Daily Driver Glitch..

[Arnold]

01 Focus Wagon. Close to new condition. Meticulously maintained. Not by me lol. Loaded. The ONLY problem this car has ever had was F. whl. bearings!.
  The battery..a very good one! is not even a year old. And was recently tested..as was the alternator/charging system.
 
  A few weeks ago the batt. light ( alternator charging light I assume?) came on while driving. Then went off a minute or so later.
  Now..it comes on every time..after it has been driven for about 5-10 minutes..(only from a cold start overnight)..and stays on only for a minute or so then  goes off.
 Everything else is normal. Turn the key on. Light comes on as it should. The engine starts it goes off as it should. Comes back on for a minute after 5-10 minutes of driving then goes off again lol. Just to annoy me haha.

  Any help,ideas would of course be welcome!

   Thanks..Arnold..

[wayne petty]

lets start with a voltage drop test...


Voltage Drop Testing

Set digital volt meter to 20 volt DC scale.

Start engine, turn on the headlights.

1.  Measure from the positive battery post to the negative battery post.    14.1 to 14.7 volts DC

    You might need to turn volt meter setting to 2 volts DC for tests 2, 3, 4.

2.  Measure from the negative battery post to the Engine block.                0.04 volts is expected.

3.  Measure from the negative battery post to the body.                             0.02 volts is expected.

4. Measure from the Engine to the firewall.                                                0.02 volts is expected.

This test takes less than 3 minutes to do and is the start of any diagnosis

Reason behind these tests.   Electrons flow from negative to positive if you don't have a proper ground between all the parts, when electrical loads are turned on. There may not be enough connection to properly power the device.  

Test 1. Shows that the charging system is working properly.  If you don't have above 14.1 volts. There is a problem.  Continue the tests.

Test 2. Shows that the connection between the engine block and the battery negative post is working properly. There is another test done while cranking or attempting to crank the engine with the same test locations. While cranking.. the volt meter should show less than 1.0 volt. I like to see less than 0.5 volts but this depends on the thickness of the battery cables.

Test 3. Shows the connection from the negative battery to the body. Why is this important. Almost everything in the car is grounded to the body of the car. Without this ground there will not be enough electrons to power your devices.

Test 4.  Shows the connection needed between the engine and the firewall.  Why. The alternator put out electrons from the negative side.



on fords.. there are various ground connections scattered around the engine bay..  usually up on the core support.. i have not been under the hood of these lately.. so i don't know where all the ground connections are.. i can find out if you need..


if you could also post if its a single over head cam or a dual over head cam motor..

the voltage drop test above is the first step. in diagnosing this..

with your volt meter.. can you monitor the charging system voltage next..

it should be 14.1 to 14.8 volts with the engine running..

could the belt be slipping.. the tensioner not holding the belt tight..

is the belt warn so the grooves are not setting in the grooves but running in the bottom where there won't be enough friction to turn the alternator at the proper speed..

you might also want to match mark the crank damper pulley.. inside and outside.. as there have been too many problems with other ones right now..

with the belt off.. do the other pulleys turn easily???

it still could be an electrical problem...

post results..

[wvcab]

check the back of the altenator.... i believe there is a single wire on a slip on type connector, this goes to the "battery lite". they do get corroded and will cause intermittent lite problems.

[butch27]

Wayne: Thanks for the instructions. I never did learn to use one of those things correctly.

[Arnold]

Thanks very much for the help,replies!/I appreciate them!

  To be honest I have not even looked at this myself.

  The shop that services(d) my cars for the last few years..and the guys that work there are seriously top notch! I have nothing but the utmost respect for them. I had done ALL my own work..and others..for..ever. Until I moved..and things were in a state of chaos.. so I lucked onto a great shop! lol..now I am back living in the middle of nowhere(where I belong). SOOo..I will pretty much have to go back to taking care of my own stuff!

 I cannot imagine that those guys missed anything! Never know. Everything tests out fine when cold..and hot. It is just that brief period for a minute in between. lol.of course when the light came on..it did not stay on for long enough to catch anything wrong.

 GRRRR..yesterday and today..it almost seems as if this thing is on a timer haha. Just to annoy me. If I start the car and shut it off before it gets to set the light on.lol..it just seems to wait until it has run for long enough in total to do it haha. I drove it a very short distance this morning..not enough to set the light on..but I know that when I drive it again in a few minutes it will do it again for a minute haha once I have driven it the required distance. Then it will go off..and stay off  for the rest of the day..until tomorrow haha.

  Wayne..thanks again..I will do those tests in the next week or so. This is the sohc motor.

  Thanks again..Arnold..