Hooking up a Electronic Choke on a weber

[1lo620]

Ok I have a 74 620 with a manual choke weber on it.. But I am putting on a new weber with electronic choke.. Is there a way to wire this up so it works.. And if so, can someone explain it to me.. FYI.. not the best mechanic in the world, but if you explain it I could probly figure it out... I hope...LOL!!!! thanks for the help in advance!!!

[MicroMachinery]

Wire it to a power source that is only hot when the key is in the "ON" position. I wire mine to the coil, because it's close(less wire clutter), and because it only gets juice when the key is on.

[1lo620]

Wire it to a power source that is only hot when the key is in the "ON" position. I wire mine to the coil, because it's close(less wire clutter), and because it only gets juice when the key is on.

 

Do I hook it up to the positive side I am assuming? I know that probly is a dumb question, but I did say i wasnt the best mechanic...LOL!!!!

[datsunaholic]

Of course, you could always use the stock wiring.

 

Unless it's been removed. I don't know how stripped out your engine compartment is. A '74 came with an auto-choke relay from the factory, which was driven by the voltage regulator. There was an electric choke in the truck originally, so the carb's wiring harness included a choke wire. On a '74 I think that wire come out of the firewall harness, but I'm not positive. Mine's been hacked to pieces. If the wires were stripped out then you need to find a new power source, though running it off the coil isn't the best idea it'll work. But if the coil is STOCK on a '74, with the external ballast resistor, you don't want to use that either. You'd need to run it to the high side of the ballast.

[banzai510(hainz)]

look for a loose or open wire that comes from the fire wall.

Turn key on and see if you see the 12volts or so.

That should be the wire.

I usuall lae a jumper wire that plus in to the stock round end and use a red female end that plugs in to the male end on the Weber DGV

[datsunaholic]

Key on won't turn on the choke relay on a '74, actually have to have the alternator charging. So it has to be running. Relay is fed off the voltage regulator.

[1lo620]

:blink: :crying: I will take it my friend that is a mechanic. He has done work for me before...I dont want to screw up any electrical crap in my truck... But thanks for the help!!

Just curious, if I dont hook it up, I will just have to hold the gas pedal to warm it up right?

[banzai510(hainz)]

Dataholic

My 521 has a stock wire and when I turn the key On the wire is then HOT.

But I just assumed(620s) was the same as a 521.

 

 

Just curious, if I dont hook it up, I will just have to hold the gas pedal to warm it up right?

The choke stays on ALLTHE TIME!!!!!!!!!!! when there is NO POWER

putting the POWER/voltage to the choke is really just a heater coil. when it gets HOT it will open the choke plate.thus no more.

choke.

 

one way to pybass this as you mention is looses the 2 or 3 screw and turn the plastic circle till the plates are open up. Then you can just pump the gas till its warm and that will work.

[datsunaholic]

Hainz:

 

Dunno about the 521, never had a running one, and all but the '72 had manual chokes IIRC. 620s have choke relays operated by the voltage regulator, so that when the alternator light is on, the choke heater is off.

 

 

Dave:

 

Hainz is right, you leave it diconnected it'll start fine, but the choke will be closed (or mostly closed, engine room heat will open it a little) AND it'll be stuck in high idle. Back off the choke so it's always open, the at least it;ll be open BUT you'll also have no high idle, and it'll be harder to start especially come October.

[Pacific coast Datsun]

Dave..mines a 74 & im running a elec choke weber. Used the same wire that went to the hirachi. Ill text a pic of it to you today.

[banzai510(hainz)]

Dave..mines a 74 & im running a elec choke weber. Used the same wire that went to the hirachi. Ill text a pic of it to you today.

 

 

thats what I did with my 521 as it had a choke wire. However I never like the auto choke. as it stayed on to long . I turn the plactic circle till the choke plate was open and called it good. I now have a manual Weber on they.

 

there is a conversion cap also if you want to use the manual set up pull cable

 

Doug,

late 521s under the 72 year had electric choke wire.

I dont know if they is a relay or not, never looked

[az_rat210]

Run power off the Ignition relay in your engine compartment or use the ignition relay to run a bosch relay pulling power directly off the battery. The choke only requires 12v constant not alot of amperage, so pulling from the ignition relay would be fine. If you wanted a protected circuit, a Bosch relay with an 1N4001 Diode to prevent feedback and a 10 amp fuse should do fine. Power the relay from the ignition relay (min 7v to activate). Note the diode is to prevent reverse coil discharge.

[Lobo]

does anyone know what color the stock wire was for the choke

[datzenmike]

Usually Blue for choke. Think of being blue with cold. The wire may have a black outer sheath to protect it but blue inside.

 

The idle cut solenoid will be Red

[72MAMBA]

I have a question in the same ballpark if i have a 32 36 manual choke can i just convert my choke into electrical choke without replacing the whole carb.

[ggzilla]

Not unless your 32/36 has the round spot to bolt on an electric choke. If it does, the Datsun choke will bolt on.

 

[72MAMBA]

Yea the carb shop hooked me up with an electric choke . Do i just need to hook up the positive to the choke . How does the electric choke work?

[ggzilla]

For how to connect the choke wire, see Post #2 above.

 

For the theory of how the choke works, see any repair manual.

[boonedock saints]

WARNING......if by chance the + wire you are using does not have a relay or a fuse/breaker of some sort, and say your little heater coil in the electric choke gets too hot, due to other issues....it could cause the wire you ran to the + side to burn/ignite catch fire, and so on.

 

Its not likely, but it can and has happened...just food for thought.

[ggzilla]

To prevent that problem, connect it to the coil ballast resistor hot side. It is fused via the IGN fuse.

[72MAMBA]

So im connecting my choke to my 12v electric fuel pump + that has a fuse. the pump only turns on when the key is turned. so if its only + to it how does it know how to shut off if the key is turned were is the ground?

[ggzilla]

> so if its only + to it how does it know how to shut off if the key is turned

 

It should be connected to a keyed 12v. Most us use the coil wire since that is fused and works with the key

 

 

 

> were is the ground?

 

It grounds the the carburetor body.

[72MAMBA]

Well I took my Carb to alondra carburators and it got rebuilt had issues with it the first time i installed it it it was drivable and i took it to his shop to adjust it only charged me 20 adn he hooked me up ,my 620 is rolling great cant complain .