1993 5.0 Voltage Drop
05-31-2015, 02:31 PM
#1
1993 5.0 Voltage Drop
Hello all,
My 1993 F-150 is better than ever. Two new fuel pumps, a new starter and solenoid, and new fluids. But I have noticed that after the truck has been running awhile at normal operating temperature, the battery voltage gauge will subtly change from about the A to the M and stay constant. I know, its still in the NORMAL on the gauge, but just curious.
Also, it would sometimes dip to the R at a light with nothing but the blower on, but after the starter went bad and the solenoid was changed too, it only does it when stopped and in gear when the lights AND blower are on. Is this normal?
New battery, cleaned cables. 84,000 original miles.
Also, just wondering: what letter does your truck's temp gauge stay on at normal operating temperatures? Mine fluctuates, but only between the N to R range.
My 1993 F-150 is better than ever. Two new fuel pumps, a new starter and solenoid, and new fluids. But I have noticed that after the truck has been running awhile at normal operating temperature, the battery voltage gauge will subtly change from about the A to the M and stay constant. I know, its still in the NORMAL on the gauge, but just curious.
Also, it would sometimes dip to the R at a light with nothing but the blower on, but after the starter went bad and the solenoid was changed too, it only does it when stopped and in gear when the lights AND blower are on. Is this normal?
New battery, cleaned cables. 84,000 original miles.
Also, just wondering: what letter does your truck's temp gauge stay on at normal operating temperatures? Mine fluctuates, but only between the N to R range.
Last edited by bus12; 05-31-2015 at 02:36 PM.
05-31-2015, 02:48 PM
#2
That gauge basically tells you how much juice the alternator is pumping to keep up with everything and keep the battery charged. The lower it goes, the less the alt. is putting out.
Get a cheapy voltmeter, set it to 20 volts DC, and put the ends to the 2 posts on your battery. Key off, 12 to 13 is good, running you should see 14 - 14.5. Test with everything off and then with lights and blower on.
Your alternator or battery could be getting weak.
For a baseline, mine never moves and everything is working good.
My temp gauge warms up to the R and never moves - but that's just an electrical sending unit, not really accurate but if it suddenly spikes over to the A or L you probably have an issue and should pull over.
Get a cheapy voltmeter, set it to 20 volts DC, and put the ends to the 2 posts on your battery. Key off, 12 to 13 is good, running you should see 14 - 14.5. Test with everything off and then with lights and blower on.
Your alternator or battery could be getting weak.
For a baseline, mine never moves and everything is working good.
My temp gauge warms up to the R and never moves - but that's just an electrical sending unit, not really accurate but if it suddenly spikes over to the A or L you probably have an issue and should pull over.