Electrical problems in truck. Now what???

[namesray]

I bought a f 350 dump truck last year. Its a 2003 with 6.0 diesel. Has 135000 miles. Engine has delete kit and stud kit done. After I had the crank position sensor fixed, it ran great all last year. Over the winter it developed some electrical issues. First the battery would drain. I put a trickle charger on it. That dealt with the problem. Next it wouldn't send power to the starter when the key switch was turned but would start if selinoid was crossed at starter. The exciter wire connection was corroded. I cleaned and this fixed that problem. I wanred to fix the parasitic drain on battery. This was above me so went to a garage. Long story short, they can't find the problem and it has developed new problems, such as lights not shutting off with switch or even when corresponding fuse was pulled. A new fuse box did not fix the problem.

So now I have a truck that drains the batteries, takes forever to jump start, the lights have a mind of their own and mechanics can't find the problem. They were not a Ford garage, but the local Ford garages couldn't find the crank position sensor issue when I first bought truck. So I don't have much faith in the local Ford garages.

I feel lost and have no idea what would be a wise decision. I pretty much have a big investment in a piece of junk nobody would want to buy if I tried selling it. Worried taking it to other garages is going to end up a wild expensive goose chase that never finds the problem.

Anybody have any ideas or suggestions. I would greatly appreciate them even if its just decision advice. I am at a loss of thinking on my end. Thanks.

 

[1stDeuce]

Ahhh, I don't miss living where road salt is used all winter. Sounds like there are very likely more corrosion issues elsewhere in the wiring. Negative wiring usually doesn't corrode, so start by looking at all things that get positive 12v power.

I would disconnect EVERY connector outside the cab and inspect. If it looks good, add some dielectric grease and re-assemble. If suspect, clean as good as you can, replace any really nasty green pins if necessary, and again, dielectric on everything. If you find water inside a sealed connector, blow it out, clean it out, and then use LOTS of dielectric grease. Sometimes just plugging/unplugging several times after adding some dielectric grease will resolve contact issues and prevent them from re-occurring.

If you want not to spend a lot of money, this is something that's easy to do yourself. Just take your time and go through everything. Spray stubborn connectors with WD40 if they don't want to unplug easily.

For the continuous draw, turn the key off, disconnect the negative battery cable and put a decent multimeter in the circuit. Set it to monitor amp draw on a 10A scale. How much draw you see should correspond to how quickly it runs down. A 1A draw will run a normal truck sized battery dead in a few days. 0.25A might take a week. Most new vehicles have ~0.1A of draw all the time, and can't be left to sit unstarted for long periods of time like older vehicles. If you're under .1A, then your problem is either intermittent, and harder to find, or you've got a battery with a partially shorted cell. If there's a draw, start pulling fuses one at a time, checking to see if the amp draw goes away after each one. When it drops to near zero, you at least know what circuit is causing the draw.
If the draw is really low, disconnect the battery and let it sit. If it's dead the next time you hook it up, you need a new battery...

I should also say that if there's any aftermarket accessory that was wired in along the truck's life, you should immediately suspect it as the draw... If you see non-factory wiring at the battery or fuse box, disconnect that first and see if the problem goes away.

And I'll add that batteries do not like to be run to zero volts. If it's gone flat a few times, it's not going to hold much of a charge, and you will need to replace it. If you can't get the draw fixed before you put in a new battery, put in a disconnect at the same time, and disconnect the battery when you're done using the truck. At least that way you won't have to buy a new battery again... I've found that this style disconnect is cheap, easy to install, and easy to use. I would suggest putting it on the negative side, so you don't have to worry about anything metal touching it and arcing out to ground. Once you solve the problem, you can remove it.

Good Luck!!

 

[rustydollar]

A friend of mine recently had his new car towed into the dealership to have the wiring replaced, dealer told him the new plastic used to insulate the wiring on new vehicles is soy based and the Asian roof rat has added this to his diet.

The dealer is having the same problem with new cars on the lot, the rat from Asia is costing them hundreds of thousands of dollars to keep ahead of the invasion from China.

These Asian roof rats have hitch hiked a ride from Asia on cargo ships entering the Canadian port in Vancouver, you fellows south of the 49th have the same problem.


PROTECT YOUR CAR: Rodents eating wires in newer vehicles | WSB-TV

 

[Egon]

For unknown battery draw you might try pulling one fuse at a time in hopes of isolating the bad circuit.

 

[Stimw]

I had a low draw problem so I pulled the battery cable off, put a test light from cable to post and pulled fuses until I found the problem/light went out.
I had passenger seat switch problem. I cycled it a few times and haven't had a problem since.

 

[KYErik]

I have seen a battery cable clamp that has a heavy duty switch built in- that would be a temporary fix for the parasitic drain issue. Your headlight issue might be a relay that is sticking closed- but the switched battery cable clamp would sort of take care of that too (if you don't mind driving everywhere with your lights on).

