Battery Draining 88 T-bird V8 - Help/Advice

I have a 1988 Ford Thunderbird V8 - 2 days ago my batt was drained - wouldn't hold charge bought new one - No issues until tonight when I tried starting and batt was drained - Jumpped it and ran for 5 minutes, shutdown,
restarted fine so batt is charging, ran it for another 5 min and shutdown, disconnecting batt till I can t/s tomorrow. Okay questions - I noticed the day before my batt died the blinkers wouldn't come on all the time which prior never had an issue with - Take note I packed my trunk up full so stuff was pressing against the wires - Could there be a short somewhere in the trunk to cause this??? The Alt, is it possible it is weak and will discharge my batt over a period of time??? I plan to read out wires, check my fuses - Any other pointers before I take the step of replacing my ALT. Can the Alt be bad and still charge batt when driving??? Is it bad to disconnect the batt each time I turn off the vehicle, in case I can find the source over the weekend - Any help would be appreciated, can't afford to take it to a shop and I'd rather do it myself, if I can just go through the hassle of disconnecting the batt each time I shutdown w/o complications I'll do so till I can fix it - Inputs Plz Thanks, Tony
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes
You can do that... the only effect is that the ECM loses all it's learned about running the engine at its most efficient.

Have the alt tested... you dont say whether the car has a voltmeter on the dash, I thought they did. The drain problem MAY be somewhere else.
So maybe you should go to radio shack and buy a cheap vom while you're at it.
--
Yeh, I'm a Krusty old Geezer, staving off dementia here..DEAL with it!

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I will have access to a fluke multimeter over the weekend, hopefully I can find the problem. I'll get the alternator tested in the AM - So your saying it can drain my batt even if it seems to be working and charging the Batt??? - Hopefully it can be as simple as an alternator however I suspect something may be shorted in my trunk, since I was moving stuff and packing it, turn signals working intermittingly - I'll look there too
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

or like, a 'power inverter"?
--
Yeh, I'm a Krusty old Geezer, staving off dementia here..DEAL with it!

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes your alternator may charge the battery. Then when it sits overnight a bad diode in the alternator will allow the battery to discharge.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have the guy that owns the Fluke help you. :)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"kojmorbid" wrote

Might have dislodged the trunk light, so it's on all the time?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Well I will get back to you guys later on today and update you on what I've did,found,fixed etc - Then we can go from there - Thanks so far for the inputs -Tony
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ok guys this is where I am at and I am leading to bad alt - Thsi what I get from what I've read out
Engine Off- 11.97 Vdc Engine Idle - 12.03 Vdc Engine @ 2200 RPM - 12.37
Engine Idle w/ Lts On - 11.74 Vdc Engine @ 2200 RPM w/ Lts on - 11.88 Vdc
Neg Batt Term Wire - .1 Ohms Pos Batt Term Wile - .6 Ohms
Okay the Three wires going into the Alt on upper left side. Wires are old so I can confirm the wire color but here is the resistance of each Top Wire to Grd - 298 Ohms Mid Wire to Grd - .4 Ohms Bot Wire To Grd - .4 Ohms
Okay now who can help here, What I can see and please correct me if I am wrong is that my alernator is weak to charge - Isn't the Batt suppose to read around 13.5 to 14 Vdc while running esp. at 2200 RPM. I am guess since one of the phases into the alternator is High resistance it has lost a phase and isn't effectivly charging my Batt and maybe even draining my Batt because of it. Anyways does my troubleshooting sound correct, anyone know the resistance values of each phase in the alternator - Before I begin ripping out my alternator please give me your thoughts on it. Thanks for the help everyone, Tony
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
kojmorbid wrote:

It's most likely the alternator (diode). An alternator has three different windings, and it sounds as if you've lost one. A healthy alternator will output 13.5 to 15.0 volts (15V BRIEFLY), depending on RPM, temperature, and state of battery charge. A fully charged battery with no draw on it = 12.66 volts, and the charging device has to input at least 1/2 volt MORE than that to overcome internal resistances in wiring and the battery itself. In other words, 13.1 volts isn't charging the battery, but 13.3 volts is charging (VERY slowly).
)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Pulled Alt and sure enough it failed all test, Thanks for the advice - Installing new Alternator in the morning
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"kojmorbid" wrote

If the new alt comes with a new plug, use it. The nylon connector tends to get brittle with age, and can fall apart, creating a loose connection, or a possible short circuit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.