Power for Electric Choke
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On the heater fan it has a yellow wire which supplies low speed power to the
fan. I didn't like the fan to run all the time and had previously
disconnected this wire. When I put the electric choke on I used this wire. I
haven't checked if that wire goes dead when the speed on the fan is increased
so I just let it warm up before I turn the fan on a higher speed. It has
worked well thus far. Darren
> Those of you who have changed over to electric chokes, where did you pull
> power from for the choke? I'm thinking of either the HEI input or the
> alternator output. Any other options?
>
> Patrick
- --
Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com
fan. I didn't like the fan to run all the time and had previously
disconnected this wire. When I put the electric choke on I used this wire. I
haven't checked if that wire goes dead when the speed on the fan is increased
so I just let it warm up before I turn the fan on a higher speed. It has
worked well thus far. Darren
> Those of you who have changed over to electric chokes, where did you pull
> power from for the choke? I'm thinking of either the HEI input or the
> alternator output. Any other options?
>
> Patrick
- --
Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com
Patrick:
When I installed mine from NAPA, it took two power sources. One
switched and one unswitched. For the switched source, I used the blue
distributor wire; for the unswitched I used the heavy white wire to the
alternator. Sounds like you're on the right track.
Ray Elliott
When I installed mine from NAPA, it took two power sources. One
switched and one unswitched. For the switched source, I used the blue
distributor wire; for the unswitched I used the heavy white wire to the
alternator. Sounds like you're on the right track.
Ray Elliott
Hi, Patrick,
The alternator output is an excellent source because if the engine should
die before it has warmed up, the power will be removed from the choke. This
will enable you to start again easier and idle better until the engine is
warm.
Cars that are original with electric chokes use a switch on the oil pressure
sender to accomplish the same thing.
Another place you could use that would work as well is the R output of the
alternator...or is it the I output? Sorry, CRS attack. In any event, it's
the black wire, not the red battery sense wire, that is in the two-conductor
plug on the alternator. This line goes high when the alternator is charging
i.e. when the engine is running but goes low when the alternator isn't
charging, as when the engine dies. Diesel GM pickups used this wire for the
glow plug timer heaters, the diesel equivalent to an electric choke...
Travis
> Those of you who have changed over to electric chokes, where did you pull
> power from for the choke? I'm thinking of either the HEI input or the
> alternator output. Any other options?
>
> Patrick
The alternator output is an excellent source because if the engine should
die before it has warmed up, the power will be removed from the choke. This
will enable you to start again easier and idle better until the engine is
warm.
Cars that are original with electric chokes use a switch on the oil pressure
sender to accomplish the same thing.
Another place you could use that would work as well is the R output of the
alternator...or is it the I output? Sorry, CRS attack. In any event, it's
the black wire, not the red battery sense wire, that is in the two-conductor
plug on the alternator. This line goes high when the alternator is charging
i.e. when the engine is running but goes low when the alternator isn't
charging, as when the engine dies. Diesel GM pickups used this wire for the
glow plug timer heaters, the diesel equivalent to an electric choke...
Travis
> Those of you who have changed over to electric chokes, where did you pull
> power from for the choke? I'm thinking of either the HEI input or the
> alternator output. Any other options?
>
> Patrick
>Those of you who have changed over to electric chokes, where did you pull
>power from for the choke? I'm thinking of either the HEI input or the
>alternator output. Any other options?
>Patrick
We have the coil ign, ( 73) so I used the + coil input voltage as the
supply for the choke. a switched BATT lead off the ignition switch is an
option. ( voltage on when engine on, voltage off when engine off)
John Szalay
73 GMC "WBY"
>power from for the choke? I'm thinking of either the HEI input or the
>alternator output. Any other options?
>Patrick
We have the coil ign, ( 73) so I used the + coil input voltage as the
supply for the choke. a switched BATT lead off the ignition switch is an
option. ( voltage on when engine on, voltage off when engine off)
John Szalay
73 GMC "WBY"
>
> The alternator output is an excellent source because if the engine should
> die before it has warmed up, the power will be removed from the choke. This
> will enable you to start again easier and idle better until the engine is
> warm.
That was my thinking.
> Another place you could use that would work as well is the R output of the
> alternator...or is it the I output? Sorry, CRS attack. In any event, it's
> the black wire, not the red battery sense wire, that is in the two-conductor
> plug on the alternator. This line goes high when the alternator is charging
> i.e. when the engine is running but goes low when the alternator isn't
> charging, as when the engine dies. Diesel GM pickups used this wire for the
> glow plug timer heaters, the diesel equivalent to an electric choke...
Actually, I was thinking of tapping onto the center isolater terminal.
Should only be hot when the alternator is charging.
Patrick
- --
Patrick Flowers
Mailto
atrick
The GMC Motorhome Page
http://www.gmcmotorhome.com
> The alternator output is an excellent source because if the engine should
> die before it has warmed up, the power will be removed from the choke. This
> will enable you to start again easier and idle better until the engine is
> warm.
That was my thinking.
> Another place you could use that would work as well is the R output of the
> alternator...or is it the I output? Sorry, CRS attack. In any event, it's
> the black wire, not the red battery sense wire, that is in the two-conductor
> plug on the alternator. This line goes high when the alternator is charging
> i.e. when the engine is running but goes low when the alternator isn't
> charging, as when the engine dies. Diesel GM pickups used this wire for the
> glow plug timer heaters, the diesel equivalent to an electric choke...
Actually, I was thinking of tapping onto the center isolater terminal.
Should only be hot when the alternator is charging.
