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Topic: Different charging issue and some other problems (Read 1815 times) previous topic - next topic

Different charging issue and some other problems

Hey all,

Bought an 87 TurboCoupe a few weeks back.  Car has a full load, including climate control and electronic ride control.  Really enjoy driving the little beast, however the previous owner was obviously a hack and I have some real wiring issues.  So I need to toss out a few questions:

1) Anyone know of a service manual online somewhere?  I saw the link to the EVTM and thank you very much. 

2) My most serious issue right now is a charging problem.  About 3 weeks ago, I noticed the battery discharging whenever the headlights were on.  Hooked up a voltmeter and got 13.3 volts with the car running and headlights off.  Turned on the headlights and the voltage dropped immediately to 12.1 volts and kept on dropping.  Revving to 3 grand brought voltage up to 12.5, but never above.  So I pulled the alternator and found it had been overheated at one point in time or another and was pretty much wore out in other areas.

So I replaced the alternator and found I had about 13.7 volts at idle and turning on the headlights resulted in the same voltage drop.  Revving the car brought it back to 13.7 this time though.  So I turned off the lights, allowed the battery to charge, then turned off the car.  I noticed the voltage kept dropping with the car off, until it dropped to around 8 volts or so, then held.  I grabbed a battery from my truck and tossed it in there.  Everything was fine after.  14.3 volts, headlights on resulted in slight voltage drop to 13.9, but slightly revving the engine brought everything back to 14.3.  Turning the car off resulted in a reading of 12.7 which held.

Thought I had everything figured out.

Now today, with the lights off, everything is working fine.  Alternators charging fine, cars starting fine.  As soon as the headlights are turned on, I'm seeing a voltage leak.  I haven't had a chance to pull the alternator and check to see if its burned out, but I doubt it.  I'm beginning to suspect a grounding issue with the headlight circuit.  Anyone have any other ideas?  And where do I find grounding points on this car?

Thanks in advance.  I have several other questions, but I'll save them until I have a chance to scour the forums and see if they've been answered elsewhere.

Rod

Different charging issue and some other problems

Reply #1
sounds a little crazy, but disconnect the headlight bulbs, then turn the lights on.... if it has a drop at all, it's the wiring....  i think that might work (unless it's a marker bulb wiring issue, but i'd hate for you to have to disconnect all those bulbs too).......  also turn the dimmer switch so the dash lights are in the off position.....  i've seen some headlight dimmer swithces go bad and do some funky things too :)


OOOH!!!  I'm a Eco Hypermiler :burnout: Not bad for 79mph on the interstate 2hours a day

Different charging issue and some other problems

Reply #2
Genereally the dimmer just burns out. Not always... I would look around and check if the voltage regulator is built into the alt or not. If it isn't, it can have a bad drain when the system is strained. I just had a problem with my alt, and it drained my battery when the car was running. It also drained it while the car was off. I swapped the alt and reg at the same time (there built in on the v-8's alts) and no more problems.
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

Different charging issue and some other problems

Reply #3
Quote from: mywifeskitty;245202
sounds a little crazy, but disconnect the headlight bulbs, then turn the lights on.... if it has a drop at all, it's the wiring....  i think that might work (unless it's a marker bulb wiring issue, but i'd hate for you to have to disconnect all those bulbs too).......  also turn the dimmer switch so the dash lights are in the off position.....  i've seen some headlight dimmer swithces go bad and do some funky things too :)


or just pull the fuse:D

good point though, circuit isolation is the best troubleshooting.

go to my diy link,, there is a link to a battery drain thread where I used a tiny ilttle bulb to isolate which circuit was causing the battery discharge.

Batteries and alternators should be replaced as a matched set.  in additon, imporper jump starts could have spiked the alt as well in addition to the fools who like to disconnect the battery when the car is running.

Different charging issue and some other problems

Reply #4
Quote from: jcassity;245224
go to my diy link,, there is a link to a battery drain thread where I used a tiny ilttle bulb to isolate which circuit was causing the battery discharge.


Yep, i saw that, thanks.  Unfortunately, I don't have a draw down (except the expected amount from radio memory) when the car is off and headlights off, only when its running with headlights on.  Otherwise, all is fine.  Which suggests I've found the problem circuit (headlights).  Now I've got to figure out what the problem is with that circuit.

I'm going to pull each bulb tomorrow and watch battery voltage.  Maybe I have a bad light socket.  Thanks for the info on the dimmer switch too.  I'll give that (and the fog lamp switch) a shot too.

I hate these doggoned wiring issues.  And this poor old girl has a few, including the previous owner bypassing the high/low pressure switch on the electric brake booster and installing a, yep, you guessed it, household light switch.

Do like this car though, when its not leaving me looking for a boost or a tow, lol.

Rod

Different charging issue and some other problems

Reply #5
Quote from: jcassity;245224
or just pull the fuse:D



yeah, that too... it would isolate it to the wiring if there is still a draw with no bulbs, but none if the fuse was pulled :)


OOOH!!!  I'm a Eco Hypermiler :burnout: Not bad for 79mph on the interstate 2hours a day

Different charging issue and some other problems

Reply #6
Speaking of fuses, anyone got a fuse box layout diagram?  Or is that in the EVTM?

Different charging issue and some other problems

Reply #7
I really need to open my eyes better.  Problem was a bad negative battery cable.  Off to town for some good solder ons and an eye exam...

We'll see if this doesn't get rid of some of my other gremlins, like the "headlights on, push power window down, radio goes off" issue.

Next on the hit list is the noisy fuel pump.  I see reference to a 255HP fuel pump.  I assume this is from a later model with more power like a SuperCoupe?  Will it work on my 87 Turbo?  Whats the part number?

Rod

Different charging issue and some other problems

Reply #8
your bosch pump is about 65Lph, the super charged 3.8 is 90Lph and offers a huge improvement over stock at a cost effective price.

The 255 is aftermarket.

 

Different charging issue and some other problems

Reply #9
Quote from: DiamondSCattleCo;245282


We'll see if this doesn't get rid of some of my other gremlins, like the "headlights on, push power window down, radio goes off" issue.



I seriously doubt it.  Sounds like someone found themselves a hot wire and used it.

Different charging issue and some other problems

Reply #10
Quote from: jcassity;245294
your bosch pump is about 65Lph, the super charged 3.8 is 90Lph and offers a huge improvement over stock at a cost effective price.


Direct bolt-in?  Do I need to change the whole assembly over, or just the pump?

Rod

Different charging issue and some other problems

Reply #11
no bolts:rollin:

the last SC 3.8 pump i bought came as a pump only with clamps, short 90deg hose, o-gring.

you resuse your housing, I would have metioned any complications on my other post, its a cut and dry install.

the sc pump three years ago was 45 dollars.

Different charging issue and some other problems

Reply #12
Quote from: DiamondSCattleCo;245282
We'll see if this doesn't get rid of some of my other gremlins, like the "headlights on, push power window down, radio goes off" issue.

Replace your ignition switch. If the connector is melted or burned, replace it too. It's a common problem with these cars.
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