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Topic: 87 Cougar Charging (Read 1120 times) previous topic - next topic

87 Cougar Charging

Finally got the car running and now there seams to be a no charge and slight drain.. battery new, alt new ... not sure about fuses from one point to another ..needing help (working in driveway and Canada is getting cold  haha)

87 cougar Ls
89 gt 5.0L H.O swap

-usually there is a battery light that comes on first in the dash before i crank but not anymore .

-battery holds charge in garage but not hooked up to car after a good nights sleep.

-at idle and higher rpm's battery sits at 11.31v

any troubleshooting tips/hints if you've been there anything really that will help or if im missing the the big picture and need to be pushed in the right direction .

im pretty sure there was alway a slight drain on the car since i got it even before the swap

Thanks!!

87 Cougar Charging

Reply #1 –
a bad diode will drain the battery and not let it charge while running. Take your alt to autozone and have it checked.

With my stock alt and heater headlights and anything else I could think of on, my car pulls 14.4 with the stock alt.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

87 Cougar Charging

Reply #2 –
I'd start by finding out why the charge light isn't functioning as it's grounded by the regulator in the alternator... Possibly the bulb has failed but I doubt it, should still charge even if it has... 

To check the bulb and it's associated wiring, ground the green with red stripe wire in the smaller plug on the alt... IF the bulb lights you have a alt problem, no if's,  and's or but's... If it doesn't light, you could have a wiring problem back to the bulb which could very possibly cause a no charge condition... There is a resistor across the bulb to excite the alt in event of bulb failure, so problem would have to to be between the plug and bulb... However none of these issues will cause a drain prob on the batt... Any chance the battery has been connected backwards and killed the new alt???

87 Cougar Charging

Reply #3 –
i had just grabbed a new alt today and it gave the same results as my old one, and i had just replaced the heater core so i did have the dash apart so ill take a look at the wiring tomorrow to see if anything was fubar'd when the gauges were removed.

TurboCoupe50 if the bulb is blown then the resistor would excite the alt and make you realize that the bulb is out by killing the recharge?

87 Cougar Charging

Reply #4 –
to check for drain.................
remove / borrow the tiny bulb mounted inside the headlamp switch (if it lights up still)

remove neg batt cable
remove all fuses(keep track fo who goes where)
gator clip / jumper wire one side of the bulb to the neg batt cable
gator clip/jumper the other side of the bulb to the batt - post.

does light come on?
if yes.....drain is contained within the engine bay fuse link circuits (ie-alt voltage reg) although you did say you put in a new alt.

if no
one at a time , install fuses until one fues makes the bulb come on.
ID the circuit by fuse panel markings and report back.

87 Cougar Charging

Reply #5 –
The resistor across the bulb only serves to excite the alt into charging in case the bulb is bad... As long as bulb is good, it serves no real purpose...

87 Cougar Charging

Reply #6 –
the bulb was unpluged, hooked it up and i have 14.38v all the time! ford is such a funny thing sometimes

thank you all

87 Cougar Charging

Reply #7 –
then the parallel resistor is open.