Long story/ amp lite on

[jlwoods99]

92 f350 2 whl drive. Went to the dump and the battery light on the dash says amps came on. Would go out on the way home then came on and was flashing. I got home, checked the batteries 14.7volts, alternator was putting out 14.3 volts. I had a fuel filter leak, so I went to auto parts store got a filter replaced it. Bled the air and it didn't start right up . Crank crank crank, bled air. Crank crank crank , bled air.only from 1 injector on each side. Batteries slowing down. Put jump charger on it as I was cranking. Once it started up the volt meter on the dash showed about half way charging and the amp light was flashing, the longer I drove it the volt meter climbed higher from center to closer to 18 volts. I know its, not accurate but the higher it got the light on the dash quit flashing and stayed on constant. Could my alternator be overcharging since my volt meter is reading so high? Also I had fuel in the valley around some injectors and it was bubbling. Could this be a leak or was the diesel fuel just bubbling off.

thanks
jim

 

[cpdenton]

Not the same truck, but a similar alternator. My 04 f-150 recently started showing the charge light only at idle. It was producing voltage, but not enough amperage to charge anything. Lit would go back off and voltage would climb at speed, but unhook the battery, and all died. Slapped a new alternator on it and I was good to go.

 

[jlwoods99]

my batteries seem pretty charged up, but when I almost ran the batteries dead the amp lite flashed and voltage showed about half way on the gage. After driving 40 minutes or so the voltage climbed quit higher than I've seen it and the amp light then stayed on constant. And the batteries tested totally fine 14.7. If I thought my alt. was bad I'd expect my batteries to run lower voltage, but there not. Unless I'm thinking wrong about it

jim

 

[jwalterus]

did you check the water level in the batteries?

 

[jlwoods99]

No, never occurred to me. They're 2 year old interstates I think maintainence free. I'll see what I can do.

jim

 

[Wyreth]

14.7 is marginally high. Your voltage regulator could be dying... they're not the most robust part under your hood.

 

[jlwoods99]

Is a voltage regulator internal to the alternator or is it something I can replace?

jim

 

[Wyreth]

should be external. it's the box that sits on top of the passenger side inner fender. it's like a $10 part.

or you could go the way I want to go, read up in the Tech Section, and just upgrade to a 3G alternator.

 

[LCAM-01XA]

Voltage regulator could be external or internal - early '92 with V-belts would have the external VR on the fender as suggested, but a serpentine-belted '92 would have the VR as part of the alternator (which by the way would already be a 130-amp 3G from the factory). It's replaceable either way, just external VR is easier and cheaper. Internal VR does come with new brushes tho, so that kinda makes up for having to pull the alt to replace it.

 

[jlwoods99]

mine has the serpentine belt so that would indicate internal. I look it over sounds like a plan.
thanks!
jim

 

[jlwoods99]

Any ideas on the bubbling around the glow plugs? I said injectors but meant fuel was bubbling around the glow plugs where I spilled some.

jim

 

[LCAM-01XA]

Do you see the bubbles while engine is cold or just when it's hot? Plugs not tight in their holes? The bubbles can be signs of compression leak from the precups past the glowplug threads, what you're seeing is pretty much the same thing as testing a tire for leaks with soapy water, only in your case it's the cylinders leaking (and not a tire) and the liquid is diesel fuel (and not soapy water). I'd say pull the plugs and clean their threads and the holes in the heads and reinstall them and see if the bubbling stops.

 

[jlwoods99]

I Wasn't sure if it was just the fluid boiling off, after I primed the fuel system I had fuel laying everywhere so thought perhaps it wasn't a leak as much as boiling off. I saw a good youtube video on changing brushes and voltage reg on the back of a alternator.

jim

 

[LCAM-01XA]

Well if it happens on a cold engine you know it's compression leak and not boil-off as at that point the engine simply is not yet hot enough to boil any fuel off.

I've never seen a new regulator like yours sold without the brushes attached to it already, they are soldered to it so you get and install the whole thing as a package. You can buy separate brushes and solder them on your old regulator, but since your VR seems to be cooky might as well replace the whole deal in one shot.

 

[Burg460]

I had a Bronco back in the day and it had a volts gauge along with a battery light. It did the same thing your describing, volts was fine but battery light was on. Within 2 weeks the alt died. I would pull the alt and have it tested. When VR's go bad they can pump A/C current into your batteries and ruin them sometimes over time or it can happen very quickly. So a simple 100 dollar alternator can turn into a replace battery(s) shortly after doubling or tripling the price. Just my .02 cents..