Wagn

First time Mustang owner, yay! What it is: '92 LX convertible with dual plug DIS 2.3, and what its doing: Starts when it wants to, and once running, charges when it wants to.
When it doesn't start, I noticed the fuel pump does not come on. Both pump and inertia switch checked okay. Something isn't turning everything on properly. What would that be?
The alternator passed the check test at an O'Reilly's but the charge is not getting back to the battery. All the connections, grounds, solenoid, and fuse links are okay. So why isn't it charging? The troubleshooting section in manual only does so much so I decided to ask you all. Oh, and ignition switch checked okay too. Now what? Thanks.

Babybudistmonk

I'll bet you have a problem with your fuel pump circuit, probably a relay. There should be a black box on your passenger side strut tower that has a fair amount of wires coming out of it. Your relay is in there. Only problem is, the relay is hard soldered into the circuit board there. so you either need to break the solders, and replace the relay, or get a whole new box. As far as your battery goes, sometimes those do some funny things when they are dying. How long has the batter been in the car? If it were me, I would get a new one. Should solve that problem as long as everything else checked out ok

dreamer1uk

Hi,

Do you have a volt meter that you can hook up to the battery to see what the volts are when the vehicle is runing? It should be between 13.5 and 15.5v. If its out of range, the voltage regulator may be the culprit.

Did O'Reillys test the Alternator on or off the vehicle?

I would also do voltage drop tests on the feed and ground side of the alternator to rule out any issues with the wiring going to the battery. It should exceed 0.5 feed side and 0.2 on the ground side when you test for the voltage drop

If you can find a wiring diagram, you can see if you have power going to and from the IRCM on the passenger side fender also

Hope this helps.