Interior wiring problem!

[taylorendicott]

Ok, I have an issue with my headlight, dash light, radio, and maybe even heater blower motor. I am going to attempt to describe to you the problem and symptoms to the best of my ability.

First off the problem: At night randomly when I'm driving my interior lights, headlights and radio will dim down to the point of almost being off and my radio will die; or everything is fine and I manually turn on my brights and whaaaam everything interior and exterior is dim.

During the dim:
My alternator light does not kick on.
The high beams imediatley go off.
The exterior lights dim.
The car drives fine idle, crusing, full throttle no problem.
The heater blower motor will slow down.
The radio will kick on and off like it is sucking to much juice (just a simple replacement stereo nothing fancy, it been in five years now).
If I turn the radio completely off and the heater off the lights wil brighten up alittle.
If I turn the car off they brighten back up.
If I Push the lock buttons twhen the car is shut off they lights dim even further.
That's all I can think of at the moment...

Things that might correlate with my problem:
Heater fan does not blow a hard as I think it should. ( the old and new blower motor work the same but don't blow as hard as i would like)
The auto dim for the head lights works randomly.

I'm sure it is just a ground problem but I need your input, wouldn't be a big deal but if something were to happen out on the road it's kinda hard to fix when it's 6degrees at night. It's supposed to be 1 degree at 6am. Thanks guys and if you have any questions about my description please ask.

[1990LTD]

a few questions that might help diagnose the problem:

What year is your car?

Does the alternator light come on when you turn your car on at first? It is supposed to. The light bulb in the dashboard completes your charge circuit and your alternator will not charge your battery without it.

Is it the stock alternator or have you upgraded to the 3G version? These cars came stock with 2G alternators that were not the best of designs and were quite weak in their output. Check for slack on the alternator belt....should be pretty taut.

In what condition is your battery? How old? You might be on to something suspecting a bad ground...you should have 3 ground cables coming off of your negative battery post, one grounds to the block, one grounds to the chassis, and the other one is a ground from the computer. It wouldn't hurt to clean up your ground points.

Do you own a multimeter?

It sounds like your alternator isn't charging the battery very well, or the battery is not holding a charge properly. That's just my .02

[86VickyLX]

a few questions that might help diagnose the problem:

What year is your car?

Does the alternator light come on when you turn your car on at first? It is supposed to. The light bulb in the dashboard completes your charge circuit and your alternator will not charge your battery without it.

Is it the stock alternator or have you upgraded to the 3G version? These cars came stock with 2G alternators that were not the best of designs and were quite weak in their output. Check for slack on the alternator belt....should be pretty taut.

In what condition is your battery? How old? You might be on to something suspecting a bad ground...you should have 3 ground cables coming off of your negative battery post, one grounds to the block, one grounds to the chassis, and the other one is a ground from the computer. It wouldn't hurt to clean up your ground points.

Do you own a multimeter?

It sounds like your alternator isn't charging the battery very well, or the battery is not holding a charge properly. That's just my .02

All good valid points, except for the bold, I don't believe the earlier panthers at least the '87 and down got the battery to rad support ground.
So just because you don't have it, doesn't mean you did.

[1990LTD]

All good valid points, except for the bold, I don't believe the earlier panthers at least the '87 and down got the battery to rad support ground.
So just because you don't have it, doesn't mean you did.

ahh okay, my bad.

[86VickyLX]

ahh okay, my bad.

It's all good.

[1990LTD]

oldest I've had so far is '88

[gadget73]

You definitely have ground problems. 87 may or may not have a battery to rad support strap, but it definitely has a battery to engine and an engine to body ground. The engine to body ground is attached to one of the bellhouse bolts and the other end is by the hinge on the passenger side. Pull and clean both ends of that cable, and pull and clean both ends of the battery to body cable. If either are in bad shape, broken, corroded, etc, replace them.

[taylorendicott]

It is a 1988 Lincoln Town Car
Yes the light does come on when I start the car, but goes off shortly after and does not come on when the problem happens
The car has been upgraded to a 3G, and the slack is taut.
The battery is a year old, top of the line AutoZone and the highest Cold Crank Amp they offered.
There are 3 grounds off the battery.
Yes I own a multimeter.
The cables are brand new, soldered and well lubricated with di electric grease.

NEW DISCOVERY!!!
The problem persisted even after shutting the car off and starting it back up to head home.
If I brake hard or take a hard right the heater motor speeds up and everything begins to work.

What needs to be checked with a multimeter.
Now a little of topic but on the boxes does the heater blow with far less velocity than when I A/C? Mine does.

[sly]

definitely check all ground cables to make sure the crimps are solid and bolted down.

also... you can check the issue of ground by holding a wrench from the - terminal on the battery to the upper tie bar (or use a fat wire and touch it to the - terminal and an unpainted bolt on the chassis somewhere). If stuff starts working, then the chassis ground is the issue. If that doesn't change anything... then it may be the voltage regulator.

[86VickyLX]

It is a 1988 Lincoln Town Car
Yes the light does come on when I start the car, but goes off shortly after and does not come on when the problem happens
The car has been upgraded to a 3G, and the slack is taut.
The battery is a year old, top of the line AutoZone and the highest Cold Crank Amp they offered.
There are 3 grounds off the battery.
Yes I own a multimeter.
The cables are brand new, soldered and well lubricated with di electric grease.

NEW DISCOVERY!!!
The problem persisted even after shutting the car off and starting it back up to head home.
If I brake hard or take a hard right the heater motor speeds up and everything begins to work.

What needs to be checked with a multimeter.
Now a little of topic but on the boxes does the heater blow with far less velocity than when I A/C? Mine does.

Yeah, it's blowing through the A/C evaporator and the heater core.
But not to such an extent that it's really gonna be noticed.

[gadget73]

If you have a bunch of leaves and junk in the evaporator or around the blower, it screws with the airflow. I've never been in a box that would part your hair though. They do have rather unimpressive HVAC airflow, but it seems to do the job.