1987-1993 Alternator tips
1) Blinking Alternator light on dash?
On my 87 5.0 the alternator light would flash intermittently, thinking that the original 149,000 mile alt had worked longer than I would expect it to & that it was making its last volts, I was planning to upgrade it to the 130 amp unit (see tech section) and thought it was time.
Because of the intermittent blinking I was concerned that a wire might be loose or had a bad connection. It turns out that all it needed was to clean the connections to the alt.
Slowly pull out the 2 connectors to the alt & clean out the oxidation on both alt & connectors, I also sprayed silicon into them thinking that it would reduce moisture & further oxidation. The result: no blinking alt light.
Again... there may be other reasons for the same situation with your vehicle but this may help those who suffered from my exact problem...
2) Replacement ALT (Original 65-75 Unit) / Clocking Issue
Be Aware that all Replacement / Remanufactured Alternators are not clocked correctly.
I've recently noticed this when I needed a quick replacement alt for and 87 5.0/manual trans/A/C. I will assume its true for all 87-93 V8 Mustangs. I looked at these alts from AidAuto, Autozone, Pepboys, Straus & Ford & were all the same.
my 87 (5-speed) The different clocking was too far off to plug in the
Most of the stores will sell the 75Amp (which is better but still low) unit even though the manual stangs(87/93) came with a 65Amp.