Patrick
- --
Patrick Flowers
Mailto
atrickThe GMC Motorhome Page
http://www.gmcmotorhome.com
>
> We have the coil ign, ( 73) so I used the + coil input voltage as the
> supply for the choke. a switched BATT lead off the ignition switch is an
> option. ( voltage on when engine on, voltage off when engine off)
> John Szalay
> 73 GMC "WBY"
Since I've changed to HEI, it doesn't apply to my coach, but isn't the
coil + terminal 6 volts except when cranking?
Patrick
- --
Patrick Flowers
Mailtoatrick
The GMC Motorhome Page
http://www.gmcmotorhome.com
> We have the coil ign, ( 73) so I used the + coil input voltage as the
> supply for the choke. a switched BATT lead off the ignition switch is an
> option. ( voltage on when engine on, voltage off when engine off)
> John Szalay
> 73 GMC "WBY"
Since I've changed to HEI, it doesn't apply to my coach, but isn't the
coil + terminal 6 volts except when cranking?
Patrick
- --
Patrick Flowers
Mailto
atrickThe GMC Motorhome Page
http://www.gmcmotorhome.com
Interesting. My instructions(Holley) only mention one power source.
Patrick
>
> Patrick:
> When I installed mine from NAPA, it took two power sources. One
> switched and one unswitched. For the switched source, I used the blue
> distributor wire; for the unswitched I used the heavy white wire to the
> alternator. Sounds like you're on the right track.
> Ray Elliott
- --
Patrick Flowers
Mailtoatrick
The GMC Motorhome Page
http://www.gmcmotorhome.com
Patrick
>
> Patrick:
> When I installed mine from NAPA, it took two power sources. One
> switched and one unswitched. For the switched source, I used the blue
> distributor wire; for the unswitched I used the heavy white wire to the
> alternator. Sounds like you're on the right track.
> Ray Elliott
- --
Patrick Flowers
Mailto
atrickThe GMC Motorhome Page
http://www.gmcmotorhome.com
> We have the coil ign, ( 73) so I used the + coil input voltage as the
> supply for the choke. a switched BATT lead off the ignition switch is an
> option. ( voltage on when engine on, voltage off when engine off)
> John Szalay
> 73 GMC "WBY"
John, there's a little potential problem with this: the + coil lead on the
old Kettering (points) type system is downstream of a ballast resistor (it's
resistor wire in the wiring harness on your coach.) Thus putting the
electric choke in with the ignition coil pulls down the voltage available to
the coil by a fair amount. Apparently not enough to cause you problems when
everything is normal, but I would expect you to experience misfiring from a
low battery sooner than you would if you took this voltage from somewhere
else. The other problem is that the + terminal only sits at around 6 to 9
volts when the engine is running, so the choke won't get the full 12 volts
that it is designed for; it will be slow to lean out. Nothing catastrophic,
but I'd recommend getting the choke voltage somewhere else, ideally where
there is a full 12 volts when the engine is running and zero volts if the
engine is not running, regardless of whether the ignition is on.
Travis
> supply for the choke. a switched BATT lead off the ignition switch is an
> option. ( voltage on when engine on, voltage off when engine off)
> John Szalay
> 73 GMC "WBY"
John, there's a little potential problem with this: the + coil lead on the
old Kettering (points) type system is downstream of a ballast resistor (it's
resistor wire in the wiring harness on your coach.) Thus putting the
electric choke in with the ignition coil pulls down the voltage available to
the coil by a fair amount. Apparently not enough to cause you problems when
everything is normal, but I would expect you to experience misfiring from a
low battery sooner than you would if you took this voltage from somewhere
else. The other problem is that the + terminal only sits at around 6 to 9
volts when the engine is running, so the choke won't get the full 12 volts
that it is designed for; it will be slow to lean out. Nothing catastrophic,
but I'd recommend getting the choke voltage somewhere else, ideally where
there is a full 12 volts when the engine is running and zero volts if the
engine is not running, regardless of whether the ignition is on.
Travis
> Actually, I was thinking of tapping onto the center isolater terminal.
> Should only be hot when the alternator is charging.
>
> Patrick
That will work fine---it's the output lead of the alternator and, providing
your isolator doesn't short, will do exactly what we were discussing. Diesel
pickups didn't have that option, so the ignition sense lead on the
alternator is what they used. Either will do fine in the GMC.
Travis
> Should only be hot when the alternator is charging.
>
> Patrick
That will work fine---it's the output lead of the alternator and, providing
your isolator doesn't short, will do exactly what we were discussing. Diesel
pickups didn't have that option, so the ignition sense lead on the
alternator is what they used. Either will do fine in the GMC.
Travis
>> We have the coil ign, ( 73) so I used the + coil input voltage as the
>> supply for the choke. a switched BATT lead off the ignition switch is an
>> option. ( voltage on when engine on, voltage off when engine off)
>> John Szalay
>> 73 GMC "WBY"
>
>
>John, there's a little potential problem with this: the + coil lead on the
>old Kettering (points) type system is downstream of a ballast resistor (it's
>resistor wire in the wiring harness on your coach.) Thus putting the
>electric choke in with the ignition coil pulls down the voltage available to
>the coil by a fair amount. Apparently not enough to cause you problems when
>everything is normal,
>
>
Noted: and I will be moving the choke lead to the alt. output terminal...
Thanks.............
John
>> supply for the choke. a switched BATT lead off the ignition switch is an
>> option. ( voltage on when engine on, voltage off when engine off)
>> John Szalay
>> 73 GMC "WBY"
>
>
>John, there's a little potential problem with this: the + coil lead on the
>old Kettering (points) type system is downstream of a ballast resistor (it's
>resistor wire in the wiring harness on your coach.) Thus putting the
>electric choke in with the ignition coil pulls down the voltage available to
>the coil by a fair amount. Apparently not enough to cause you problems when
>everything is normal,
>
>
Noted: and I will be moving the choke lead to the alt. output terminal...
Thanks.............
John
