Hey guys, I have a 95 bronco and shes running great now. Well I drive an hour down to school and an hour back home, and its about 75% Highway and 25% City, well its been cold so i had my heater on, rear window defroster on, radio and of course my lights, on low beam. Well i came to a light and i stopped well i looked at my volt guage and it dove way down. Truck didnt stumble or anything i didnt notice my lights dim its just the needle went to the O on NORMAL. As soon as i took off it was back to normal. So i turned my rear deforst off and it was ok when i came to the next light. Turned it back on and stopped and it was back down to O. Soo.... Does this mean i have an alternator going... Or is that normal for the rear defrost to suck that much juice? Also when i start it up in the morning it sounds like my fan is hitting the shrowd, but its not it sounds like its coming from the alternator. And when i take off there is a high pitched whinding noise. I know its cold outside and once it warms up it goes away, but i just dont want the alt failing when im an hour away from home in the city. Well hopefully you guys can help me out. Are there any tricks of telling if its bad or not? Thanks alot guys!

 

Put a volt meter on the battery while its running. I dont think its bad just because it goes down at idle with everything on. When you say the o in normal, I'm not sure what you mean. My 90' has volts in numbers. Its not real acurate, but its in numbers. My temp and oil guage say normal. I'm not sure about an 95'. The sound could be from the smog pump. Mine use to do that.

 

Mine is the word NORMAL, usually stays between M and A but untill i discovered the rear defrost. Il do that and tell what i get.

 

I went outside and while the truck was runing i had 14.6 Volts. Seams pretty low to me. Shouldnt it be up towards 15V?

 

14.6 V sounds great to me

 

If your fanbelt is OK then take your fanbelt off and turn the pulley on your alternator and see does it turn freely or grind or stiff, if it's OK then check the idler pulley for the fanbelt they do go bad quite often see if it's seized or stiff or perhaps just wonky because of a bad or worn out bearing.
Also check your fan itself to see if its bent or damaged ie.. cracked or broken.

If all these things are OK then start by checking your battery and Cables, alot of folks think battery cables last forever(They Don't) and will replace battery and alternators by the boat load while never fixing the problem.



GL, Rick.

 

Thanks rick, fanbelt is new along with the Idler pully. Il look into everything else that youve mentioned this weekend when it gets warmer. Im gonna look into a 3G alt. I dont know why ford used such a dinky alt on these trucks!

 

Do you have a thermostatic fan clutch or is it a constant slip type? There is silicone
fluid in there and if it's shot or leaked out or stiff from cold, it won't spin out and do
what it is supposed to until it gets up to temp. If it's non thermo I say junk it since
the constant slip don't help when you are overheating since they stay at a constant
60% slip when you need it to be at 95% at least of the rpms!! You should add a real
\voltmeter that is accurate the combo of amp and voltage will give a better idea of
what is happening. Making your own led voltage is pretty easy.

 

I converted my fan to electric.

 

I had some horrible noise when I would first start mine
and it turned out to be the AIR pump. I have also already
done a 3G upgrade and its so nice to look down with everything
on even at idle sitting at traffic light 14 to 14.5. She works
Gooooood. I got a 130A for a 94 Mustang. If I can be of any
help if you do this just look me up.

 

my truck does this to and i run an e fan constantly, i wouldn't worry too much about it, if you want to though you can putt all the accesories on in the car and start it up and put an amp clamp around i BELIEVE the + cables and see how many amps ur drawing, like i saidi believe the + its been a while since i've done this..good luck

 

Seeings your talking amps and volts, how would you run the amp gauge?

 

To above; Don't you already have a ammeter on your stock cluster?

 

I have never trusted anything in the factory clusters.
For example, what does an oil pressure gauge tell me
when it is between the R and M, What is the real temp,
when it is between the M and A, that one I can tell you,
Its getting rather hot but know this only because I put in
a mechanical gauge.
Most are just switches.
I wouls have not really noticed or known that it was
charging at 12.5 rather than 14.5 in just the distance between
the O and R instead of M and A.
Try explaining when a mechanic asks you what temp you are running at
and tell him somewhere between O and M, thats real informative.
I just thought you nad a specific way or another way than I do.