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Posted by: biker bob Apr 6 2011, 02:47 PM

Started the car (72 2.0 L) this morning to go for gas. Alternator light stayed on for about 15 seconds after engine started then went out. Restarted the engine after getting gas and the light went out. Returned home no issues. Restarted engine after about 30 minutes. The alternator light came on and would not go out. Drove around the block and light remained on. Checked charging at battery NO charging.

2000 miles on new belt, new Bosche alternator,and new Bosche voltage regulator. Alternator wires properly plugged into the relay board. Belt properly adjusted. Transmission ground strap clean and tight. Help needed.

Posted by: McMark Apr 6 2011, 02:49 PM

Clean connection at the starter? Failed wiring harness?

Posted by: r_towle Apr 6 2011, 02:51 PM

give the voltage regulator a good solid tap tap tap and see if it charges.
Seriously.

Rich

Posted by: Jeffs9146 Apr 6 2011, 02:57 PM

If it still doesn't charge remove the voltage regulator and clean the contacts! Then if it still doesn't charge replace the voltage regulator!

Posted by: Drums66 Apr 6 2011, 02:58 PM

....after 2000mi alternator& or voltage reg....may be defective??
get system checked!

Posted by: biker bob Apr 6 2011, 03:14 PM

Clean tight conections at starter. Light still on.

Taping the voltage regulator did not make the light go out.

Posted by: r_towle Apr 6 2011, 03:20 PM

Sorry to say, pull the alternator and have it bench tested.
Its about a 30 minute job to pull it out the bottom.
It does come out.,..and its a PITA.

Some of the more recent "bosch" rebuilt starters and alernators are not super reliable.
I only bring mine to a local shop (thankfully they exist) that rebuilds them for me...

Rich

Posted by: biker bob Apr 7 2011, 05:23 AM

I have checked everything that has been suggested short of replacing the voltage reg and alternator. The one thing I have noticed is the alternator light is much brighter than normal. Could this be clue as to the problem?

Is there anyway to check the voltage reg other than replacing it?

Posted by: jt914-6 Apr 7 2011, 05:53 AM

Make sure you haven't kicked out a fuse getting in. Check all the fuses. Spin them in their holders. If the alt. light fuse is out/bad the light will stay on.....NAPA has a electronic version of the vr...Some Fords used the mechanical type vr''s too...

Posted by: Spoke Apr 7 2011, 06:32 AM

You can check the alternator in the car by disconnecting the VR and shorting the D+ and DF wires together from the alternator. This is equivalent to the VR asking the alternator to provide full charging. If the alternator is ok, you should see 16V or so on the battery.

BTW, the fuse you want to check is S9. S9 also powers the oil warning light so if that light is lit when you turn the key on, then S9 is ok.

Posted by: biker bob Apr 7 2011, 08:55 AM

One last thing to add. The brake warning light is blinking and will not stop after engine starts. It did stop blinking when the engine started before the alternator light started staying on. Thanks everyone for your suggestions and help.

Bob

Posted by: Spoke Apr 7 2011, 09:41 AM

About my little test, I should have added one more thing in this and it gets to a startup sequence with these alternators.

When you short D+ and DF together, this does tell the alternator to produce full charge. But you still need the alternator light connected to provide a bit of charge to "bootstrap" the voltage.

In other words, the light provides that little bit of electric current to start the alternator to produce voltage then D+ will power DF on its own and then you will be testing the alternator.

So, modified alternator test is this:

1) Remove VR.
2) Place a wire between D+ (spade towards front-right of car) and DF (spade towards front-left of car). This keeps the alternator light in the circuit for bootstrap purposes.
3) Start car, rev engine, measure battery voltage. Alternator light should go out too.

Posted by: 76-914 Jun 23 2011, 10:44 AM

Some great info here. Is there a way to bench test the alt at home? I tried several FLAPS a few years ago and none were able to bench check our externally regulated alt's.

Posted by: Dave_Darling Jun 23 2011, 04:36 PM

Brake light: Make sure the handbrake handle is down, pressing the button in the floor. Also try to reset the switch in the master cylinder; there should be a button covered by a rubber nipple. Press the button to reset the switch.

--DD