So I just swapped in the 3g alternator. I had it all charging and working with the battery sitting on the fender (wanted the extra room for getting at the wiring and stuff). Put the battery in and it stopped charging. Looked all around for issues and can't gd SEE anything. Running out of daylight and I need to get the car on the road because a wheel fell off my other car (haha... seriously.) I replaced the fusible link going to main harness because it was nasty corroded and hanging on by 2 copper strands, only spliced in a wire. Figured once it was running I would go pick up an inline fuse for it. Any advice GREATLY appreciated. Got about 2 hours of daylight left... maybe.
I swapped to a 3g alternator not too long ago..It was easy and I haven;t had any problems since. heres the thread that I used if you look on post #3 you will see the wiring diagram. http://mmb.maverick.to/showthread.php?t=36192&highlight=alternator+upgrade You maybe disconnected a wire as you put the battery in the tray.check for any disconnected wires.I would take a picture of my alternator but its already dark over here.
Yea it went dark on me, so I had to make the call of shame to wife to come pick me up from where I work on my car at. I checked and triple checked all the connections. I even re-did a bunch of my splices. I used to build cable harnesses so I'm very confident in my work there. I'm all wired up according to the diagrams and it WAS charging. Then I stopped because a guy came by to look at my bronco that's sadly being parted out. I dropped the battery into the tray and boom no more charging. I just wanted to SCREAM! Ok, so when I put the key in and turn it to on but not far enough to start it the alt light comes on, the blinkers work, the gas gauge goes up. Turn it on and everything stops working except the headlights and uh spontaneously my instrument panel lights started working again (they were not previously working at all, that is weird right?). So I am really feeling like I may have to trace back the wire that had the fusible link on it and check for more corrosion and breaks. Awesome... may wind up rewiring a bunch of car tomorrow. Ok so its the yellow fusible-link that I replaced for corrosion. That goes to the headlight switch apparently? When I replaced that link initially it charged, would a bad headlight switch cause a no-charge situation? Also, if that isn't hooked up nothing works at all, not sure if the car starts because I decided not to try and start it. Shoud I have? 1 more thing before I go to bed to try and sleep and not think about this. The black-white wire that the wiring diagram says goes to the electric choke. The PO had cut that wire off when he converted the electric choke to manual (total hack-job) would that not being connected to anything anymore be causing me any grief?
The fusible link has nothing to do with the headlight circuit. The link is in the large gauge wire directly between the battery and the alternator. When the engine is running, touch a screw driver (make sure it's not magnetized before doing this) to the center plug (the one covering the shaft) on the backside of the alternator, it's charging, the screwdriver will be attracted to the plug.
There are 2 wires with fusible links that the wiring diagram shows going to that point. The charge wire from the alternator to the post is a 4AWG wire with a 175 amp megafuse in the middle of it. I am wired per the stupid diagram that everyone links in other threads. I've got an EE and years of following schematics, diagrams, and experience building harnesses. But thank you VERY much for that technique to test the alternator. I am going to check that out. You always have some great advice. Would that be an indicator of a bad regulator? I happen to have an extra regulator handy. My other question though, can a bad headlight switch make my car not charge? I guess I need to check to see if it is drawing excess current. Wish I had remembered to borrow a current clamp from work. Anyway the YELLOW WIRE with the fusible link was keeping me from charging initially. I cut out and spliced the join in that wire (Seriously guys a fusible link is nothing but a smaller wire attached to a larger wire through a splice, so that the smaller wire burns up before the larger wire even gets hot usually with some extra insulation on the smaller wire to control the exact temperature it burns up at) and started charging with no issues. Then an hour later with nothing changed except moving the battery into the battery tray it stopped charging. So I am really suspect that there is something else wrong in that circuit and wondering if anyone else has experienced a no charge situation from a bad headlight switch.
Well the best indicator is that without the alternator sending a charge signal the fuel gauge will not work, it's fully reliant on their being a charge coming off the alternator. Other than that my brother-in-law checked it with the volt meter for me when I started cussing and swearing. Then I checked it with the volt meter. The real annoyance is that the alt light doesn't come on. It is possible that it's charging but there is a heavy enough current draw from somewhere to draw off all the current. Let's put it this way, everything LOOKS right. Everything probes correctly. Continuity everywhere there should be. I just can't figure out where to go next and am grasping at straws. Anyone in the portland area want some free beer?
If the alt light does not illuminate....The alternator will not charge. Could be the bulb failed, could be a bad connection...Could be the wire for the alt light has a break in the harness else where......Check all your connections again. Good luck!!!
Alt light illuminates when the key is turned but the engine isn't started. Thought I said that already? Gotta stop stalking this thread and go work on the car... why isn't it time to take the kids to church yet and go fry my brain tracing wires.
??? The fuel gauge will / should work with the key in the RUN position regardless if the engine running or the alternator turning.
On every late 60s early 70s ford Ive owned or driven when your alt goes out your fuel gauge shuts off. I could explain it to you but theres a article on one of those mustang mod magazine/sites that does a better job than I could. I'd probably get to technical and lose focus explaining the circuits. This yes. I am losing my B+ power when the car turns on and then the battery doesn't charge. The alternator is a ****ing smokescreen. It works fine that circuit works fine. This is why when people keep telling me to go back and check the alt wiring I want to throw my keyboard through my monitor. Do I need a new starter solenoid? New headlight switch? WTF is breaking my car?
Uhh, I don't think you would get too technical, I'm an EE. My Maverick's fuel gauge works by just turning the key to the RUN position. The fuel gauge is powered through a 5V regulator located behind the gauge cluster. As long as you have at least 7 volts applied to the cluster the fuel gauge will work. Even a battery with two shorted cells can supply that.
my gas gauge works if charging or not, if it isnt charging it is in your wiring or the alternator is bad here is a pic of the rear of mine
