sjhafa Posted November 2, 2005 Share Posted November 2, 2005 Can someone help me what the "S" terminal is? Im doing the wiring for the JTR V8 swap It says connect the black/white to the "S" terminal on the starter solenoid (72 240 and 350 chevy with HEI). I found it mentioned quite a bit, but never explained it. Is it the smaller of the 2 terminals? Thankzzz Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 2, 2005 Share Posted November 2, 2005 There should be a "S" imprinted on the soleniod right at the terminal. The other terminal would have a "R" If memory serves me right, with the starter was bolted to the engine, the terminal closest to the center of the engine would be the S terminal. Quote Link to comment Share on other sites More sharing options...
sjhafa Posted November 2, 2005 Author Share Posted November 2, 2005 Thank you, I'll take a closer look in the morning. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 2, 2005 Share Posted November 2, 2005 S- Is for Start and R- is for run.When you turn your key all the way on you send power to the S wire that ingauges your starter and spins the motor. When you let off the key after the motor is running on its own the power stops going into the S wire and stays going into the R wire allowing the car to continue to run... Does that make sense? That's not how it works, the "R" terminal is a leftover from the oldskool way of building cars. No Chevy V8's have actually used the R terminal since the very early 70's You see that terminal is for a car equipped with a points style distributor. Those ignition systems require a ballast resistor or the coil would fry itself in a short period of time. The "R" terminal is a bypass to allow full voltage to the coil during startup. I didn't bother explaining the purpose of the R terminal because it is of no use these days. (unless you are actually running a points style distributor?) Quote Link to comment Share on other sites More sharing options...
sjhafa Posted November 2, 2005 Author Share Posted November 2, 2005 Accually I miss posted it should read "connect BLACK/yellow to the S terminal. I have 2 terminals the cable from the battery and the larger white wire go to the large lug on the starter, so Im assuming (there is that word again) the black/yellow goes to the other. I can't see any "R" or "S" on the starter solenoid.This is also an HEI set up Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted November 2, 2005 Share Posted November 2, 2005 Grayzee is right, it was used for points and provided power during cranking so it would fire. Not used with HEI. Oldskool, that's for sure, that's why we are still here, to teach you young'uns! Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 2, 2005 Share Posted November 2, 2005 Grayzee is right, it was used for points and provided power during cranking so it would fire. Not used with HEI. Oldskool, that's for sure, that's why we are still here, to teach you young'uns! Are you calling me old? Speak for yourself! LOL Quote Link to comment Share on other sites More sharing options...
sjhafa Posted November 3, 2005 Author Share Posted November 3, 2005 "Young'uns" Ha, I like that too, im 41 but when I work on this project im a teenager all over again, but like most I couldn't afford it back then. Life is grand. Thanks. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted November 3, 2005 Share Posted November 3, 2005 Well, Gray is Gray, I guess the call sign kind of says it all. I'm 42, so 41 isn't old either. My friends are mostly in their 20's, so they refer to me as the "old man" and "ol' skool" too. If you can't laugh, then you should! You guys are all great. Quote Link to comment Share on other sites More sharing options...
love-my-V8-280Z Posted November 3, 2005 Share Posted November 3, 2005 I will remove my post.. It is incorrect... I have just done a upgrade and did only hook one wire to the soleniod... Quote Link to comment Share on other sites More sharing options...
sjhafa Posted November 4, 2005 Author Share Posted November 4, 2005 I removed the starter today to get a better look at the soleinoid. I missed it before but it was marked with an "s". Thanks again. Only 2 remaining wires to go and they are both black and white and go the the HEI. I just have to figure which is which because they are not marked and no protective sleeve. Then im good to go. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 4, 2005 Share Posted November 4, 2005 There are only two wires that go to the HEI. (other than the 3 that go from the base to the cap) Of the two, one is to power the HEI unit and has 12+ when the ignition switch is turned to "ON" You can easily check for that with a test light. The remaining wire is the one that goes to your tachometer. Quote Link to comment Share on other sites More sharing options...
sjhafa Posted November 4, 2005 Author Share Posted November 4, 2005 Thanks GrayZee, I just did that with a test light. Im good to go! Only thing remaining now is to run the fuel line. I appreciate the help Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 4, 2005 Share Posted November 4, 2005 Hey no problem, that's what this site is for Quote Link to comment Share on other sites More sharing options...
bschiltz Posted February 8, 2007 Share Posted February 8, 2007 There are only two wires that go to the HEI. (other than the 3 that go from the base to the cap) Of the two, one is to power the HEI unit and has 12+ when the ignition switch is turned to "ON" You can easily check for that with a test light. The remaining wire is the one that goes to your tachometer. Can the HEI draw power from any 12V keyed source? I'm doing a 280zx, so it's a different beast than the S30's as far as wiring. Should I just one of the 12V wires from the now redundant ignition relay? Quote Link to comment Share on other sites More sharing options...
datsunlover Posted February 8, 2007 Share Posted February 8, 2007 Any 12 volt source will power the HEI, BUT; Whatever you use, it MUST stay live 12v even with the key in the 'start' position. It took me an hour chasing wires to figure this out after I got my rx7 back (sold it two years ago to a friend, bought it back last summer) in non-running condition. Every time I cranked it, the 12v to the ignition cut off, so I got no spark and a lot of flooding.... it would have helped if the timing was close too.. Quote Link to comment Share on other sites More sharing options...
bschiltz Posted February 8, 2007 Share Posted February 8, 2007 Ok, thanks. I'll find something in my wiring diagram, which is invaluable! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted February 8, 2007 Share Posted February 8, 2007 Any 12 volt source will power the HEI, BUT; Whatever you use, it MUST stay live 12v even with the key in the 'start' position. It took me an hour chasing wires to figure this out after I got my rx7 back (sold it two years ago to a friend, bought it back last summer) in non-running condition. Every time I cranked it, the 12v to the ignition cut off, so I got no spark and a lot of flooding.... it would have helped if the timing was close too.. LOL I could see that happening to me. Had to have been frustrating. Quote Link to comment Share on other sites More sharing options...
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