Electric chokes began to be using on the Mustang in the '73 model year, and were then only a supplemental device, not a standalone system. All 71-73 chokes were heated via a hot air stove in the intake or exhaust manifold. The heater hose was also used as a supplemental heating strategy to limit choke "on" time and reduce emissions. The 73 electric choke had an internal thermistor that activated it only above 60°F, to open the choke quickly in warm conditions.
The stator wire ( white w/black stripe) only provides around 6V with the engine running, so it may not work satisfactorily with a 12V choke. Another strategy is to use the stator to energize a relay to power the choke with a full 12V.
HemiKiller,
I need to look at our unmolested 73 Mustang Vert's 302 2v 2150 carb. I do not recall seeing an exhaust manifold heater tube on it, just the electric choke. But, at the time I was working in that area I was only interested in the electric choke as the choke was not coming to a fully opened position for a long, too long, period of time, and the plugs were loading up. I did a quick check on the electric heater element and found it was getting current, but no AC amps flowing through the circuit when cold. A new cap fixed the issue. I will look at some photos and videos to see if I accidentally got the choke area of the carb in frame. I believe I may have with at least one YouTube video I posted a while ago.
No matter, there are so few folks who understand about the 6v AC at the Stator terminal, vs 12v+ DC at the output terminal of the alternators. It is refreshing to see your posts in general. And it is nice to see affirmation of things I have seen with and learned about, these First Generation pony cars over the past many decades. I love working on the pony cars. Every time I work on, tinker with, or drive one I am 19 again. And lucky me, it turns out Lynda (wife) is a MustangShelby Chick! She found both of out 73 Mustangs, and was very helpful in me navigating the waters when we purchased the 69 GT500, 97 Del Sol SI (another one she found), and the 2020 GT500. And she is the videographer for most of the How To YouTube videos posted under my channel (Gilbert Hale).
Have you seen, and downloaded the various emission control engine vacuum schematics I have posted in other threads in this forum? If not, they are attached here. The 67-72 calibrations were put out by The Mustang Barn. I, with their permission, assembled all of their PDF files into a single PDF, group by year and sorted by engine. They made the PDFs available for no fee, and I did the same with the consolidated PDF file. Feel free to share with anyone you deem needing it.
The other file is a snippet from the 1973 Mustang Shop File, Volume 6 where finally we have some good calibrations made available. I added 3-15A and 3-16A for the 73 351C 4v (man and auto tranny) calibrations. I do not recall where I got those from off hand. I should have included that in the two affected pages. No matter, they are embedded in the snippet. I may have some annotations in the snippet, but I do not recall seeing errors that I felt needed to be corrected in that snippet. In the 73 electrical schematics I have pointed out a few errors, and added some enhancements that I and others have found. If that interests you email at
[email protected]
and ask for my copy of the Forel Publications 1973 electrical schematic. I have purchased a few copies of that publication, thus have no problem making it available to you, as I am certain you will benefit from the items I enhanced and annotated...
Of course, anyone else reading this message is also welcome to download and use the attached files also. I do not mean to hijack the thread in order to try to have a secretive message posted for HemiKiller only... I see plenty of other folks also with a high level of familiarity and great comments/answers/suggestions "out here," not just HemiKiller and (dare I say?) myself. it is just that his comments re: the electric choke and Stator terminal struck me as being really out there in the land of rarely seen details on these older vehicles. It is refreshing...