Gary Lewis Posted January 8, 2019 Share Posted January 8, 2019 What the actual voltage of the stator connection is escapes me. All I knew was that it was supposed to be about half of what the typical output voltage would be (14.5vdc). According to my 1984 FSM: Interesting to note, I kept coming across mentions of a full 12vdc choke. You can see in the chart above. It was done with battery voltage through and oil pressure switch. That would be a nice way of doing it if you were running a full 12vdc...although it would require an extra oil pressure port. One of the reasons I personally stuck with the factory 7.2vdc was that I wanted a run-only signal. I can guarantee you that I'd be that guy that left the key on at some point and baked the element...lol. Now, if I had an easy place to install and oil pressure switch....hmmm... Good find on the chokes and voltages. Interesting that Ford said 7.2V. That's awfully precise for something that surely varies significantly. Anyway, I agree with Steve. You can put a tee on the oil pressure port and put a switch on it. That's the way I have Big Blue set up, with the switch running the fuel pump relay and the other side of the tee going to the gauge. Link to comment Share on other sites More sharing options...
Ferdinand Posted January 9, 2019 Author Share Posted January 9, 2019 Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 9, 2019 Share Posted January 9, 2019 I think this melted thing by my pinky finger is the radio noise capacitor... I am wondering, in the picture below, if this is the same thing? This part of the harness is what I took out of the Boneyard '86 but there are obvious differences between the two so I don't want to assume anything. This red wire with the yellow dashes and the bare metal plug at the end has 12 volts to it when the key is in the on position and when the engine is running: I am actually thinking of powering my choke from there. Thoughts? The capacitor would have a red wire with light green dashes or stripes, and the light green could be taken for yellow. And, it would have 12v on it with the key on. http://www.garysgaragemahal.com/start--ignition.html But, it shouldn't really have 12v when the engine is running as it should be toggling between ~7v and 12v as the ignition fires. Anyway, you don't actually have to have it. If you don't have ignition noise in the radio don't worry about it. And note that the 4.9L didn't even get one. Link to comment Share on other sites More sharing options...
Steve83 Posted January 9, 2019 Share Posted January 9, 2019 I think this melted thing by my pinky finger is the radio noise capacitor... I am wondering, in the picture below, if this is the same thing? This part of the harness is what I took out of the Boneyard '86 but there are obvious differences between the two so I don't want to assume anything. This red wire with the yellow dashes and the bare metal plug at the end has 12 volts to it when the key is in the on position and when the engine is running: I am actually thinking of powering my choke from there. Thoughts? The RFI cap is always a short pigtail off the coil positive. I can't think of any problem using that wire to power the choke heater. BTW All RFI caps are interchangeable, regardless of make, model, or year. In '96 Ford trucks switched from the traditional Aluminum can to a molded black plastic cap, with the same connector as '95 (& many previous years).And note that the 4.9L didn't even get one.My '83 300ci originally had one, and all the documentation I've seen shows it for all engines. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 9, 2019 Share Posted January 9, 2019 The RFI cap is always a short pigtail off the coil positive. I can't think of any problem using that wire to power the choke heater. BTW All RFI caps are interchangeable, regardless of make, model, or year. In '96 Ford trucks switched from the traditional Aluminum can to a molded black plastic cap, with the same connector as '95 (& many previous years).And note that the 4.9L didn't even get one.My '83 300ci originally had one, and all the documentation I've seen shows it for all engines. I wouldn't recommend using the coil power to run the choke as that comes through the ballast resistor, circled below, when the key is in Run. So the coil isn't getting 12v, usually more like 7 volts, and by running the choke on there you'd be getting even less voltage as with more current you'd have more voltage drop - which would reduce the spark voltage. In fact, it might be less voltage than using the stator for the choke. That's why I recommend using the white/light blue wire going to the ignition module as it comes off ahead of the resistor and would have full battery voltage in Run. As for the condensor/capacitor, I've also circled the "All Except 4.9L" that shows in all the EVTM's I have. This one is from the '86 EVTM on Page 26 for Duraspark, but I've also checked the '81 and '85 that I have on the site. Link to comment Share on other sites More sharing options...
