Hey guys!

I finally picked up that 84! It's sweeeet!

I'll post some pics and info later once I clean it up but in the meantime friends and family want me to take them for a ride and the ugly choke buzzer is going off.

It has a 350 swap and I guess the choke cable is broken... I'll get into figuring out something long term soon but is there a quick way to turn that damn thing off in the meantime?

 

Needs an alternator.

Don't worry about why; it just does.

 

check your blinker fluid to, its there, trust me, it is...

 

Thanks for the good advice guys! I'll be sure to take it for. Blinker fluid check ASAP! While in there I'll have them check my windshield greese too.

 

YES YOU CANT FORGET THAT YOU CAN CRASH AND DIE!

but seriously i have no idea besides just fixing it the right way.. if the cables broke replace cable u can buy an aftermarket one at any parts store usually. lik pepboys and advance auto and autozone. altho im not sure how well it will work, iv never had a carb third gen. all mine were efi.

 

The choke doesn't have a cable in these cars; and even if it did, it couldn't create the buzzing.

It's the alternator.

 

We'll the light on the dash is illuminated and says choke on it, and if I get it it intermittently shut of the sound also stops. I have a choke cable sitting in the back seat the guy gave me.

It sounded like a sime fix but is now sounding more sinister. Does this mean the alternator is shot or ??? The car seems to be holding power fine...

 

It is the alternator.

Choke cable doesn't matter.

The factory, for whatever reason, decided to label the Alternator light "Choke". The relay that feeds 12V from the ignition ckt to the electric choke on the stock carb is tied into that circuit. The choke heater gets 12V only when the key is in "On" and the relay is released (not operated). One side of the relay coil is connected to switched ignition 12V; the other side goes to the diode trio output of the alt. If the alt is not charging, then the relay coil has 12V across it, just like the light. Thus, if the light is on, the relay is also operated, and the choke gets no power. This keeps it from being heated when the key is On but the engine is not running.

The buzzing is caused by 1/3 of the alternator not working. The alt is actually a 3-phase generator, with 6 diodes in a bridge to form its main rectifier. There is also a set of 3 smaller diodes called the "diode trio", which is where the 12V that is fed to the relay coil comes from. If one phase of the alt is not working, then 1/3 of the time, there will not be 12V on that side of the relay coil but instead there will be ground; and this is enough to keep the relay partially activated. The buzzing, which as I'm sure you've noticed is correlated to engine speed, is caused by the relay dropping partway out and then getting re-operated as the alt spins.

The alt is working 2/3 of the time, which is enough to keep the batt charged and to provide the illusion that it is working, but is defective the other 1/3 of the time.

Your problem is the alt. Replace it.

 

Do let us know how this project goes and get some pictures up.

 

Typo

 

Hey guys, thanks for all the detailed info. Especially the poster above.


I'll now replace the alternator. I'm assuming this should be a fairly simple task... I've replaced a few in other newer cars so here's to hoping.


Any recommendations on what to get? I was thinking at least 100 amp.
Is there any special designations for a gen 1 alternator or are they plug and play?

The guy that I bought it from had a sound system hooked up in it so I'm thinking that's what May have killed the alternator, I'm going for 100 amps to support any system I might want to install.

 

A bad relay will buzz sometimes. It's cycling fast. Muffler bearings, blinker fluid, and windshield grease aside, the choke light will come on for a bad alt crazy as it may seem.

 

is this only 82-84 f bodys? i dont think i even have a choke light in my 85 tpi z28??

 

i thought that was a joke lol

 

The choke light is where TPI/TBI cars have the CEL/MIL.

 

ahhh, thanks u seemed to have cleared up another issue i had, remembering which guage bezel is from my car, lol i have 2, im asuming tpi bezels dont even have a choke light spot

 

WTF?

The bezels are no different, its the cluster and IDIOT lights that are different.

Fuel Injected cars have a CHECK ENGINE LIGHT where CARB'D cars have a CHOKE light. Its the same spot.

 

i think u miss understood me, i have 2 guage face bezels, one, at the bottom where MY idiot lights are, has a "choke" light spot, the other one DOES NOT, i was under the impression he had full GUAGES and not IDIOT LIGHTs...
sorry to thread jack no need to be a dick about it

now back to OPs car.

 

thats odd, my 84 has both a check engine light and a choke light

 

My 83 also has both.

Can't recall offhand where the CEL is in the later cars; it's not impossible that it's in the other spot. Wouldn't matter much one way or the other, esp not to the OP's issue.

Only carbed cars AFAIK have the Alt warning light that's labeled "Choke". Not sure what it's labeled in the carb/TPI overlap years.