electric choke question

[toolmanmike]

Here's a fun little controller from Holley. Looks like it controls the ground depending on engine temp. Never seen it before. I would imagine when it senses higher engine temperature it would cut back the current to almost nothing.
Holley 45-267 Choke Delay Kit

 

[halifaxhops]

How would you control the ground? Its the carb.

 

[RedFish]

How would you control the ground? Its the carb.

Maybe for some but not all. Looks like Holley electric choke has 2 wires.

 

[toolmanmike]

How would you control the ground? Its the carb.

My Edelbrock has a external ground as well.

 

[halifaxhops]

I have to look at mine been a while. A thermal switch is a great idea that has to draw a few amps.

 

[toolmanmike]

How would you control the ground? Its the carb.

I am looking but haven't found one so far. Do you know if the slant 6 controllers are still available and do they shut the current off when the choke is open? They may work like the one I linked in post#21. I guess as long as it cuts back the current to almost nothing it would be as good as shutting it off.

 

[toolmanmike]

I have to look at mine been a while. A thermal switch is a great idea that has to draw a few amps.

Tom said his draws just a tick over 5 amps.

 

[halifaxhops]

I believe it it is a heating element.

 

[RedFish]

So a controller is available to lower current draw after choke is heated. That might extend the life of the element. My initial comment/question here was about current available at cold start. Even with the ballast resistor in line, brown wire supplying the coil in start, there is no diode at ballast resistor. Current is reduced as it travels opposite direction through resistor, into the blue wire and on to ignition module, charging system, and the electric choke. Without ballast resistor, blue and brown tied together, the draw through blue wire during start isn't reduced.
Please keep in mind that I don't have electric choke or any problems. Just pondering the problems a couple of members are dealing with recently.

 

[toolmanmike]

So a controller is available to lower current draw after choke is heated. That might extend the life of the element. My initial comment/question here was about current available at cold start. Even with the ballast resistor in line, brown wire supplying the coil in start, there is no diode at ballast resistor. Current is reduced as it travels opposite direction through resistor, into the blue wire and on to ignition module, charging system, and the electric choke. Without ballast resistor, blue and brown tied together, the draw through blue wire during start isn't reduced.
Please keep in mind that I don't have electric choke or any problems. Just pondering the problems a couple of members are dealing with recently.

The Holley controller would work well. It should reduce the current draw as the engine warms up. Halifaxhops found some thermal switches that would shut the current off at a set temp. Those might work as well. 5Pcs Temperature Switch Control Sensor Thermal Thermostat 35-160 Degrees KSD301 | eBay

 

[RichB]

The correct setting for the choke when cold is a credit card thickness opening.

 

[Dave NEO]

So I started up and could tell it was making a positive difference - it wanted to stay idling while still cold without quitting and having me restart numerous times. I think it could benefit from a little higher idle though. I think I read somewhere there was vacuum involved with the choke that boosts idle. Is this connection visible/obvious on the choke housing? I need to learn something about that. I can ask Summit if electric choke on this carb shuts off after warm-up..

 

[Dave NEO]

- e-mailed them a ques. on choke shut of/f amps/etc,
- this was in my carb's instructions

ELECTRIC CHOKE MODELS:
A. Connect the electric choke lead (supplied) to the positive terminal of the choke cap. The other end must be connected to a good fused ignition activated 12-volt source. Hookup of this wire is not optional. (Figure 2)
WARNING: Connecting the choke cap to the ignition or ignition coil could result in unacceptable choke operation, poor fuel economy, and possible engine misfiring, since the voltage delivered to the spark plugs will be severely reduced by the drain imposed by the choke cap. Suitable ignition activated 12-volt sources are most electrical relays, as well as the leads to accessories, such as windshield wipers. DO NOT connect this wire to the original equipment (O.E.) electric choke source. This may not be a 12V source.
B. Check the voltage source with a volt-ohm meter to assure proper voltage and choke operation. Provision of a good ground.

 

[RedFish]

If the factories blue wire, or blue and brown wires tied together, simply signals/closes a relay, ample voltage can be supplied to everything in the engine bay through that relay from a better source. To splice 12 volt supply in at bulkhead side of the fusible link keeps everything at the firewall area. Of course one could buy more wire to route their supply to relay from stud on starter relay. Then some grade of fuse protection in this added wire would be required.

 

[Dave NEO]

Answer I got was : "The choke coil will continue to hold the 12 volt signal. If not the choke would close. There is no listing for the amp draw for the choke coil. "
Well.. I disagree with the choke closing part...- engine heat or just outdoor temp obviously keeps choke open if 12V were gone. (How the heck have I been driving it for several years w/ electric choke disconnected). whatever..

 

[dibbons]

Asking a technical question this day in age (outside the forum) you are more likely to get a wrong answer than an honest "I don't know" answer.

 

[Dave NEO]

just read on a hot rod forum: " I just tested the current draw on an electric choke I had sitting around. For the first 1/4 second, it spiked at 6.5 amps and dropped to 1.3 amps. After that, as the coil heats up, it steadily dropped from 1.3 and leveled out at about .75 amps."

If we could measure the resistance of the choke coil in ohms we could come up with the amp draw..no?

 

[Mattax]

just read on a hot rod forum: " I just tested the current draw on an electric choke I had sitting around. For the first 1/4 second, it spiked at 6.5 amps and dropped to 1.3 amps. After that, as the coil heats up, it steadily dropped from 1.3 and leveled out at about .75 amps."

If we could measure the resistance of the choke coil in ohms we could come up with the amp draw..no?

Yes. You could then calculate the current draw based on supply voltage.
The Hotrod test you quoted indicates that particular choke assist changes resistance with temperature.

 

[Dave NEO]

Holley says 7.5A with particular 4bbl I asked about as an example - people with various carbs seem to report all kinds of numbers from 1.0 up to 7A. So a circuit with at least a 10 amp fuse seems like good idea. I ended up moving mine over to the wiper motor plug for a cleaner, shorter run. Adjusted choke to slow up a bit and now it's about 90 seconds to full open. NOW.... if I can find a 1/4" open end wrench that's about 8" long so I can reach fast idle speed screw under the choke housing (or tiny hands of extraordinarily dexterous 5 yr. old...). Must be a trick to get at it short of removing carb..thanks all for comments in this thread.

 

[4spdragtop]

Start with a 1A fuse and work your way up?

 

[toolmanmike]

I don't think I have a small diameter wire inductive amp pick up for testing. If someone does that would be good. If it spikes around 10 and settles to a few amps draw towards the end of the warm up that should be fine if hooked to the positive side of the ballast resistor. That's really what this whole conversation is about. If it pulls 10 a. continuously and shares it's power with the ignition, that's not a good thing.

 

[Dave NEO]

Service manual says all wiper motor has is 6A breaker at switch. Is this going to get interesting if I ever run wipers. 'Spose I could do another relay - just pulling enough power from the wiper motor plug to open relay and get 12V direct from battery to the choke.

 

[toolmanmike]

Service manual says all wiper motor has is 6A breaker at switch. Is this going to get interesting if I ever run wipers. 'Spose I could do another relay - just pulling enough power from the wiper motor plug to open relay and get 12V direct from battery to the choke.

With a fuse.

 

[Dave NEO]

roger that.

 

[Dave NEO]

installed relay, used splice into wiper motor plug. Works good - one flooring of the accelerator, turn key, runs a lot better on it's own. Headlights and choke - that's it for relays/add-ons in engine bay. 15A fuses.