New to the forum. Have a slight problem
11-09-2010, 01:06 PM
#1
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New to the forum. Have a slight problem
Hi everyone. I just found this site while trying to search for some issues with my truck.
Its a 91 f150 shortbox 2wd. Single tank 4.9l auto. I have a problem with it losing charge over night. Now the weird part is it only happens when its cold. All summer long i hav no problems. Then in the fall the battery starta dying over night. I have to jump the truck to drive it in the morning and take the negative battery terminal off when i park it. As long as i remember to take off the battery terminal, the battery holds its charge. I replaced the battery and alternator last year. So i assume i have a power draw thats killing the battery. I noticed with the key out of the ignition, when i connect the neg. Battery terminal, the fuel pump comes on momentarily. I can hear the relay click on and off. But it will keep turning back on every time i connect the terminal. I can tap the terminal to the post rapidly, and every time it makes a connection it turns back on. I removed the relay and the pump stays off. But i did hear another click, which sounded like it was coming from either the firewall behind the engine, or down under the engine where the starter motor is. It was a faint click so it was hard to tell exactly where it was coming from. I am not sure if that is the source of the drain,or if its the fuel pump
Issue. but i cant remember any vehicle i have ever owned that would run the fuel pump with the key off. Any ideas of what might be the issue? I thought maybe a short at the ignition switch, but none of the other electronics work with the key out. Any ideas of what i should look for? I am pretty good with anything mechanically, but wiring usually confuses me
Its a 91 f150 shortbox 2wd. Single tank 4.9l auto. I have a problem with it losing charge over night. Now the weird part is it only happens when its cold. All summer long i hav no problems. Then in the fall the battery starta dying over night. I have to jump the truck to drive it in the morning and take the negative battery terminal off when i park it. As long as i remember to take off the battery terminal, the battery holds its charge. I replaced the battery and alternator last year. So i assume i have a power draw thats killing the battery. I noticed with the key out of the ignition, when i connect the neg. Battery terminal, the fuel pump comes on momentarily. I can hear the relay click on and off. But it will keep turning back on every time i connect the terminal. I can tap the terminal to the post rapidly, and every time it makes a connection it turns back on. I removed the relay and the pump stays off. But i did hear another click, which sounded like it was coming from either the firewall behind the engine, or down under the engine where the starter motor is. It was a faint click so it was hard to tell exactly where it was coming from. I am not sure if that is the source of the drain,or if its the fuel pump
Issue. but i cant remember any vehicle i have ever owned that would run the fuel pump with the key off. Any ideas of what might be the issue? I thought maybe a short at the ignition switch, but none of the other electronics work with the key out. Any ideas of what i should look for? I am pretty good with anything mechanically, but wiring usually confuses me
11-09-2010, 01:32 PM
#2
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Put the battery in a police lineup, that's your prime suspect. Batteries do lose power in cooler weather. I know it is better if you remove the negative terminal, but there are power drains that are designed into vehicles for things lije computer memory, radio memory. etc.
Your local auto parts store should be able to test battery for you for free, just to eliminate any doubt...
Your local auto parts store should be able to test battery for you for free, just to eliminate any doubt...
11-09-2010, 03:04 PM
#3
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The Fuel Pump should not be coming on as you described.
Is the Battery you purchased last year a top quality name brand with 600-800 CCA?
A Starter that is going bad can have a continuous electrical draw.
How does the engine run?
Any sputtering?
Hard cranking?
The reason I'm asking is to determine how the Fuel Pump is acting.
-----------------------------------------------------------------------------
My guess is to suspect a weak Battery (Cold weather will tell-on a weak battery)
or
the Starter is going to ground
or
the Fuel Pump is on it's way out.
Then again; it could be one of the taillight wires got chafed and is touching/rubbing the frame near the rear bumper, creating an electrical draw from the battery.
DON'T LAUGH, THIS HAPPENED TO ME ON A 1976 F100 YEARS AGO! lol
Anyone else got anything?
|
Is the Battery you purchased last year a top quality name brand with 600-800 CCA?