Steve83 Posted January 10, 2019 Share Posted January 10, 2019 I wouldn't recommend using the coil power to run the choke as that comes through the ballast resistor, circled below, when the key is in Run. So the coil isn't getting 12v, usually more like 7 volts, and by running the choke on there you'd be getting even less voltage as with more current you'd have more voltage drop - which would reduce the spark voltage. In fact, it might be less voltage than using the stator for the choke. That's why I recommend using the white/light blue wire going to the ignition module as it comes off ahead of the resistor and would have full battery voltage in Run. As for the condensor/capacitor, I've also circled the "All Except 4.9L" that shows in all the EVTM's I have. This one is from the '86 EVTM on Page 26 for Duraspark, but I've also checked the '81 and '85 that I have on the site. This says it was only some early '84 300s that lacked the capacitor: https://drive.google.com/open?id=18eMI8GebF3VZQR0qDUWyksvAgIJt8JhO That implies that older & later 300s were built with it. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 10, 2019 Share Posted January 10, 2019 This says it was only some early '84 300s that lacked the capacitor: https://drive.google.com/open?id=18eMI8GebF3VZQR0qDUWyksvAgIJt8JhO That implies that older & later 300s were built with it. That is interesting! I'd missed that. But, you are right, that sure implies that only early '84 4.9's didn't get it. That would explain why others I've seen had it. And, I'd guess that the statement in the EVTM just got carried over from year to year. Easy to see that done in such a big organization as Ford. Link to comment Share on other sites More sharing options...
Steve83 Posted January 10, 2019 Share Posted January 10, 2019 And, I'd guess that the statement in the EVTM just got carried over from year to year. Easy to see that done in such a big organization as Ford.Yep. There are MANY errors in the Ford EVTMs; even the later ones. I find one nearly every time I study a new cell. And Haynes carried (probably STILL carries) the error about the IMS through several editions. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 10, 2019 Share Posted January 10, 2019 And, I'd guess that the statement in the EVTM just got carried over from year to year. Easy to see that done in such a big organization as Ford.Yep. There are MANY errors in the Ford EVTMs; even the later ones. I find one nearly every time I study a new cell. And Haynes carried (probably STILL carries) the error about the IMS through several editions. Yes, and the trouble always is which Ford publication to believe. I think the more specific one is the best bet. In this case the TSB is more specific to a given year, so it would win. But there's also the publication type to consider. I think brochures, which were on the leading edge, are the least reliable, possibly because the folks doing the manufacturing changed their minds after the brochure was printed. So, with that theory I'd say TSB's are the most accurate as they were written last, well after the fact, to correct a known problem. Link to comment Share on other sites More sharing options...
Steve83 Posted January 10, 2019 Share Posted January 10, 2019 I wouldn't recommend using the coil power to run the choke as that comes through the ballast resistor, circled below, when the key is in Run. So the coil isn't getting 12v, usually more like 7 volts, and by running the choke on there you'd be getting even less voltage as with more current you'd have more voltage drop - which would reduce the spark voltage. In fact, it might be less voltage than using the stator for the choke. That's why I recommend using the white/light blue wire going to the ignition module as it comes off ahead of the resistor and would have full battery voltage in Run. As for the condensor/capacitor, I've also circled the "All Except 4.9L" that shows in all the EVTM's I have. This one is from the '86 EVTM on Page 26 for Duraspark, but I've also checked the '81 and '85 that I have on the site. In the short time I worked at the dealership, I made 2 corrections for the service manuals, and 1 to a recall. What does that tell you about how often there are published mistakes? I forgot to reply to this earlier......through the ballast resistor...Good catch - I never think about that because I got rid of that wiring harness so long ago. So if you're using a 6V heater, and you don't want to use the alternator "S" (for whatever reason), you could use the coil positive/capacitor circuit. It would get ~12V during cranking (actually closer to 11 typically), but I doubt that's long enough to fry the element. Link to comment Share on other sites More sharing options...
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