97 F150 is dying while driving. Battery is not getting a charge from Alt
Ok, bought a 97 F150 4x4 to fix up. Installed new battery and alternator but
battery is not getting charged from ALT. Alt is only putting out 11.8 volts while
running with lights and fan on, 12.0 while idle with nothing on. Had Alt tested
and it is fine. Brand new battery. Replaced EEM relay and ignition module
under steering wheel. Checked for ground issues, nothing. Positive wire has
continuity to frame. Parts guy said that it may be the Body Control Module.
Any ideas on wtf is wrong?
If your positive wire goes to ground you have a problem.
First check the wire to the back of the alternator and make sure it has 12 V also your alternator should be putting out at least 13.6 Do you have an extra regulator or an internal regulator on that alternator
Check for blown alternator fuse
I checked the back of the Alt. It has 12V. I just took the Alt back to the store and exchanged it. Same issue. It has an internal regulator. I checked the alternator fuse that is by the main fuses. It's a twenty amp. It wasn't blown, I cleaned the contacts to make sure that it was getting a connection. I'm still just getting 12V out of the alternator. Battery was drained down to 40 percent. The parts guy suggested that the body control module may be the issue. Any other thoughts before I spend another two hundred dollars?
Let me get to my Pc and log in and look at the wire dish and I’ll get back it’s going to be a few hours if that’s ok
With the ignition off and no electrical loads on, connect the negative lead of 73 Digital Multimeter to the battery ground cable clamp. Connect the positive lead of the 73 Digital Multimeter to the battery to starter relay cable clamp. Read and record the battery voltage shown on the 73 Digital Multimeter. This is called base voltage and will be used in later tests.
this is for a 4.6 not sure what you have
did you look at the 175 amp meg fuse
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I suspect you have a three wire alternator connection. The field reference wire controls the amount of charging. Since charging amount is determined by the needs of the vehicle, your problem may be there. When the lights are on, the alternator should charge more. Since it charges less, the internal voltage regulator may not be working properly. This often occurs when rebuilt alternators are purchased and the wrong regulator is installed.
Ok, replaced battery, alternator, and EEC. I am still having the same issue. I have checked EVERY fuse in the truck. Throwing money at the issue isn't helping me
checked red hot wire from fuse to alt. with bulb and volt meters, no issues in wiring. Missing airbag fuse, will replace asap to see if that may be the issue
Airbag fuse was not the problem (gasp!). I didn't think that it would be though, but another forum suggested it and I'll try anything at this point. I'm going to take the new alternator back and go with the bad internal voltage regulator theory. That is the only thing that makes sense to me. This will be the third alternator. If this doesn't work, anyone looking to buy a clean 97 F150?
Fixed (sorta)! Here's the skinny... the green/red wire that runs to the dash indicator was/is broken in the dash area. I (sorta) repaired the wire and now the alternator is putting out 14.5 amps! I didn't have time to take the dash apart so I ran a wire straight to the positive terminal on the battery and put a toggle in between the two. It will work until I get time to tear the dash apart.