 

[namesray]

Thanks everyone. To tell you the truth, looking at this 6.0 diesel engine compartment is very daunting to me. I really wouldn't know where to begin. When I get it back home, I will try to check connections but you would think the garage would have done that as an easy way to dismiss problem areas.

There is a snow plow, and a brake controller was added last summer. The block heater cord was also worked on. Maybe I will double check these areas. Is there any way they could mess with the lights not shutting off even when fuse is pulled?

I could "deal" with the parasitic draw and I like the shut off/kill switch idea. But the lights having a mind of their own worries me. I am concerned about a fire risk. Or if they quit working all together when I need them. Where could the problem be if the lights still stay on after fuse is pulled? Seems like this could be a clue where to narrow down the problem area?

About a "relay sticking" causing lights to stay on , where would I even look? Maybe I talk with the garage about this. Thanks for some sence of direction here. I will keep you posted.

 

[Sysop]

I feel your pain in sorting out a vehicle wiring issue. Wiring only, I can handle. Mechanical only, I can handle. Start mixing the two, it gets intimidating fast.

If you area is like mine, there are lots of mechanic shops, but not all have good diagnostic techs and the ones that do, only specialize in certain things. Out of probably 50 shops in my tiny town, only one is good at electric diagnosis, only one is good with locating AC leaks, only one is good at getting a leaky sunroof repaired, etc.... You just have to find the right shop with the right diagnostic tech.

 

[rustydollar]

Thanks everyone. To tell you the truth, looking at this 6.0 diesel engine compartment is very daunting to me. I really wouldn't know where to begin. When I get it back home, I will try to check connections but you would think the garage would have done that as an easy way to dismiss problem areas.

There is a snow plow, and a brake controller was added last summer. The block heater cord was also worked on. Maybe I will double check these areas. Is there any way they could mess with the lights not shutting off even when fuse is pulled?

I could "deal" with the parasitic draw and I like the shut off/kill switch idea. But the lights having a mind of their own worries me. I am concerned about a fire risk. Or if they quit working all together when I need them. Where could the problem be if the lights still stay on after fuse is pulled? Seems like this could be a clue where to narrow down the problem area?

About a "relay sticking" causing lights to stay on , where would I even look? Maybe I talk with the garage about this. Thanks for some sence of direction here. I will keep you posted.

Lights staying on after the fuse is pulled would indicate a short inside the wiring harness where power and service wires run parallel to each other inside the harness. Rodents.

If you did not have the problem with the lights coming on with a mind of their own I would have suspected a bad alternator diode in the rectifier pack which contains three positive and three negative diodes to convert three phase AC current into DC.

Most common failure with alternator diodes is from boosting the vehicle to start it or giving a boost to another.

 

[aczlan]

There is a snow plow, and a brake controller was added last summer. The block heater cord was also worked on. Maybe I will double check these areas.

I would bet on the problem being with the snow plow light controller. That is what is used to switch from your normal headlights to the headlights on the plow headgear and on the plow trucks I used to work on when I worked for a landscaper, those control boxes were notorious for shorting out and having a draw that just kept going because they had unswitched power as well as the power from the stock headlights.

Aaron Z

 

[RNeumann]

Ahhh, I don't miss living where road salt is used all winter. Sounds like there are very likely more corrosion issues elsewhere in the wiring. Negative wiring usually doesn't corrode, so start by looking at all things that get positive 12v power.

I would disconnect EVERY connector outside the cab and inspect. If it looks good, add some dielectric grease and re-assemble. If suspect, clean as good as you can, replace any really nasty green pins if necessary, and again, dielectric on everything. If you find water inside a sealed connector, blow it out, clean it out, and then use LOTS of dielectric grease. Sometimes just plugging/unplugging several times after adding some dielectric grease will resolve contact issues and prevent them from re-occurring.

If you want not to spend a lot of money, this is something that's easy to do yourself. Just take your time and go through everything. Spray stubborn connectors with WD40 if they don't want to unplug easily.

For the continuous draw, turn the key off, disconnect the negative battery cable and put a decent multimeter in the circuit. Set it to monitor amp draw on a 10A scale. How much draw you see should correspond to how quickly it runs down. A 1A draw will run a normal truck sized battery dead in a few days. 0.25A might take a week. Most new vehicles have ~0.1A of draw all the time, and can't be left to sit unstarted for long periods of time like older vehicles. If you're under .1A, then your problem is either intermittent, and harder to find, or you've got a battery with a partially shorted cell. If there's a draw, start pulling fuses one at a time, checking to see if the amp draw goes away after each one. When it drops to near zero, you at least know what circuit is causing the draw.
If the draw is really low, disconnect the battery and let it sit. If it's dead the next time you hook it up, you need a new battery...

