Chasin' an electrical problem
Thread Starter
|
Junior User
Joined: Oct 2005
Posts: 50
Likes: 0
Chasin' an electrical problem
I got a '94 F150 that won't hold a charge for more than a few days, less when the temp gets down as far as it does in MN, understandably. I don't drive it everyday, but it never used to have a problem even for a few weeks at atime of not drivin. The battery is new and I had the alt. tested and its ok too.
I obviously have a drain somewhere that I need to track down. As of right now I am just pullin fuses and checkin it every couple days to see if has got juice. My ? is what can I use to find where the power is draining?
I recently put new body mounts in it, which required jacking up the body from the frame. I am wondering if something got pinched during that process, but everything seems to be working fine and I was very careful during that process. I also installed a new radio a few months ago, and as you can probibly tell, I am not the best with wiring, but that seems fine too. I got the radio fuse out right now so if it starts tomorrow, thats my culprit.
Any advise with finding an electrical drain would help, including the types of testers I would need to find it.
I obviously have a drain somewhere that I need to track down. As of right now I am just pullin fuses and checkin it every couple days to see if has got juice. My ? is what can I use to find where the power is draining?
I recently put new body mounts in it, which required jacking up the body from the frame. I am wondering if something got pinched during that process, but everything seems to be working fine and I was very careful during that process. I also installed a new radio a few months ago, and as you can probibly tell, I am not the best with wiring, but that seems fine too. I got the radio fuse out right now so if it starts tomorrow, thats my culprit.
Any advise with finding an electrical drain would help, including the types of testers I would need to find it.
Fleet Mechanic
Joined: Sep 2003
Posts: 1,279
Likes: 1
From: savannah,ga
you need a volt meter
analog or digital
pull the pos. battery cable
one wire to bat and one to the cable
do not turn on any loads
if there is a drain you will see 12 volts on the meter
pull the radio or fuse first to stop the continuos memory drain
pull one fuse at a time
the circuit that is drianing the batterywill drop the voltage
reading when unplugged
analog or digital
pull the pos. battery cable
one wire to bat and one to the cable
do not turn on any loads
if there is a drain you will see 12 volts on the meter
pull the radio or fuse first to stop the continuos memory drain
pull one fuse at a time
the circuit that is drianing the batterywill drop the voltage
reading when unplugged
Senior User
Joined: Oct 2005
Posts: 446
Likes: 1
From: Germany
Used to track down shorted wiring with a compass. Not sure what the new technology (ECM, etc) would do though. Don't discount your starter though. They can short out and still work fine for a while.
Good Luck.
Good Luck.
Posting Guru
Joined: Jan 2002
Posts: 1,346
Likes: 8
From: Baltimore
You can purchase a decent digital multimeter at Radio Shack for around $40.00. You want one that can measure at least 10 amps.
Disconnect the negative battery cable. Set the meter to measure DC amps at the highest scale if the meter doesn't auto range. Insert the probes into the meter to read amps.
Place the black meter lead on the negative battery post and the Red lead on the negative battery cable. Make sure the inside cab lights are out so you're not measuring the current draw with them on. Also remove the underhood light bulb if you have that option.
The meter leads complete the circuit and you can now measure the current draw from the battery.
The reading should be less than 50 milliamps which is the same as (.05 amps). If the reading is higher, you need to start pulling fuses or disconnecting the fusible links to find the problem. I think most of the fusible links are on the starter solenoid which is mounted on the passengerside fender well area.
You can also disconnect the wire for any device that gets 12 volts direct from the battery like the alternator and starter motor.
Disconnect the negative battery cable. Set the meter to measure DC amps at the highest scale if the meter doesn't auto range. Insert the probes into the meter to read amps.
Place the black meter lead on the negative battery post and the Red lead on the negative battery cable. Make sure the inside cab lights are out so you're not measuring the current draw with them on. Also remove the underhood light bulb if you have that option.
The meter leads complete the circuit and you can now measure the current draw from the battery.
The reading should be less than 50 milliamps which is the same as (.05 amps). If the reading is higher, you need to start pulling fuses or disconnecting the fusible links to find the problem. I think most of the fusible links are on the starter solenoid which is mounted on the passengerside fender well area.
You can also disconnect the wire for any device that gets 12 volts direct from the battery like the alternator and starter motor.
Last edited by F150xlt; Jan 30, 2007 at 11:34 PM.
Thread Starter
|
Junior User
Joined: Oct 2005
Posts: 50
Likes: 0
Thank you all for the advise. I will get out there and check it out the next time it getts above zero degrees, which will probibly be around May!
I checked it a few minutes ago and it was deader than a mackeral. But it is also -10 outside today for the high, so I don't blame it. So I don't think its my radio.
Lumpy, why would my heater core be leaky? I have noticed a very slight drip coming from the front of the engine lately. It is just a drop or two every minute or so, not enough to even notice it in the coolant level. But what would that have to do with an electrical drain?
I checked it a few minutes ago and it was deader than a mackeral. But it is also -10 outside today for the high, so I don't blame it. So I don't think its my radio.
Lumpy, why would my heater core be leaky? I have noticed a very slight drip coming from the front of the engine lately. It is just a drop or two every minute or so, not enough to even notice it in the coolant level. But what would that have to do with an electrical drain?
Senior User
Joined: Jun 2004
Posts: 291
Likes: 0
A bad ground can cause your coolant to become corrosive. Electrolysis or something like that. The heater core is most vulnerable.
I only recently heard about this as well. I used to replace the heater core every other year until I replaced the ground wire from the block. Not to mention being stranded at the supermarket a couple times only to have it start right up an hour later.
I only recently heard about this as well. I used to replace the heater core every other year until I replaced the ground wire from the block. Not to mention being stranded at the supermarket a couple times only to have it start right up an hour later.
Trending Topics
Elder User
Joined: Nov 2005
Posts: 834
Likes: 0
Measuring the amps as F150xlt outlined is the right way to chase the drain. Measuring volts won't get you there. There is always a small amp draw for keeping the memory in the computer and the radio. This small draw will always show voltage. If you measure the amps you can tell the difference between a normal draw and one large enough to drain the battery. Follow those directions carefully to not over load the meter or probe wires. Most meters are fused internally. Might be a good idea to pick up a spare fuse when you get the meter, if you have a spare you won't oooops and blow the fuse.
When you said the battery won't hold a charge, we are assuming the battery is good, and it is being fully charged. This is different than truck won't turn over. If the good battery is really going dead when sitting, a bad ground is not your problem this time. Bad ground could prevent it from starting, or from charging the battery properly, but it won't drain a charged battery.
Cold weather sucks, really cold weather really sucks. Hi here today maybe 15.
Good luck Frank
When you said the battery won't hold a charge, we are assuming the battery is good, and it is being fully charged. This is different than truck won't turn over. If the good battery is really going dead when sitting, a bad ground is not your problem this time. Bad ground could prevent it from starting, or from charging the battery properly, but it won't drain a charged battery.
Cold weather sucks, really cold weather really sucks. Hi here today maybe 15.
Good luck Frank
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Junior User
Joined: Oct 2005
Posts: 50
Likes: 0
Another "thank you" goes out to all of yous. It's just getting colder outside( woke up to -18 air temp. this morn.), but its nice to know that once it does warm up out there I'll have the knowledge to find this problem. Its also nice knowing I'm heading for Vegas/L.A. next week, where it will hopefully be a little warmer!Thanks again.