92 F150 2WD I6 5spd. You know how the alternator gauge has the range of 8-18 volts? Well, the needle is always about right in the middle but sometimes wiggles back and forth while I'm driving. If I turn on the head lights it will stop but sometimes it does it while the head lights are on. Is this a problem or is this normal? I've just never seen a vehicle do this before.

My left blinker stopped working yesterday but the dash light comes on and stays on. I think the front bulb is OK cause I parked behind another car last night and manually switched the left blinker on and off and I could see it lighting up the rear of the vehicle in front of me. This may be nothing more than a bad rear bulb but I thought I'd throw it in there.

While I was testing the blinkers using the rights and lefts to identify where on the lense to look, I noticed that the headlights dim with the rythym of the blinkers. As the right blinker comes on the headlights dim a tad. Is this normal or an indication that something needs a fix/rebuild?

Sometimes if I let off the clutch and don't gas it enough and the engine RPMs drop way down all of the electricity will go off for a second. Normal?

 

Sounds like alternator is not charing the Battery fully. I would pull the alternator and bring it to your local parts store that has a tester to see what it is doing. They will test for free. ie Autozone or Advanced Auto. You let it go too long and your battery will need replacing as well if it does not need to be already. Good luck.

PS: if you have a multi tester and know how to use it you can check it yourself to see it is charging at like 14.4+ volts. But you better off at a store where it is done under a load.

 

Ford Trucks Carry A Ground For The Lighting System Mounted Right At The Front Of The Radiator Support Drivers Side, And Passenger Side. The Problem You Just Described Sounds Like A Grounding Problem. As Far As The Altenator Ford Gauges Are Very Erratic, When You Turn On Any Thing That Draws A Load The Gauge Will Move Up Or Down Depending On The Load

 

Neither My 79 F150 Nor my 93 F-150 do that. Get in my Chevy Van and it does that because the alternator is nearing the end of its usable life span. Being that these alternators have the voltage regulator inside them they last about half the life of the older style systems that had external ones.

 

I'm gonna check the grounds as soon as I have a day that I get home before dark as it is 4 degrees today and it gets real cold in the dark (you know, banging your knuckles on sharp steel things under the hood.)

I noticed something since I started this thread. If I'm driving and the alternator gauge on the dash is wobbling back and forth and I turn on the headlights, the gauge needle stops wobbling but sometimes all the electricity in the truck shuts off for a moment. The radio will turn off and back on and the engine will act like it's been turned off and on. It sputters and then revs up high again like when you first start it. I noticed the engine sputter/rev up all on it's own this morning without me messing with anything.

Does this shed any light on things?

 

Check your alternator, check all the battery connections and check the body ground from the engine to the firewall. Should be a wire strap with loops on each end.
I would guess your voltage regulator is bad, I have seen them either totally go out or kind of spit and sputter like yours.
It is normal for your guage to move around slightly with different power demands Not too much though. It is just displaying the instant it takes for your voltage regulator to adjust the output of the alternator.

 

What do you mean when you say check the alternator? Do you mean the connections to it?

My guess was also regulator, or alternator. I figured that maybe the brushes are about shot and starting to ground out.

 

If you take it to just about any auto parts store, they can check the alternator on the truck while it's running to see if it's putting out the voltage it should be. If it turns out that it's a bit on the low side, that could most likely be the problem. I'd check all the grounds and attached wiring too while you're at it just to be sure, at least that way if you wind up putting in a new alternator you shouldnt' have any more problems with it.

 

Eeek. This sounds so deja vu of what I'm wrestling with right now. Here's a quick rundown of what I've got and where I'm currently at so you can compare notes and take an appropriate path:
92 f150 4wd 351 e4od with about 160k on the clock. This was my wifes truck from the days before I even met her and she bought it new so it's been well maintained.

