Hello All, after repairing my headlight assemblies and header panel as well as fixing my cooling issue another issue has arrived.

I slowly lost voltage on my meter and as the battery died the gauge read below Normal. I tested the batter which showed only 12 V off of the terminals (once off the charger) and the alternator was only providing 9V. So, naturally I replaced the alternator. No help. Volt meter still reading low and the alternator was providing low amps still. So, I thought maybe the battery was not allowing the charge so I replaced that and have the same problem. Any ideas??? Volt regulator? My connections are good so...

Thanks in advance...

 

Forgot to mention... The vehicle is a 1994 Ford F 150 w/a 5.0 L Thanks...

 

it could be corroded broken and down rite worn out wires or maybe even a bad ground

mine was doing the same thing but i got lucky and the alternator fixed it

 

You need to take this as a learning experience. Never replace an alternator without some basic testing and a bench test at the auto parts store.
When you got 9 volts, the alternator was not delivering anything, the truck was running off the battery only. Either the alternator was not "turned on" or the output was not getting to the electrical system. There is a wire going to the alternator from the ignition. This is green with a red stripe. Disconnect it and check for voltage with the ignition off and get 0 volts. Turn the ignition to run and recheck. Should get 12 volts. If this is ok then the wire delivering the output is probably the culprit. It has a fusible link. This is a thick spot in the wire and covered with insulation. When bad it will feel rubbery and might be able to stretch it. Disconnect this wire and check for continuity. If you don't have it , the link is blown, and the wire needs to be replaced. Don't cut the fuse out and splice the ends together. This will leave the system unprotected and can cause a fire in a few seconds if something goes wrong. You might have another problem that caused the link to blow, but sometimes they just get old and give up. If you replace it, check all the solenoid connections and battery terminals for good connections. Hope this helps.
Good luck Frank

 

Ok so i have two wires that come in to the top connector of the alternator and the bottom clip has only one wire that runs up into the top connector. Which of these should I check. I charged my battery and ran the truck and as it lost power it would from time to time start charging but quit after only a few seconds. This seems really odd to me....

So again, which wire should I be checking and why do you suppose the voltage would jump like that. Currently, for the most part, I believe the truck is running only on the battery...

Thanks,

Adam

 

Do you have a 3G alternator? I think the 94 came with it, but not sure. A 3G has an internal fan, the 2G has the fan external right behind the pulley.
Here are links to the wiring diagram for each.

http://fordfuelinjection.com/public/...ALT_wiring.gif

http://fordfuelinjection.com/public/...ALT_wiring.gif


In the case of the 3G, the y/w wire is used by the voltage regulator to sense the voltage and vary the alternator output. If your voltage is coming and going, and you are sure the alternator and voltage regulator are ok, sounds like you have a bad connection that is intermittent. Could be at the alternator, or the solenoid. I think a bad or missing ground could cause this also. Is the ground from the firewall to the engine present and making a good connection?
Hope this helps.
Frank

 

So, how does one find a replacement fusible link. All I could find at the parts store was fusible link primary wire. I need the actual link correct?

 

Is your fuseable link blown? If yours is charging part of the time, the fuseable link can't be blown eh?

When I converted from the 2G to a 3G alternator, I went to an auto stero shop. Bought a fuse holder with a cover, and a big fuse. Think it was 175 amp.
Looks like this.

http://fordfuelinjection.com/public/...se-mounted.jpg

Good luck
Frank

 

Is the fuse the wire itself or is there a fuse built in to the wiring? I was under the impression that the link is the fusible wire. If I need more then the wire where would I find this. Currently I have the two wires from the alternator wired together with a connector and then the fusible wire on the other end running to the solenoid all wrapped in elec tape. Is this incorrect? Dangerous?

So, after all my part throwing (yes, lesson learned) I noticed a bulge in my negative battery wire. I razored it back and noticed it is very corroded. So, I think I just need to replace this. Any tips here or is it just a bolt on the block?

thanks,

Adam

 

Do you have a 3G alternator? I think the 94 came with it, but not sure. A 3G has an internal fan, the 2G has the fan external right behind the pulley.
Is your fuseable link blown?

 

it is 3g. turned out to be nothing wrong with the fusible link so I replaced that wire while crimping the two coming in together in a connector. Any advice for getting to the ground on the block?

Adam

 

Just clean the block where it makes the connection. I use emery cloth or sandpapaer in a pinch.
Put it on tight, but not breaking the bolt tight.
Good Luck Frank