Okay the choke light came on in my 80 and it won't go off. I have replaced the choke thermostat, the relay and the oil sending unit because I think it is also involved in that peticular circuit.
Anything else I need to check? I know I could pull the bulb but it really drives me crazy when something isn't working propoerly on my car. And yes the choke functions perfectly.

Kona

 

TTT Anybody even have a wild a$$ guess?

Kona

 

Kona ,the light on means a loss of power to the choke heater. check the fuse and check if you have 12 volts to the choke ,,also check the choke relay in the console..if you need the wiring diagram email me at prissyo@aol.com..MIKE

 

Okay heres the weird thing. I just verified that the choke thermostat is getting power and if it is getting power you would think the relay is working properly right? Oh yeah and forgot to mention I did replace the relay.
Starting to sound like a short.

Kona

 

Check the choke heater fuse. The choke will have power even if the fuse is blown, getting back-fed thru the gauge fuse via the illumination lamp.

 

I will check it out tonight. I had no idea that this could be the case.
Guess I should have started with the simplest of fixes hope you are right.

Hook Em Horns!!! Did you go on Sunday?
Kona

 

If the choke on the '80 is like the choke on the '81, it gets power from 2 different circuits. Just because you have 12Volts at the choke doesn't mean it's working right. When my choke light stayed on it ended up being the choke heater relay (located in the center console near the ashtray). If this is the relay you say that you say you replaced then you probably have a bad fuse or a wiring problem.

 

Your kidding, right?...Damn place was crazy...but would have been
Hook-Em Horns!

 

The choke light on my 1980 stayed on when the alternator failed. Replacing the alternator solved the problem. May want to check the voltage output of your alternator.

 

The other one is the alternator (as mentioned above), so check it's output. What I found on my '81 was that the 2 sources can be fine but the light still stays on. With mine it was due to a broken track in the pcb behind the gauges. It's a pita to get it out but, if it is the problem, you can use a soldering iron to jump the break with a small wire, saving a fair amount of cash. Getting it all back together so that all the gauges, lights, etc still all work is another matter If you do have to take the pcb out then I found cleaning the tracks where the connector plugs in solves a lot of potential problems (just give them a light rub with some 1200 grade wet-or-dry).
Good luck with it.

 

Guess thats the next step I checked the fuses and everything Ok and the alternator is new and I pulled it and had it checked last night. It's amazing how such a small problem turns into so much work.
Paul just read an article about your MoT? inspections. Sounds like a real mightmare to go through one. Is it as bad as they made it out to be?

Kona

 

Hi Kona, in a word...... "yes" The rules & regs are getting tightened every year (or so it seems). I was convinced (being a cynic when it comes to politicians) that they're doing their best to get old vehicles off of the roads. This was confirmed over Xmas when I read that some members of "Nu Labour" wanted to ban all cars over 15 years old (which would include everything I own!!!). The idea didn't last long, but the fact some of our rulers feel that way is scary. Last year the Vette only scraped through by the skin of it's teeth due to the handbrake (emergency brake). It's no good saying that they are all poor, they have to meet the figures. The tester gave me 3 attempts to hit the figure on his little "swingometer" (should have failed me on the 1st attempt), The 2nd attempt was just under the pass value, so on the 3rd attempt, not wanting to fail, I let go of the steering wheel & grabbed the lever with both hands & pulled as hard as I could. It passed (just) but there was a problem.... the handbrake was almost vertical & I couldn't release it. We were stranded at the roadside for a few mins while we were both trying to release it. It ended up with me squatting on the floor & heaving up on it with both hands, while he was hitting the release button with the palm of his hand (I think he liked Corvettes up until then). I might find somewhere else to get the test done next year, he's bound to remember me.... An MOT used to be just a pita as it meant wasting a morning/afternoon to get one done. But now, even if the vehicle seems to be in good condition, there's always some odd rule that can catch you out (my bike recently failed because the height of the digits on the licence plate were a few mm undersize - I still can't work out how that affects safety? ).

Before pulling the gauge cluster apart see if you can get a wiring diagram & check for continuity, otherwise you could be wasting your time. From memory (which is far from reliable) I think the light works by having +12v on each side of it. One comes from the alternator & the other is the supply to the choke coil. With the engine is started from cold there will be power flowing through the choke coil & also through the bulb as the alternator is pushing power through it. As the coil heats up the current flow stops (or reduces dramatically) due to the increased resistance, so there is +12v on each side of the bulb so no current flows through it & it goes out. If current can flow either way through it (due to a cold choke coil or a failed alternator) then it will come on. Or, it's something like that. It's not the normal +12v on one side & ground on the other. Or something like that! I remember checking all the circuits as far as I could on both the choke & alternator side on mine & finally pulling the gauge cluster as a last resort. Finding the broken track needed an AVO (as it was a hairline crack) and fixing it was simple, but be careful not to bend the pcb more than you have to as there's a danger of breaking some of the other old & brittle tracks (as they say, don't ask how I know this ).
Good luck with it