Goofy lights

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cmm24601
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Joined: Sat Jun 04, 2016 5:28 pm

Goofy lights

Post #1 by cmm24601 » Sun Jul 09, 2017 10:05 pm

I'm having some serious issues with my instrument panel on my 69 Mustang Grande. The printed circuit is in good shape, replaced recently. I also replaced the constant voltage regulator. I replaced all the bulbs with LEDs.

The main issue is with the headlights and turn signals. The turn signal indicators do not light when the signals are blinking. They do occasionally light when cranking the car. Several other lights are not on, like the high beam indicator.

The headlights are drawing power from the turn signals and the turn signals are effecting all the lights. The rate of blinking slows down when the headlights are on and all the lights blink with them.

Lastly, the fuel gauge goes out intermittently.

Is the headlight switch going bad? The voltage regulator?
1969 Mustang Grande
250 inline 6
Automatic Transmission
Autolite 1101 Carb

cmm24601
Registered User
Posts: 60
Joined: Sat Jun 04, 2016 5:28 pm

Re: Goofy lights

Post #2 by cmm24601 » Mon Jul 10, 2017 9:48 pm

I replaced the LED bulbs with the regular bulbs (glad I saved them) and the dash lights all work. Turn signal indicators too. The headlamps still cause the turn signals to blink slower and the lights dim with them. I'm thinking the headlamp switch is going bad.
1969 Mustang Grande
250 inline 6
Automatic Transmission
Autolite 1101 Carb

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B RON CO
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Re: Goofy lights

Post #3 by B RON CO » Wed Jul 12, 2017 8:18 am

Hi, maybe when the headlights come on the other bulbs dim because the alternator out put is low at idle. Does it get better when you give it some gas? The rheostat in the headlight switch only controls the dash illumination, not the directional or high beam indicator. Often working the knob clockwise and counter clockwise a few times will clean it up. Concerning the directionals and or fuel gauge, I would clean any grounds and connections at the dash and at the directional out by the running lights and the connections at the fuel tank sender. Good luck
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

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bubba22349
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Re: Goofy lights

Post #4 by bubba22349 » Wed Jul 12, 2017 11:22 am

Cmm24601, sounds like you have a number of different issues going on! X2 for sure do as B RON CO suggested and its the first thing you need to do to insure good electrical performance, so do a good clean up of all your grounds and connections at each end.

Also make sure that the connections like at the fuel tank sender as well as the fuel gauge at the cluster are nice and snug. The constant voltage regulator only is used for powering the dash gauges, it also needs to have clean and snug hook ups, as well as being sure that is mounting point is clean at the back of the dash for a good ground. But since your problem seams to be with only the fuel gauge concentrate on the condistion of the fuel sender unit and gauge connections.

As for the lights going dim besides making sure all the wiring is in good condistion you might consider doing the excellent mod of using a pair of headlite relays (see below link for one example). This provides full battery voltage to the headlites making them nice and bright and taking most all the load off your headlite switch. It's well worth the effort for safety on a car that's driven often.

For the slow flashing of the turn signals look for the flasher units there are probally two on your car one would be for the 4 way emergency flashers the other is for the turn signals by turning them on you should be able to hear which one is controlling the turn signals. Again make sure the it's wiring connections are clean and snug first! If they still don't flash good you might pick up a heavy duty type flasher as is used when towing a trailer and that should take care of the problem.

On your LED lighting you can likely use them for most of the dash lights with these possible exceptions if you have a low oil presure warning light (and it may also still work), but if yours has an alternator charge indicator light (both of these are sometimes know as idiot lights). This alternator one is a special type blub with a bit of resistance built into it so as to start the alternator charging so make sure you are using the correct bulb number in that socket. Good luck :nod:

Example on installing a pair of Headlite Relays on an early Ford Mustang

http://forums.vintage-mustang.com/vinta ... hting.html
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I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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