Current going through the circuit that energizes the flasher device for the blinkers takes away from the current available to go through the circuit that includes the amp gauge. The flasher takes a more current than you might expect, as it is heating a bimetalic strip that makes/breaks the bulb circuit, and heating always consumes lots of power.
The Stars That Blink was created in 1978.
Your gas gauge might not work on a 1978 Ford Fairmont because the cable is broken. Check the cable to ensure it is not broken or kinked. The other possibility here is that you have a bad fuel sending unit.
If you problem is that the gauge shows oil pressure with the engine off, you have a gauge or sending unit failure.
Made in 1978 First three numbers should be one of the following: 213=12 gauge 233=20 gauge 173=28 gauge 183=.410 bore
1963-1978
When Every Day Was the Fourth of July - 1978 TV was released on: USA: 12 March 1978 Norway: 1982 (video premiere)
Encounters of Every Kind was created in 1978.
Every Kinda People was created in 1978.
America 2-Night - 1978 Help Every Little Person - 1.2 was released on: USA: 11 April 1978
America 2-Night - 1978 Help Every Little Person 1-2 was released on: USA: 11 April 1978
Every Girl Should Have One was created in 1978.
Every Which Way but Loose - song - was created in 1978-12.