Aerostar alternator question

Im trying to test my alternator circuitry for my 91 Aerostar 3.0. The dammed fuse link keeps burning out and the haynes book gives some steps on testing. One of the steps is to touch the "F screw" with the positive of a Voltmeter while the other on the case. My question is.......where is the "F screw" located on this alternator? The haynes book gives no loction or picture to it. There is a threaded female srcrew hole on the back but nothing is atached to it. Is something supposed to screw into that hole? This alternator has 2 connectors one for the b+ connectors and the other for 3 other wires. Would appreciate any advice

Reply to
Edwin T.
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I dont think youll find a "f screw". That book has old general info in it sounds like. What fuse link blows? the one to the battery positive, on the large wire from the alt?

Reply to
Scott M

Yep....large black and orange stripe wire. Ive replaced it with some wire but that also burns out. Im guessing its a short somewhere. Ive checked some older threads at google on the topic and one person had a similar problem back in 2000. He eventually had to change his alternator since it was shorting within it. (i guess) Now im trying to see if its my alternator also. But I dont want to go off and spend 40 bucks on a rebuilt one yet till Im sure it isnt something else.

Reply to
Edwin T.

do you have a voltmeter? check the voltage at the battery with it running. Does it cook the wire right away. It should be around 13.8 -14 volts no more. Is your battery good and charged?

Reply to
Scott M

it runs about 13 to 14 when van idles correctly. However after awhile the idling lowers down (when not moving)and charging seems to lower to 12.60 when lights are on. But once rpm goes up...... charging increases. Ive had this problem for about 2 years and instead of buying new fuse links at the dealer,....Ive simply replaced it with regular wiring (somewhat smaller than the black & orange striped wire...but then again...so are the fuse links themselves) However.......over time I have replaced them with thicker wire so as to last much longer. They seem to slowly burn up and corrode. The article I spoke of earlier is here.....

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Reply to
Edwin T.

Sorry bout that......the link doesnt seem to link to the article

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Reply to
Edwin T.

So it doesnt go over about 14 volts? Rev it up and try it with the lights, ac, high blower on/then off too. Sounds like its ok. Maybe your problem is not making a good connection at your wiring "patch". Clean all your connections near the battery. You can buy fuseable link wire by the roll if you want. What size are you putting on it? 16? use a bigger one if need be. Make sure you get a good connection. If the alt isnt overcharging then test your battery too. A bad battery will pull too much amperage for the link and the alt. Do you have any extra electrical stuff on the car?

Reply to
Scott M

just your average stuff. Radio, heater, Ac (which doesnt work) I guess maybe I should put a fuse link on and see if it will burn out.

Reply to
Edwin T.

Reply to
Thomas Moats

Very true, but I seriously doubt this guy has a clamp on amp meter which would be very nice to look at the alt wire :)

Reply to
Scott M

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