If you've ever had a slow power drain, HELP!

99FiveOh · Feb 14, 2009

I just bought this car a couple weeks ago and some mornings it starts right up, and other mornings it'll be "click, click, click" battery dead! So I jump it off and go to work and it always starts up 8-10 hours later when I get off. The terminals look good and my alternator is charging, however, it is making alot of racket lately and sometimes I can hear it through the radio. Also, when I come to a stop light, the power gauge does go way down and I can hear the alternator even more! And the lights get really dim.

When I got the car it had no radio installed, but still had the problem, So I've ruled that out even though I have one now. The Mach 460 amps won't kick on unless they get power from the radio to turn them on, much like an aftermarket one does. I can hear them turn off when I shut the radio off.

How did any of your fix your slow draw/drain problems? What turned out to be the culprit? I have a few days off in a row coming up and I wanna nip this in the bud! I appreciate any advice!

HISSIN50 · Feb 14, 2009

Have you done a parasitic draw test to see how bad of a drain you have? Sometimes that gives a clue where to start removing fuses (a bigger draw with low alt output can be a bad alternator, for instance). You'll need to pull out the meter to narrow down the source of the draw anyhow.

In general, all of your little switched lighting (glovebox, trunk, underhood, etc) can be problematic.

Good luck.

99FiveOh · Feb 14, 2009

Hissin, just the guy I wanted to hear from! Can a bad alternator cause a draw while the car is off? Like a shorted out diode causing a very weak, but steady short all night long, sometimes worse than other times?

With a regular volt meter, how can I test this? Or do I have to have one that measure DC amps? thanks for the help!

HISSIN50 · Feb 14, 2009

The alt can indeed cause a draw (when a diode goes south). This can also cause a lack of total output under demand.

Close the doors and turn everything off (remove the underhood light bulb if needed). Disconnect the negative battery connection. Put one meter lead on the post and one on the cable. Set your meter to read current (normally most meters have a small current scale, like 10 A. Be sure to not overload the meter. All the current for the car is now going through the meter).

You should see a reading on your meter (.100 A, for instance). Start pulling interior fuses one at a time (once tested, disable the interior light circuit) till the reading drops. Once it drops, that last fuse pulled has a drain. If no fuses cause the reading to drop, pull the underhood fuses. To test the alt, depending upon any wiring mods, you might have to disconnect the charge cable from the alt (or PDC). If your reading drops, have the alt bench tested. They should be able to pick up a bad diode.

In case it helps, here's a little article:

Battery Service

Good luck.

Oh yeah, you won't get a zero reading, but if under like 25 mA or so, you should not have issues. The EEC, radio presets, etc ue a tiny bit of memory.

99FiveOh · Feb 14, 2009

Well, the alternator is the object of interest as of right now, so I'll rebuild it and see what happens. It definately lets the light get super dim and I've noticed the battery is dead the next day when I've driven the car at night the night before. When I take it to work, I go during the day and she starts right up when I get off. Plus with it making the loud whining noise it is, and hearing that noise through my stereo speakers, it needs to be replaced/rebuilt anyway.

Zero_chance · Feb 15, 2009

You could have a bad alternator thats barely charging the battery, and when it sits overnight, the litle bit of normal draw is finishing it off. Especially if you live in a cold climate, the battery really needs to be up to snuff. As for doing the draw test , its always a good idea to have the door switches depressed or disabled for theyll ruin your test if you open the door. Generally supposed to wait around thirty mintues for modules to go asleep though our cars have consdierably fewer modules than new ones. Try performing this test on a 08 Lincoln Navigator (well over a dozen modules), the vehicle was already setup for the test and then a young kid in the shop went and tugged on the handle of one of the open doors, which triggered to latch to pop open setting off the door ajar switch. Needless to say, a lot of time down the drain.

Back on topic, have you had your battery and alternator tested??

99FiveOh · Feb 15, 2009

The battery is brand new, the guy installed it when I picked up the car. The alt doesn't really need testing, it's making alot of noise so I know it's on the way out anyway.

95Vert383AOD · Feb 16, 2009

Wow im having alot of the same issues. I will try some of this stuff as well. I don't want to start another Battery/ Charging discussion because theres already a million (Excuse the thread jacking) ....

Soooo...i have a full after market stereo...2 Amplifiers under where the back seat is with a total of roughly 1500 watts RMS. My battery is relocated with a 1Ga charge back wire. To save some wire i interrupted the charge back wire to connect the amps using a distribution block. Is this bad? I have noticed the car running will have the voltage gauge dead in the middle....when the stereo goes on the voltage drops severely with every beat. Should i connect the charge back wire directly to the battery (No interruption) and then jump it the 2 amps off of that? I'm using a 200amp alternator and a Odyssey 2150 Battery. All chargeback wires are connected using copper ring terminals Soldered (with flux and blow torch like copper plumbing pipe)

Once again excuse me for the lengthly thread jack. Let me know if this should be moved to yet a new thread.

