No voltage at field terminal? April 30, 2008, 08:35:05 PM Once I got my t-bird running a couple weeks ago I went a bit overboard and decided that I'd install my 3g without any harness kit or real idea what wires went where. Well, turns out I must've shorted something out because now, with the old alternator back in place (just for now till I find out if either of my 3g's are any good) it's not charging. I've found though that the alternator will start to charge if I momentarily jumper the positive battery terminal to the field terminal on the back of the alternator and will stay charging until the next time I start it.So... what did I short out? Is there a fusible link somewhere along the way there? or did I kill my old voltage regulator again?PS - Sorry if it's been asked didn't have a lot of time to search. Quote Selected
No voltage at field terminal? Reply #1 – May 01, 2008, 12:59:49 AM I am guessing you have an external regulator and a "battery" light on your dash.Here is how it is supposed to work:1. The "A" terminal of the regulator is hot at all times.2. The ignition in "run" should put voltage on the "I" terminal of the voltage regulator. This turns on the field current and lights the battery light on the dash. (this is what's not happening).3. When the alternator starts turning it generates a 'stator' voltage which is wired to the "S" on the reg. This keeps the field current turned on and turns off the battery light.When you jumper voltage to the field terminal you are compensating for what didn't happen in step 2. Quote Selected
No voltage at field terminal? Reply #2 – May 02, 2008, 11:08:28 PM Is there a fusible link somewhere that I might've broken? Quote Selected
No voltage at field terminal? Reply #3 – May 02, 2008, 11:40:46 PM Quote from: Ifixyawata;216878Is there a fusible link somewhere that I might've broken?Nope.How about a little info about your car!!Is it an external regulator?Does the battery light come on with the ignition in RUN?Do you have voltage on the green wire to the "I" terminal of the reg with the ignition in RUN? Quote Selected
No voltage at field terminal? Reply #4 – May 03, 2008, 11:41:37 AM D'oh! Sorry, been rather out of sorts lately. The car does have an external regulator. I switched the gauge cluster last fall, but the car had originally come with an "AMP" light with the battery icon over it. Now I have a full buttstuffog cluster in it and no lights come on when the key is turned to ON/RUN.Once I get a chance to find my multimeter I'll tell you if I have any thing at the I terminal. Quote Selected
No voltage at field terminal? Reply #5 – May 06, 2008, 07:17:31 PM Ok, I checked it and I got no voltage at the I terminal in RUN. Quote Selected
No voltage at field terminal? Reply #6 – May 06, 2008, 09:11:04 PM The light green/red wire from the regulator I terminal, that used to go to the battery light on the dash, has to hookup with the red/light green wire that used to go to the other side of the battery light. Quote Selected
No voltage at field terminal? Reply #7 – May 07, 2008, 04:40:39 AM So does this mean that it's a result of not having a battery light? This charging issue doesn't seem to coincide with my changing the cluster, but I'm guessing the cluster is a good place to start looking? Quote Selected
No voltage at field terminal? Reply #8 – May 07, 2008, 09:41:15 AM Hmmm...I had a feeling this was the issue all along too. Hell, even I had that problem in the convertible, when I went from the buttstuffog cluster to aftermarket gauges. Forgot to splice those wires together and...well, let's just say AAA was involved after that. Yeah, it's probably due to the cluster change rather than the 3G install. You would just need to hook those two wires together and then you *should* be able to generate an electric field. In talking to Tom it was suggested that I could have added a small light to that splice so that I'd get a warning light along with the gauge (and to also act as a slight resistor), but the specs were close enough that I didn't HAVE to use a resistor or light. So far it's been 3 years with no troubles at all. Quote Selected
No voltage at field terminal? Reply #9 – May 07, 2008, 12:34:46 PM The Turbo's with the ammeter run 12v directly to the I terminal of the reg with no bulb or resister in series. Quote Selected
No voltage at field terminal? Reply #10 – May 07, 2008, 04:32:58 PM The thing is, it seemed to charge fine between the time I put the buttstuffog cluster in and when I attempted the 3g. I know this because I checked the battery's voltage with the car running before I pulled the old stuff out and it showed a steady 13+. The first time I started the car with the 3g wired in I did see a spark from the right side fenderwell area, so I know something shorted or somethin' from that side. Quote Selected
No voltage at field terminal? Reply #11 – June 12, 2008, 07:28:34 PM I decided to get a voltage reg for it today and try that.. I'll update once I put it on and try it. Quote Selected
No voltage at field terminal? Reply #12 – June 12, 2008, 07:54:56 PM Nope, not a god thing. Sweet.Anyone point me in the right direction? This can't be something very complex... Quote Selected
No voltage at field terminal? Reply #13 – June 12, 2008, 08:36:12 PM Reread this thread and you have your answer. Quote Selected
No voltage at field terminal? Reply #14 – June 13, 2008, 08:16:18 AM That's it. I hereby relinquish my license to work on my own car... I was so sure that my cluster swap had nothing to do with the alt problems that to this point I hadn't touched the cluster. Well, at my wife's recommendations I pulled the cluster and sonofabitch if the plug wasn't halfway unplugged from the back of it. Plugged it in and all is well. Thanks again... maybe next time I'll read first. Quote Selected
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