How to wire up an electric choke

T

TeezySupreme

Master Mechanic
Feb 3, 2011
489
0
where would be the best place to put mi electric choke 12v wire on a 1980 cutlass
 
axisg

axisg

Royal Smart Person
Jul 17, 2007
2,386
113
YYZ
Re: electric choke

You need a switched 12v + so the wiper motor is pretty common. One of the wires off the alternator should be switched as well.
 
T

TeezySupreme

Master Mechanic
Feb 3, 2011
489
0
Re: electric choke

i gotta find out which 1 is the power wire or do u knw which 1 it is
 
joe_padavano

joe_padavano

Royal Smart Person
Sep 13, 2006
1,156
0
Northern VA
Re: electric choke

This question must come up monthly. Simply using a switched power source, especially one that is hot in the ACC position, can cause the choke to open prematurely if the key is on but the engine is not running.

GM used two different methods, depending on the vehicle. Most used an oil pressure switch in the power line to the choke. This way, the choke doesn't start to heat up until the engine is running and there is oil pressure. I ran a fused wire (20 A fuse) from the BATT terminal on the alternator to the switch, and from the switch to the choke. Very simple to wire and very clean. I like to use the Standard P/N PS64 switch. The middle terminal works the OIL light, the other two are a normally open switch that closes with oil pressure. Use these to control the choke. If you have an oil pressure gauge instead of a light, simply use a brass tee fitting to connect both this switch and your oil pressure sender.





The other way is to use a relay that is triggered by the field wire on the alternator (brown #1 wire on SI-family alternators, for example). The field wire is only hot when the alternator is turning. This is how GM wired the stock G-body cars with electric choke when the gauge package was installed. Of course the down side with that is that the choke will close if you break the alternator belt. A typical wiring diagram for the second method is here:



Edit: added schematic for oil pressure switch option
 
T

TeezySupreme

Master Mechanic
Feb 3, 2011
489
0
Re: electric choke

ok i get it i will be gettin my oil pressure switch asap
 
Bonnewagon

Bonnewagon

Geezer
Sep 18, 2009
6,433
113
Queens, NY
Re: electric choke

That is the best explanation I've ever seen for the electric choke!
 
Blake442

Blake442

Geezer
Apr 24, 2007
6,793
113
Minneapolis
Re: electric choke

Joe's right, this question does come up almost monthly.

It's one of those things that really deserves a stickey...
 
  • Agree
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Longroof79

Longroof79

Rocket Powered Basset Hound
Oct 14, 2008
10,344
113
Gainesville, Fl
Re: electric choke

I agree. This definitely should be a sticky.

Very nice write-up, Joe. Well done.
 
  • Agree
Reactions: pontiacgp
dougfather

dougfather

Master Mechanic
Jul 11, 2006
288
16
Altoona PA
Re: electric choke

I just now found this and need to do this for my V8/gauge swap. Sticky it is.

And of course move it to a more deserving forum. "Electrical and Interior".
 
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C

cashmoneyspeed

Greasemonkey
Mar 2, 2009
163
18
Chicago
Re: electric choke

For my electric choke, I tapped into the 12V wire into the pink wire coming off the distributor. Good info with that oil pressure switch, might just have to do mine that way with a tee when i hook up my oil psi gauge.
 

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