Chris

Zero_chance · Feb 16, 2009

For your stereo system you should definitely have a capacitor to stop the power from being drained with every beat, puts a lot of stress on the alternator. Capacitors store power then use it to feed the stereo during peak output.

Back to the original owner of the post, it seems like you should get your alternator replaced or rebuilt by a reliable source then see if the problem still exists. Trying to diag a problem with known bad components can lead to a lot of wasted time and tail chasing.

HISSIN50 · Feb 16, 2009

Zero_chance said:
Back to the original owner of the post, it seems like you should get your alternator replaced or rebuilt by a reliable source then see if the problem still exists. Trying to diag a problem with known bad components can lead to a lot of wasted time and tail chasing.

I seem to have some faint recollection that he used to rebuild alternators professionally.

Zero_chance · Feb 16, 2009

That would solve the reliable part then.

99FiveOh · Feb 16, 2009

LOL! Yes, I can rebuild it. I'm waiting on a new rectifier, stator, HD regulator and brush holder to arrive. I'm going to build a 200 amp unit to take care of any future plans.

95Vert383AOD · Feb 17, 2009

The_Mustang said:
LOL! Yes, I can rebuild it. I'm waiting on a new rectifier, stator, HD regulator and brush holder to arrive. I'm going to build a 200 amp unit to take care of any future plans.

Hey where do you get the 200amp parts? I have a friend that can rebuild it but i dont know where to find the upgraded parts. Thanks

99FiveOh · Feb 17, 2009

I have an account with a wholesale parts supplier. They don't sell to the general public. I got my account long ago and can still order on it when I need. If you need parts, you can go through me and I can have them drop ship it to you. PM me with what you need and we'll go from there.

On topic, I'll be rebuilding the alternator tomarrow with parts I have laying around to see if that fixes it.

HISSIN50 · Feb 17, 2009

HISSIN50 · Feb 17, 2009

Fordfuelinjection has parts for a 200 amp build as well.

Otherwise, googling Transpo might reveal some info

99FiveOh · Feb 19, 2009

Just got through tearing the alternator apart and there were two diodes that were liquified. Crappy transpo junk! Looks like this alt was replaced not too long ago by the last owner, everything inside looked new and def. wasn't Ford issue.

It amazes me how Ford puts stuff on cars and it lasts years, sometimes decades... but most aftermarket crap won't even last a couple years. I'm going to throw an old original stator/rectifier assy. in there for now until I get ready to upgrade it to 200 amps.

99FiveOh · Feb 19, 2009

Everything is working great now! Not sure if the power drain was related, but I'll soon find out. I went for a drive with the lights on and everything else running too, and the volt gauge didn't budge! I'm pretty sure it's fixed now.

Still getting feedback from the charging system on my radio. Any suggestions how to fix this?

fordtech28 · Feb 20, 2009

The_Mustang said:
Everything is working great now! Not sure if the power drain was related, but I'll soon find out. I went for a drive with the lights on and everything else running too, and the volt gauge didn't budge! I'm pretty sure it's fixed now.

Still getting feedback from the charging system on my radio. Any suggestions how to fix this?

For the feedback check the grounds on the radio also theres a "filter" next to the coil that controls radio feedback I seen those go back too.If it all checks out you can purchase a radio filter from any electronics store it goes inline with the power and the ground to eliminate feedback

95Vert383AOD · Feb 20, 2009

fordtech28 said:
For the feedback check the grounds on the radio also theres a "filter" next to the coil that controls radio feedback I seen those go back too.If it all checks out you can purchase a radio filter from any electronics store it goes inline with the power and the ground to eliminate feedback

My charging system is happy now as well....I rewired and now i have zero feedback. If your battery is in the trunk the ground cable should be no longer than 2-3ft. Shorter the better. Ground should be the same thickness as the positive. If the battery is still up front check the ground connections. if they look questionable.....unbolt them off the radiator support, sand the ground terminals and the spot of the radiator support where they connect. check the ground on the block right next to the oil filter. Sand terminal/ spot on the block where it bolts. If you have an aftermarket radio....sand off hole in the sheet metal behind the dash and ground the radio there. (don't use the factory radio ground)

I have had many aftermarket radios in many fox body cars. Its ALWAYS the ground....your ground connections need to be clean enough to eat off. Ground wire from the battery to the chassis should be as short as possible and the same size as the power wire. i believe ford only uses 1 thick ground wire for the block. Making your own short ground strap from the battery straight to the radiator support of 2-4ga should fix this.

I Run a Jvc radio 2 Amplifiers 0Ga. wire to relocated battery in the trunk. and no feedback. I eat off my ground straps ....

Oh and Dielectric Grease doesn't hurt!!!
I hate those filters. They're just bandaids. Fix the ground.

If you've ever had a slow power drain, HELP!

99FiveOh

HISSIN50

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99FiveOh

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