m wrong everything else in 1969 (e.g. body) eventually gets it’s ground from the ground straps that go from the rear of the engine to the firewall. If those are bad or missing the electricity will try to find another way (e.g. via a transmission shift cable). Make a couple of jumper wires and connect them between the engine and body and see if things get better.

[roger bentley]

Will try that. Thanks. Will report back.

[johnta1]

Battery cable from battery to engine?

When the headlights are turned on, all the lights go out or the headlights only stay on?

All the tail lights and front lights work?

When using the turn signal, does the light go out or just quits blinking when the problem happens?

I'd also look at the dash panel grounds.

[roger bentley]

Engine ground to the head good. When headlights are on all lights work. All tail lights and front lights work. Turn signal just stops blinking......light stays on.

[johnta1]

I'd say the flasher unit is wrong/bad?


Does it say 'Heavy Duty' or something like that?

[roger bentley]

tried 2 different flashers.

[johnta1]

Most people think the 'Heavy Duty' will be better so they buy them.

It is not what needs to be used.

Look for what should be in it.
There is a service bulletin on this also.

[roger bentley]

Went and bought another regular duty flasher and 2 ground straps. Going to put them all on tomorrow. Fingers crossed

[Heybuck]

I had similar issues years back with my '66GP. I pulled an electronic flash can out of a Nissan car and problem solved.

But I also had ground problems with the dashboard lights. The poor ground would fail intermittently with the result that all indicator bulbs would glow faintly.

By fixing both above items, I've never had another problem however while I was going through the wiring, I also fitted relay's to the headlights. Hid the relay's and wiring up behind the fender so in effect I have removed virtually all the load running through the loom. Super bright headlights and the dash wiring is cold to the touch.

[Geoff]

Sounds like a lot of voltage drop in the wiring. Extra electrical load of h/lights on is reducing voltage. If you are happy with the rest of the electrics, an electronic flasher should fix the issue as they are not voltage dependant.
I would also check the voltage at the battery, engine idling, all lights on. Should be over 13v. If less you might have a charging problem.

[HWYSTR455]

Check all the bulb sockets too. Could be they are high resistance, and once the load goes high(er) to say X, it's not enough to jump the high resistance area.

.

[george kujanski]

With poor grounds or excessive resistance in the electrical loads, a standard flasher will slow down.

The way the flashers work is there is a bimetallic strip in there that is heated by the load current. When heated, it bends, breaking a contact. It cools, re-sestablishes the contact, reheats, breaks, the cycle repeats.

For the same reason, if say, a trailer is connected to the tailight system the flasher speeds up because there is MORE current in that circuit. Therein is the use of the "heavy duty" flasher.

The side effect of the flasher not flashing typically indicates a bad bulb somewhere.

George

[roger bentley]

Today I put in a new flasher and checked the grounds from battery to engine, engine to firewall and firewall to frame. All good. It now all works fine when the car is running. When the car isn't running, turn signals work fine, however, if I turn the headlights on they slow down considerably. That's good enough for me. Thanks for all your help and ideas. This forum is the greatest!

[Scott Thelander]

sweeeeeeeeeeet
but
it
still sounds like a whimpy battery ...........