Choke light on automatic transmission?

[My78truck]

I Have a 1978, 350, V8, automatic TH400 transmission in my truck. When putting my cluster back together, next to the 4-wheel lock light space (which I do not have) is a "choke" idiot light. I replaced the PCB and used the old one to place the clips/light bulbs where they need to be. My old PCB had a lightbulb located at the "choke" idiot light place. I cannot remember if it lit up or not. Would an automatic transmission have a choke function? Is it supposed to light just when starting? and then go out? If so, any ideas on why it is not lighting now?

Thanks, again, and again, and again.

 

[CorvairGeek]

The choke light is operated by an oil pressure switch. The purpose is to verify the electric choke heater is plugged in. It is supposed to function as follow;

Key on before starting - Choke light illuminates because of no oil pressure

Key on, engine started - Choke light goes off as soon as there is oil pressure. If it does not, it indicates the choke heater wiring is damaged or unplugged, or the choke heater is burned out.

Choke lights were used regardless of transmission.

 

[Bextreme04]

The choke light is operated by an oil pressure switch. The purpose is to verify the electric choke heater is plugged in. It is supposed to function as follow;

Key on before starting - Choke light illuminates because of no oil pressure

Key on, engine started - Choke light goes off as soon as there is oil pressure. If it does not, it indicates the choke heater wiring is damaged or unplugged, or the choke heater is burned out.

Choke lights were used regardless of transmission.

IN A 78? A 78 shouldn’t have an electric choke from the factory, right? My 80 has a hot air choke and my 74 had the divorced thermostat spring.

 

[Turbo4whl]

IN A 78? A 78 shouldn’t have an electric choke from the factory, right? My 80 has a hot air choke and my 74 had the divorced thermostat spring.

Most likely the gauge set has been swapped for a later year. 1978 would still have a 100 MPH speedo?

 

[Swearbody]

Ha. when I did the engine swap in mine I discovered the choke light. It didnt work before then, or on any of my previous trucks. I went to turn the key the first time after reinstalling the engine and blam...choke light. I must have "fixed" it somehow during the engine bay prep or install.

 

[CorvairGeek]

IN A 78? A 78 shouldn’t have an electric choke from the factory, right? My 80 has a hot air choke and my 74 had the divorced thermostat spring.

That's a good question. My '78 292 L6 has an electric choke and so did my '78 305 2bbl.

My '78 C20 has a 100MPH speedometer.

 

[My78truck]

This truck has a 100 mph speedometer. The oil pressure gauge was switched but registers oil pressure. This IS a 1978 built in the early part of 1978. This truck is part SAE and part metric, it has some things that go back to 77 and some that go into 79. So, it may, or may not, have an electric choke. Have to get that figured out by a mechanic.

 

[dsteelejr]

Most likely the gauge set has been swapped for a later year. 1978 would still have a 100 MPH speedo?

I believe my '80 came from the factory with a hot air choke and it has the yellow lens for the choke light in the speedo, but it wasn't used. It's a base model GMC Sierra and had all idiot lights and no small gauges. On the speedo, half of the yellow lens was Four Wheel Drive and the other half was Choke. On the fuel gauge one half of the red lens was Fasten Seat Belts and the other half was Brake. The cluster didn't have a provision for a bulb for the Choke light or the red Brake light since it was a hot air choke and it was using the big red brake light in the lower left where the gauges are. I'm guessing it was a universal lens. They probably used that same lens in two wheel drive models too.

 

[dsteelejr]

I Have a 1978, 350, V8, automatic TH400 transmission in my truck. When putting my cluster back together, next to the 4-wheel lock light space (which I do not have) is a "choke" idiot light. I replaced the PCB and used the old one to place the clips/light bulbs where they need to be. My old PCB had a lightbulb located at the "choke" idiot light place. I cannot remember if it lit up or not. Would an automatic transmission have a choke function? Is it supposed to light just when starting? and then go out? If so, any ideas on why it is not lighting now?

Thanks, again, and again, and again.

Light bulb could've come loose or have bad contacts. The BRAKE light in my '73 C20 is supposed to light up at start up to let you know the light works. Sometimes it doesn't light up. Many years ago I found the bulb was burned out. Put a fresh one in thats still good, but I think its a little loose in the socket and sometimes doesn't make contact.