I should also say that if there's any aftermarket accessory that was wired in along the truck's life, you should immediately suspect it as the draw... If you see non-factory wiring at the battery or fuse box, disconnect that first and see if the problem goes away.

And I'll add that batteries do not like to be run to zero volts. If it's gone flat a few times, it's not going to hold much of a charge, and you will need to replace it. If you can't get the draw fixed before you put in a new battery, put in a disconnect at the same time, and disconnect the battery when you're done using the truck. At least that way you won't have to buy a new battery again... I've found that this style disconnect is cheap, easy to install, and easy to use. I would suggest putting it on the negative side, so you don't have to worry about anything metal touching it and arcing out to ground. Once you solve the problem, you can remove it.

Good Luck!!

Here's your answer! Once you see the amps on the meter begin disconnecting every fuse one by one and checking. After the fuses remove to the relays. Next circuit breakers and finally the alternator. The last would be the computer. Think of this, or any other diagnostic situation, methodically. Like head to toe. Battery is the head, fuses are the neck and light bulbs etc are the toes- don't jump around.

 

[TemporaryKubotaOwnerMark]

Here's your answer! Once you see the amps on the meter begin disconnecting every fuse one by one and checking. After the fuses remove to the relays. Next circuit breakers and finally the alternator. The last would be the computer. Think of this, or any other diagnostic situation, methodically. Like head to toe. Battery is the head, fuses are the neck and light bulbs etc are the toes- don't jump around.

Exactly right!

One step at a time, and keep a log keep a log keep a log. Otherwise, you will get lost and confused!

And remember the first rule of automotive electrical problems: When things get weird, check your grounds. Poor grounds cause all kinds of weird stuff that makes no sense. And don't just look at it - take it apart and clean connector and mounting point to bare metal, slap on some dielectric grease (as already mentioned) and only then can you call it good.

You can do this! :thumbsup: It just takes patience.

And keep a log! :drink:

 

[DJ54]

I can't remember which truck it was, but was having the same problem of battery draw down. Pulled it in the shop, after getting it started to do some checking. Pulled the OH door down, but had not yet turned the shop lights on, as I had a light panel in the back wall for some natural light. Light on the passenger side floor caught my attention, as I forgotten my gloves to do another small chore before starting on it. Just so happened, the glove box light was staying on IIRC, due to a faulty switch. Hopefully, it's something that simple.

 

[TractorGuy]

I had a low draw problem so I pulled the battery cable off, put a test light from cable to post and pulled fuses until I found the problem/light went out.
I had passenger seat switch problem. I cycled it a few times and haven't had a problem since.

This is the best way to look for a battery drain. If it has enough current draw to light an incandescent 12v test light it has enough draw to kill the battery. One word of caution: disable the interior light switch while performing this test with the door open. Either tape the switch down or remove it's fuse.

I will echo the need to make sure all grounds are good. Locate all the ground connections you can, loosen, spray with WD40, and re tighten.

These things can drive you nuts. My 2003 F150 started locking itself randomly and that went on for 3 years. Finally I found a thread saying this was caused by a bad battery. My 9yo battery was still starting the truck just fine but I went ahead and replaced it. BAM, no more door lock problem.

It really helps if you can get a good wiring diagram and know how to interpret it.

 

[namesray]

This is the best way to look for a battery drain. If it has enough current draw to light an incandescent 12v test light it has enough draw to kill the battery. One word of caution: disable the interior light switch while performing this test with the door open. Either tape the switch down or remove it's fuse.

I will echo the need to make sure all grounds are good. Locate all the ground connections you can, loosen, spray with WD40, and re tighten.

These things can drive you nuts. My 2003 F150 started locking itself randomly and that went on for 3 years. Finally I found a thread saying this was caused by a bad battery. My 9yo battery was still starting the truck just fine but I went ahead and replaced it. BAM, no more door lock problem.

It really helps if you can get a good wiring diagram and know how to interpret it.

The batteries have been triple tested (draw test) and both tested great. Even put 2 brand new batteries in for couple days and was having same problems.

Will try to get truck back home from garage this week and start going through it. I won't be fast at this as I am no mechanic, but I like the methodical approach tip. Wish me luck and thanks again. I update back on any progress.

I have no manuel with this truck. Where might I find a wiring diagram or atleast a fuse panel lable refrence. I don't know what every fuse goes to and nothing is labled.

 

[aczlan]

I have no manuel with this truck. Where might I find a wiring diagram or atleast a fuse panel lable refrence. I don't know what every fuse goes to and nothing is labled.

If you look in the owner's manual or download one from online that should have a listing of what each fuse in the fuse panel does. It may not be exact for your truck but it should get you close.

Aaron Z

 

[TractorGuy]

You should be able to register at the Ford Owner site, enter your VIN, and download an owners manual to get the fuse box layout.

Found this link on Google that might help.