A Starter that is going bad can have a continuous electrical draw.
How does the engine run?
Any sputtering?
Hard cranking?
The reason I'm asking is to determine how the Fuel Pump is acting.
-----------------------------------------------------------------------------
My guess is to suspect a weak Battery (Cold weather will tell-on a weak battery)
or
the Starter is going to ground
or
the Fuel Pump is on it's way out.
Then again; it could be one of the taillight wires got chafed and is touching/rubbing the frame near the rear bumper, creating an electrical draw from the battery.
DON'T LAUGH, THIS HAPPENED TO ME ON A 1976 F100 YEARS AGO! lol
Anyone else got anything?
|
Last edited by 1987 F-150 XLT 4x4; 11-09-2010 at 03:36 PM.
11-09-2010, 03:17 PM
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YOU want to perform a parasitic drain <check on your engine using a Volt meter.
.
Make sure that all lights and accessories, and Ignition are off,
check all vehicle doors and make sure Dome lights are off ,
Disconnect the ( - ) battery cable and install a Parasitic load tool , * volt meter *
Start the engine, let to run for bout 5 mins ,be sure to open all the doors , turn on all the lights , raido anything that would draw power, like your heater Rear window !! ,
then after 5 mins turn everything off again , EVERYTHING !
pull the key out connect your volt meter, ammeter , across the parastic load tool and wait for about 5 mins ok, all circuits will shut down ,
Open the switch on the Load tool and read the battery drain on your volt meter.
Normal Voltage for your drain is , 10-30 mA or 0.02 to 0.03 A
Max allowable voltage is 50 mA anything higher then that , and you got a Big problem,
let me know what it comes out too and i can help you Fix your problem , I am a ASE Cirt Electrical tech, we will figure it out ok
..
take care good luck
jayson
.
Make sure that all lights and accessories, and Ignition are off,
check all vehicle doors and make sure Dome lights are off ,
Disconnect the ( - ) battery cable and install a Parasitic load tool , * volt meter *
Start the engine, let to run for bout 5 mins ,be sure to open all the doors , turn on all the lights , raido anything that would draw power, like your heater Rear window !! ,
then after 5 mins turn everything off again , EVERYTHING !
pull the key out connect your volt meter, ammeter , across the parastic load tool and wait for about 5 mins ok, all circuits will shut down ,
Open the switch on the Load tool and read the battery drain on your volt meter.
Normal Voltage for your drain is , 10-30 mA or 0.02 to 0.03 A
Max allowable voltage is 50 mA anything higher then that , and you got a Big problem,
let me know what it comes out too and i can help you Fix your problem , I am a ASE Cirt Electrical tech, we will figure it out ok
..
take care good luck
jayson
11-22-2010, 09:10 PM
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I have the same problem on my 1990. What I was told is my fuel pump relay needs to be played with sometimes to get the engine to start. I say what I was told is my fuel pump relay because it was found in the eec relay spot in the black holder under the hood. Also, when I connect and disconnect my neg terminal I can hear what I bolieve is the fuel pump relay clicking 4 times. The relay that I must shake to get the truck started has a black connector on it, and the one that clicks has a green connector if that helps any.
As I said I have the same problem, not holding a charge over night...... NOT GOOD!
As I said I have the same problem, not holding a charge over night...... NOT GOOD!
11-22-2010, 10:11 PM
#6
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I have the same problem on my 1990. What I was told is my fuel pump relay needs to be played with sometimes to get the engine to start. I say what I was told is my fuel pump relay because it was found in the eec relay spot in the black holder under the hood. Also, when I connect and disconnect my neg terminal I can hear what I bolieve is the fuel pump relay clicking 4 times. The relay that I must shake to get the truck started has a black connector on it, and the one that clicks has a green connector if that helps any. As I said I have the same problem, not holding a charge over night...... NOT GOOD!
As I said I have the same problem, not holding a charge over night...... NOT GOOD!Green is F/P relay.
They are not interchangeable.