How do I tell if my 68 Mustang has an alternator or generator? I've read that Ford changed over to alternators in 1965, but I've also read that generators were used in Mustangs up until 69 or 70. My Chilton book calls it an alternator/generator!!!???

 

Alts have been around since 66

 

I have only had 1 vehicle with a generator, that was a 54 dodge, the difference was distinctly different, fully encased and longer than an alternator. I am willing to bet you have an alternator unless a PO did something really stupid. BTW get rid of that Chilton book and pick up a shop manual, you will be happy you did.

 

if it doesn't look like this its not a gen

 

Mine has the fan blades on the front, but the unit itself is only half or less as long as yours appears to be, so I guess it's an alt. Why do my headlights brighten when I rev up the engine? Weak alternator? Belt is tight. Thanks.

 

only 64.5 mustangs use generator, all other are alternator. essentially the same thing. charges the battery. just that in the generator it uses a coil running in magnets, whereas in an alternator the magnets have been replaced with guess what? another coil. send picture, I'd be very very surprised if it's a generator in there. if you need to replace, then get an alternator

 

Could be weak alternator, dirty or corroded wire connections, loose belt, or even a bad battery. You'll need to get a meter and check the battery with car off, car on, and, if you can a buddy, with the car on and someone revving it. Should get 12.5 volts or so off, and should be 14 or so on. Voltage shouldn't change if it is at 14 on and someone revs it, should stay mostly constant.

 

You need better reading material. Ford switched to alternators in August 1964. Do this- take your Chilton's out to the garden, and using a spade gently place it at the bottom of your mulch pile. Then get a real manual, the Factory Service Manual.

 

You most likely have a alternator on a 68. (it also sits a bit lower on the engine than the generator).

As far as your brightening headlights question: the simple fact is that the engine at idle typically doesn't have enough speed to turn the alternator fast enough to produce the fully regulated cutoff voltage due to current load (headlights and battery charging). I bet if you were to place a voltmeter across the battery, you'll see barely 12 Vdc at idle but around 14.5 Vdc at higher RPM. Its really nothing to worry about if this is the case. If you can get to an auto parts store they have a machine that will check alternator output. (38 -55Amps depending on engine type) You can also try a new style electronic voltage regulator or a 1 wire replacement alternator (they have lots more output available) if you're concerned

 

Dimming headlights at idle is not unusual. On a 289HP, BOSS 302, or BOSS 351, it's normal, they have a large diameter alternator pulley to protect the alternator at high engine rpm.