Electric Choke Disconnected?

[83kid]

Hi,
So i recently bought an 83 k10, with a 350 5.7
The guy said he had the carb tuned up recently, and while doing so the person doing the tune-up disconnected the electric choke for the summertime (Northeast U.S., cold winters but in the summer gets pretty hot)

So, im wondering how i would re-connect the electric choke, how would you assume that it was disconnected?

Also, is it fine to leave the choke connected during the summertime when the weather is warmer, and some days you dont even need the choke? Doesn't hurt the engine?


Thanks!

 

[Boone83K10]

he probably disconnected it because he couldn't get it to work properly. electric chokes can be wired and connected at all times, no need to disconnect.

you didn't mention what kind of carb you have. most chokes are on the passenger side of the carb. you will be looking for a wire going to the side of the choke housing, it should only receive 12 volts when you turn the key on. the wire (if disconnected) could be laying on the intake manifold or the valve cover. it will be a single wire.


now, I imagine he disconnected it because it's wired wrong or something. find the wire and hook it up and report back.

 

[83kid]

Not certain on the carb, previous owner replaced it when he rebuilt the engine and i don't know how to tell what it is.
Theres a wire with a female connector going to the electric choke (which is on the passenger side), and one next to it with the female connector facing the reverse way, which goes around behind the choke, clueless as to where though.

So the wires hooked up to the choke all fine, traced it back a bit and it goes directly underneath the cab somewhere, i was expecting it to go to the dash, although i don't know where it should be.

I'll check it with a multimeter if i get the chance, would have to borrow one, or need to buy one.

 

[Boone83K10]

Pics of wires and carb

 

[83kid]

Edelbrock carb, forgot to mention that, meant i have no clue about anything besides the brand.

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[Boone83K10]

Wire closest to front of truck is the ground wire, that looks good. Write going towards firewall is the hot wire. You need to test that wire for 12V when key is on. If it has power while off then you need to find a different 12v source. You need to trace where it goes now.

 

[83kid]

Ok, from what i recall it disappears directly under the cab, going back being my exhaust and transmission, i can't really see where it goes, maybe it wraps back around or something.

Anyone know where that wire usually connects to in most trucks, so i can go there and check it too?

Also, my choke light is on in the dash. Does this mean its on or its not connected, or anything like that?


Thanks!

 

[chengny]

The choke heater receives it's power via the engine oil pressure switch - not the sender.

The sender is shaped like a bell and drives the oil pressure gauge on the dash - it has only one wire connected to it. The connector looks like a rubber boot.

The pressure switch has what appears to be 3 wires connected to it. Because of a splice in the connector, there are actually only 2. The connector is a snap around type.

The pressure switch is normally open and closes when oil system pressure reaches about 10 psi. When the contacts close, power (just normal 12 VDC) is supplied to the heating element within the choke pull. This allows the choke to begin opening as soon as possible. The lead to the choke heater is the light blue one in the pictures below.

Some images to help explain:

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WARNING - The same switch that controls power to the choke heater also shunts power away from the CHOKE light on the dash. If you have a CHOKE light on your dash display, it should go out immediately upon engine start and stay out as long as the engine is running. If the CHOKE light illuminates with the engine running; treat it as a LOW OIL PRESSURE warning. Shut down.

 

[Boone83K10]

Being that it's an aftermarket carb, people hook them up to whatever they can find. Your choke light was used in stock form, it would go off when the oil pressure switch received oil pressure. It may be disconnected at that point or you have low oil pressure. You should get your hands dirty and actually trace that wire for the choke. I doubt it goes down below the cab, there is nothing down there that is a 12v source. It probably comes back up near the brake booster and goes inside of cab. The previous owner of my truck used the wiper motor wiring for 12v source to the coke.

 

[83kid]

Well, i can't find to where the wire does go. 2 person job last time when i was looking, have to tug a wire and have someone looking somewhere else, but i'm alone looking today.
With the oil pressure switch part of it, my oil pressure gauge is mechanical i believe, has a plastic tube with oil that flows through it. Would this still have the switch, or would it be different?

And, thanks for the warning about possible low oil pressure. I always check my gauge, which is usually at 50 cold, 40 idle hot, and upwards of both of those when i accelerate hard, so i believe that its fine, and ill notice if it isn't.

 

[Boone83K10]

If you're running a mechanical gauge then someone has removed the electrical and your choke light will remain on. Just verify you are only getting 12v when key is on for choke, if not then trace it.

 

[chengny]

Until you get a good look behind the distributor and see what was done - it's all speculation at this point.

Remember, there are 2 devices that sense engine oil pressure:

1. The oil pressure switch, which is either open or closed (closes at 10 psi rising) and controls choke heater/CHOKE light.

2. The oil pressure sender. Basically a variable resistor which reacts to oil pressure (range is about 0 - 60 psi) and controls the stock oil pressure gauge on the dash.

Whoever ran the sensing line for your mechanical gauge probably pulled the sender (as opposed to the switch) - and used that port to tap into the oil system. At least that's what he should have done.

Doing it that way would have allowed the choke heater to be energized as normal (i.e. through the pressure switch when oil pressure is established). Here are some annotated images showing the basics of the two different systems - and the sensing line to your mechanical gauge:

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The images above show the normal configuration of the switch/sender in later models - both behind the distributor. However, earlier 350's were different. One of them was tapped into the oil system way down on the LH side in the far back. It screwed in to the block just above the oil filter:

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I am fairly certain that the sender was the one down there but it might have been the switch. Anyway, my point is: that may be where the hot wire to the choke heater (the one you are having trouble tracing) originates.

 

[HotRodPC]

Chengny beat me to it about the Oil Pressure switch and the choke wire being hot with the key in the on position. That's if it your wanting to keep the OEM factory choke wire set up.


You could if you wanted to, just run an ignition hot wire directly to the choke too. But then of course you're bypassing the low pressure high idle choke protection.

 

[hinkv10]

+1 on what Hotrod said about running a wire. This is about as easy of a job as you will find on a square. I didn't see anybody mention it but you probably have an Edelbrock 1406 carb. I have a similar truck and a year and a half ago I bought the truck with electric choke not working. Its a one person job to fix but you need a test light.

1. Check the ground wire of the choke by connecting to positive terminal on battery and verifying that you have ground. If not either replace wire or clean contacts, should probably be done either way as it takes but a minute.

2. Connect test light to good ground and check for power at power side of choke. Shouldn't have power when off and then try with key on and then while running. My power wire was hot but not connected because the electric choke was dead, seriously corroded internally. The wire went thru the firewall and was plugged into the fuse box. I replaced it as its only $2 worth of wire. I ordered a replacement Edelbrock electric choke kit Amazon but you can also get it from Summit etc. I think it was 30 or $40 bucks. Hooked it up and it worked mint

I then sold the Carb and installed a SMI rebuilt Quadrajet and it got me a little extra mpg but it ran fine with the Edelbrock.