Choke light and fast idle staying on

Howdy. I have an 86 Chev 1 ton, 454 and auto. And of course I have a problem and a case of the stupids today.

The choke light and fast idle are staying on all the time. I figured a short in the choke wiring and haven't found anything.

And someone also took the screws out of the choke housing and replaced them with stinkin rivits.

Where should I start looking ? This time of year I can force the choke open and change the fast idle to get by but this problem is starting to irritate me.

Have pity on me, I'm a nerd by trade and half-assed shade tree mechanic but I've never really had to do much to this truck in the 10 years I've had it.

Randy snipped-for-privacy@MeinerSolutions.com

Reply to
rjmacres
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Choke heater fuse, oil pressure switch.

Power comes into the fuse block, passes thru the choke heater fuse, goes to the oil pressure switch which is a NO switch until oil pressure sends it closed, power then goes to the choke heater. There is another wire on the cold side of the oil pressure switch that goes to one side of the choke warning light, the other side of the warning light is fed power on the ignition feed that feeds the entire instrument cluster, when everything is working as it should, there is 12 volts on both sides of the choke warning light and it does not light, when power is lost via the oil pressure switch, 12 volts from the choke warning light finds a path to ground thru the choke heater and the warning light illuminates.

Reply to
aarcuda69062

Thanks for the info. That sure sounds like a real convoluted setup.

Randy

Reply to
rjmacres

It's quite basic actually. A fuse to protect the circuit, a switch to make sure that the choke only heats when the engine is running and a warning circuit which operates basically the same way GM alternator warning lights have since day one.

You had also mentioned rivets holding the choke stat on... The rivets are how the factory built it, reason being was to make the choke stat somewhat tamper proof.

Reply to
aarcuda69062

Fuse was blown. I put a new and my last 20amp fuse in, started it up and pop, new fuse blew. Guess I'm back to looking for a short right ? Or could something else be causing it to blow ?

Randy

Reply to
rjmacres

I'm used to working on old VW's and just older cars in general. On those when a fuse blows it cuts the juice to that circuit. On this Chev, the fuse blows and the choke light comes on. Backwards to me but I'm known for being easily confused.

Randy

Reply to
rjmacres

Yup.

if it popped right quick, it's probably a short to ground somewhere.

Reply to
aarcuda69062

e quoted text -

I called it a day after I had a temper tantrum still trying to find tools. Will pick up a new multimeter, test light and a bunch of fuses tommorow when we go to town for supplies.

And yep, it popped real quick, not even sure I had done much more then turn the key but will retest when I get some fuses.

I sure hope the mice didn't get into it. They've caused us lots of damage and headaches this past year.

Randy

Reply to
rjmacres

quoted text -

Go buy a short finder. They are basically nothing more than a modified compass and a circuit breaker with clips on the leads. The breaker open/closes the circuit and you follow the wire with the meter. When you get to the short the needle stops moving. Another item that works pretty well is to use a low voltage detector and a circuit breaker. In that system you follow the wire with the voltage detector and watch for the light to go out.

Reply to
Steve W.

Now that sounds like a plan. What kind of store would I find one of those in ? We live out the boonies and the nearest town is real small and not many options for hardware or automotive.

Randy

Reply to
rjmacres

Or clip a large 12 volt bulb, like a tail/stop across the fuse and start looking. When you find the short the light will go out. A short finder is available at Harbor Freight. It's just a circuit breaker and a magnetic ammeter.

Al

Reply to
Big Al

I keep a 12v bulb/wire/alligator clip setup around all the time. Good for all sorts of things but my main use for it is static timing VW motors. Bad thing is right now I can't find it. Between moving, new shop not being completely done and my wife cleaning the little shop, I'm screwed and can't find much of anything.

I did swing by the local autoparts store and pick up some stuff to help track the short down. Just need to find some time to get back to it.

Randy

Reply to
rjmacres

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