sorch60

So, the choke light on my 87 Camaro LG4 is on and I got a bunch of responses last time about the alternator being bad. Well, it's charging fine and seems fine to me. My question is that if the belt was too tight as I have a habit of making them would it kill allow the alternator to keep charging but cause other alternator problems making this light go on? Or, is it something else all together.

Someone HELP!!

Vader

I understand. If I've read one post about how the alternator is the only cause, I must have read 50 such posts. There are othr componencts and circuits involved as well. Oddly, the CHOKE lamp can operate if there is an actual problem with teh electric choke heater element or choke relay/circuit. Wierd, isn't it? That completely ruins my theory of the fuel pump being the problem when the OIL warning lamp turns on...

Check these parts:

RB83L69

Study the circuit, and understand what the "Choke" light needs in order to light.... namely a low resistance path to 12V on one side, and a low resistance path to ground on the other.

Thanks for posting that factory shop manual drawing Vader, I'm too lazy to scan mine.

Here's how the circuit works:

With the key "Off", nothing happens at all (duh).

With the key "On" but the alt not charging (normally this would be caused by the engine not running), 12V is fed from the Choke Heater / Fan fuse to the Choke Heater Realy; the other side of the relay is connected to the alt via the brown wire #25, which is grounded by the regulator inside the alt. The relay operates, and when the relay is operated, the Choke light gets fed 12V to one side of itself through the gauges fuse, and gets grounded on the other side by the choke heater element which is a very low resistance compared to the bulb, so the bulb lights. Not enough power goes to the choke heater to heat it significantly, so the choke itself stays on (the heater doesn't heat and pull it off).

With the key on and the alt charging (obviously this can only happen with the engine running) there will be 12V, generated by the alt and rectified by the diode trio, present on the brown wire #25. When that happens, there is 12V supplied to both ends of the relay, so it drops out (no current will flow from one point to another when they're both at the same potential). So, when the relay drops out, 12V is supplied from the CH / Fan fuse through the relay through wire #78 to the choke heater; and it also reaches the Choke bulb, which has 12V also on the other side, so current ceases to flow through it and it goes dark.

So: things that can cause the light to light while the alt is working, include the relay; the Gauges fuse being blown; wiring hacked; and not a whole lot else. The choke heater itself cannot cause it unless it or its wire is shorted straight to ground, but the circuit around it can.