Last couple months the battery wouldn't hold a charge. Optima red top that's less than a year old. Finally figured it was the alternator since that was still the original one. So even if it weren't the problem, it's due for a new one anyway. So it gets a new alternator and battery (killed the battery beyond revival...thank you optima for 3yr full replacement). Drove it a few times afte that and all was good.
A couple weeks ago I was driving it. Wasn't having any issues. I made a couple stops and it was fine. Started without a hitch as usual. Then we stopped for lunch. Went to leave and I had no power anywhere. Wouldn't even turn on the dome light. Got the jumper cables out and the starter spun her over like nothing at all had gone on, which was kind of weird because my experience has been that if you kill the battery that far down you need to wait a few with the jumper cables on to get enough charge before it'll do anything. In this case the cables had been on like 10 seconds...literally.
Got back to my buddy's place and shut it off, same thing. Well I got other things to do so figured I'd just jump it again when it was time to leave. At one point a few minutes later I need to get something out of the cab and I notice when I opened the door the dome light was on and the door buzzer was going (keys in ignition). I crank it over and it fires right up. Ok, so looking like intermittent problem (aka: weak short). Later it's time to leave, no go. Break out the jumper cables again. Again it fires right up, but I do notice the voltmeter is twitching like an epileptic seisure. I go to flip on the head lights and the second I do it kills all the power and the engine dies like I turned the key off. (sound familiar?)

Well I managed to get it home and thus far it's not looking good. So it's got a new alternator and battery (as mentioned), and in the process I've also thrown in a new starter relay and ignition switch (just because they were cheap and easy and I was seeing some things that had me speculating they might be the culprit). I've spent a few hours pouring over the wiring harness looking for any place where it looks like it may have frayed through or seen some corrosion. Thus far I haven't found anything. Last weekend I was checking for voltage on the signal wire for the starter relay (with my wifes help turning the ignition key) and it was erratic. One minute I didn't have anything, then the next it did. As of today the truck is starting, running and behaving just fine. But I don't trust it. I would just replace the whole friggin wiring harness from the firewall forward....if I could get a new one, but that's another story. So it's looking like I'll need it to start misbehaving again so I can start ripping the shielding and tape off the harness to start tracing out wires one by one.

Soooooo, that's the long version. My suggestion to you (based on what I've been through already) is you can save yourself from just throwing some parts at it. Get your alternator and battery tested just to eliminate those variables. Wait for it to behave badly and start getting cozy with a multimeter.

Damned if I can't find my factory wiring diagrams too, that really sucks because this is when you really need them. gggggrrrrrrrrrrr

 

Check you battery terminals sounds like a bad connection.

 

EBR, here are a couple of wiring diagrams based on your truck. If you need a specific one let me know what you are looking for.

http://img352.imageshack.us/my.php?i...l92fordch0.jpg
http://img403.imageshack.us/my.php?i...92ford2pr4.jpg

 

that was the first thing checked.

 

[QUOTE=Mr Alias]EBR, here are a couple of wiring diagrams based on your truck. If you need a specific one let me know what you are looking for.

http://img352.imageshack.us/my.php?image=electrical92fordch0.jpg
http://img403.imageshack.us/my.php?image=electrical92ford2pr4.jpg[/QUOTE]

Thanks for the effort, but I have those same crappy diagrams on CD. They give one small snapshot of a specific circuit, but not the big picture of how it fits in the grand scheme. I like the old hardcopy schematics I had (errrr...have hidden somewhere) that make it much easier to browse what's where. I especially like how my old ones would show all the connectors in between points A and B and which terminal on the connectors were connected to what. Classic example: in those links it shows the ignition switch in one part of the diagram and the battery in the other. Well, at a very minimun the wiring has to go through the firewall. That diagram doesn't show me which terminal on which connector a wire is going through said firewall. That's the difference between what I'll call a wiring 'diragram' vs. 'schematic'.

I appreciate the effort, but it's not a lot of help.

 

Now that I'm really paying attention here's what also happens. As I'm driving, sometimes when I hit the brake pedal or turn on a turn signal, the radio goes dead. Nothing happens to the engine but the radio will just turn off then back on.

I've also noticed that sometimes as I'm driving the engine seems to restart. It bucks for a second and then revs high like it does when you start it. Either of these things will occur without the other, i.e. radio goes off with no effect on engine and vise versa. It does seem like a short somewhere. I guess I'm gonna have to get out there and start cleaning connectons. it's just too darn cold to do it before next week.

 

Interesting. I have noticed that if the power is lost on mine, when it comes back on there's a servo in the CD player that goes through some girations. (meaning it lost power as well).

Between the two of us and how similar some of the experiences are, I'm beginning to think the problem is under the dash (vs. in the engine compartment). hmmmmmm. I may be able to spend some time on mine this weekend. I'll post back to let you know what I do and find (or don't find).