Ford pickup electrical problem, mouse induced?

As in a previous post, I'm still having mouse problems. Short of setting the truck on fire, I'm still not sure how to get rid of the little suckers. But now I have to figure out what my electrical problem is, and wethere it's mouse induced, or a normal malfunction. Symptoms: A fully charged battery goes almost dead over night. Just enough juice in it to turn the engine lights, etc on. And yes I did try a different battery that i know is good, and besides the one that was in the truck is only a couple years old. And when I do manage to get it running with a good battery, the voltage gage reads low, but the longer I drive it, the higher it gets. It started at 8 volts(?) and worked its way upto 12 eventually. Please tell me that this is a normal voltage regulator problem that can be fixed easily. Cuz the thought of trying to find a chewed wire that is shorting out someplace could turn out to be a nightmare and all but make the truck useless. Thanks for ur help,,, and please side step the comments,,, that's what u get for owning a ford, etc

Reply to
Pckstude
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Get a mean cat.

But now I have to figure out what my electrical

Clearly you have something draining juice from the battery while the vehicle is off. Next time you park it overnight, disconnect one of the battery cables. If the battery still goes flat, you have a bad battery. If it stays good, then you have a wiring fault, which may or may not be mouse-related.

It should be going up to about 14.2 volts, for an electrical system in good working order. A fully-charged 12 volt battery is actually 12.6 volts, and the sytem normally runs a volt or so higher in order to charge the battery. Based on that pattern of 8 slowly increasing to 12 volts, I'd suspect a dead cell in the battery.

Please

Just use normal troubleshooting procedure. Disconnecting the battery overnight will tell you if it's a bad battery or an electrical system fault. You could also have a load test done on the battery once it's charged up. Get it done for free at any FLAPS.

If it turns out that you do have a short to ground in the truck, or you think there may be one:

  1. Put a low-reading ammeter in series between a battery terminal and its cable. The 0-10 amps function on a multimeter should suffice. We can assume the short to ground is NOT on any circuit exclusively controlled by a switch, or it would not run the battery down while the truck is off-duty. Dome lights, cargo lights, underhood light, glove box lights, etc. should pull from 0.25 to 2-3 amps, depending on the size and number of bulbs involved. The ECM and radio memory will pull milliamps at most, and your meter probably won't register that little on the 0-10 amp scale.

Say you find 0.75 amps being drawn when the truck is supposedly off. What then? First, look for lights on that shouldn't be on. Glove box, console bin, dome lamps. If no lamps are lit, start taking fuses out of the fuse panel, one by one. If there is no change in the current drain, replace them at once. If pulling a fuse causes the current drain to go to zero, make note of what circuit it controls. That should be marked on the fuse panel cover, or be in the owner's manual. You may find one or more fuses that will cause a very slight drop in current drain when removed. Chances are they supply "permissible" drains, like radio memory, clock, and ECM, or alarm if fitted.

If you have isolated the problem to one circuit, give all the visible wiring a good visual check and look for signs of mouse gnawing. If they've gotten through to the copper, it should be visible. If no visible damage can be found, try working your way through the affected circuit, preferably in a consistent direction, either source to load, or load to source. Pick one and stay with it. I know this can be tough, as wire harnesses are designed to be easy to manufacture, not easy to troubleshoot. And I know some vehicles now have multiplexed electrical systems, where a digital code is sent from the ECM to turn on a device that is constantly connected to a power source. My best suggestion here is to simply unplug, one by, each device on a cicuit controlled by the fuse which appears to host the power drain, and see what happens.

Another clue may be: are there any electrical accessories that used to work, and now don't?

Gord Richmond

Reply to
Gordon Richmond

its a ford. I won LOTS of money on ford electrical systems.. but, pull the POSITIVE post..off the battery,,,is it clean AND black/darker than the negative.. CLEAN IT..sometimes you must take a file to this to cut the black oxide that forms.. IF it IS black, the battery never gets fully charged.. check the date on the battery, 3 years is suspect, do as suggested take to flap and charge/load test.. if its VERY new, do this as well..

FIRST suspect is a CLOCK.. IF its stuck trying to 'wind itself' its a good draw on the battery.. find that fuse first and pull it..probably a 5 or 10 amp..

--Shiva--

Reply to
me

and this would show quickly by once its running, measuring the output voltage of the alternator IF this has a mechanical regulator, a stuck set of points would ALSO do this, but by then I would suspect the alternator is also fried, and needs replacing that makes IIRR about a 3-4 amp load on the system..

--Shiva--

Reply to
me

It's fixed! The altenator tested bad at the shop I took it to, and the guy there said that it was probably a diode. So I bought an altenator from the good man and installed it. Upon starting it the volt gage went right where it should be. Thank goodness that it was a simple fix. So thank you gentlemen for all your good advice, some of which I am going to save for future reference. Just goes to show that life is a continuious learning process.

Reply to
Pckstude

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