Chevelles.com banner

1 - 20 of 30 Posts

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #1
I am having an electrical problem with my 67 Elky. Alternator light stays on as long as key is on. Voltmeter reads about 12 1/2V @ idle, increases with engine RPM until the gauge is pegged, then drops again at idle. With headlights on, v/meter reads 12 - 13V regardless of RPM. My best guess is the regulator. Should the case be grounded? When I test it, the mounting screw are grounded but not the case. I just hate to start replacing parts without being pretty sure.
John

------------------
TC# 958
'67 Elky 396/325 TH400
----------------------------
"Speed Costs Money -
How Fast Ya Wanna Go?"
 

·
Registered
Joined
·
7,762 Posts
Troubleshooting a GEN light problem.
1, Remove the plug from the regulator.
2, Turn the ignition key to the ON position.
3, Measure the regulator connector brown wire to a good ground.
You should have around 12 volts.
4, If (3) is around 12 volts, switch the key to OFF.
5, Install the regulator connector.
6, Remove the plug from the alternator.
7, Turn the ignition key to the ON position.
8, Measure the alternator connector blue wire to a good ground.
You should have around 12 volts.
9, If (8) is around 12 volts, switch the key to OFF.
10, Install the alternator connector and start the engine.
11, Again measure the alternator connector blue wire to a good ground. You should have around 12+ volts.
Post back the results.
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #3
John,
#3 = 12V

#8 = 12V

#11 = 1.8V (this is with the blue wire plugged into the alt, and voltmeter from blue connector to ground)
John
 

·
Registered
Joined
·
7,762 Posts
Unless this is a brand new alternator, problem is with the field output from the alternator. Suggest getting that checked.
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #5
This is an old alternator, was on the car when I bought it 2 years ago. Maybe this would be a good time to convert to an internal regulator type, if I need to replace it.
John
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #6
John
I decided to replace the alternator with a stock replacement. Same deal, only now I have about 2.8 - 3V on the blue wire, connected to the alternator and engine idling.
John
 

·
Registered
Joined
·
7,762 Posts
Try flashing the new alternator. Touch a piece of wire from blue to the large red output wire. Do this for a couple of seconds. See if that starts the alternator.
*Edit*
Car running when doing this.

[This message has been edited by John_Muha (edited 08-07-2002).]
 

·
Registered
Joined
·
7,762 Posts
Still sounds like alternator. I mess up more times that not, but the field voltage is not coming up. I know it's a pain but have them check the alternator.
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #10
Will do. I will take it back to Auto Zone, tomorrow after work. Will post back Friday night. Thanks Hohn, appreciate the help.
John
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #11
John,
I took the alt. back to Advance (not AZ). They will replace it. I asked them to test it , and the guy said it was defective, 'only putting out 10V. I asked about the field output and he said he was "testing it all"! OK. I'll have the new one in the morning. Ill let you know.
Back to the problem at hand. I dont (obviously) understand a lot about the charging system. How can my voltmeter in the car be reading 12, 14, 16 volts if the alternator isnt 'turned on'? I have to keep the lights and fan on to keep the v in the 12 -13 range above an idle.
John
 

·
Registered
Joined
·
7,762 Posts
Yes it's possible for the red output lead to make everything look ok. However, there could still be a problem out the blue field wire. Guys like Peter F. can explain it better than I. His background is power generation, while I took a different route many years ago.
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #13
OK, Heres the latest. Put on the new alt, and decided to go the $12 for a new regulator too. Now the idiot light is on at idle, with Vmeter in car at 11.5 V, Engine speed up to 1500, light out and meter at 12. Never goes over 12, and light come back on at idle. Bring RPM up to about 1500, idiot light out, Vmeter at 12, turn on headlights and meter drops to 11.5, regardless of engine speed. Seems closer but not quite right yet.
John
 

·
Registered
Joined
·
7,762 Posts
Shoot, dang thing is just not going. Regulator have a ground strap to the core support? Did you try flashing the new alternator? You are disconnecting the battery when you install these items?
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #15
John,
Battery disconnected - ground reconnected last. I left out one of the rubber mounts to the radiator support (for the reg) so that the reg is grounded. Tried flashing the alt and got BIG spark but nothing changed. Read voltage at blue connection (F) with car idling, 11.8V. Battery is 12.3 with key off. New cables etc. already installed prior to beginning of all this.
 

·
Registered
Joined
·
7,762 Posts
Borrowed some of Peter's past stuff. Maybe that might lead to an answer.

Peter F.
Tech Team
From: Harriston, Ontario, Canada
Registered: Dec 99
posted 05-21-2002 10:46 PM
---------------------------------------------
If the alternator tests OK then look at the regulator.
First off. When you put the regulator down in front of you with the terminals facing you the numbering should go F, 2, 3, 4 from left to right.

The wire going to the #2 terminal at the regulator should go up to a few volts once the car is started. This wire turns on the regulator and the regulator requires 1.5 to 3.2 volts to energize it. If the voltage is higher than that, it should be working.

When the regulator engages, the wire on terminal 4 should go to full or battery voltage. That's the wire the light goes to.

The wire on terminal 3 should have battery voltage on it at all times.

When off and the wires connected, check for continuity between regulator terminals F and 4. Should be a short.

When running, jumper the F terminal and the big power lug together on the alternator. This should easily produce voltages of 16 or 17 volts at idle or with a slight rev of the engine. Make sure anything electronic is off when doing this, such as stereo equipment. I can't remeber the wire colours, so just follow the F terminal from the regulator.

When you disconnect the regulator, the light should go out.

If you pull the regulator cover, you should see 2 coil and contact assemblies. 1 will have a single contact. This is the energize coil. It should be closed whenever the car is running. The other coil/contact assembly will have 2 contacts with the middle being double sided. This is the regulating coil. It should bounce between the contact sets while the car is running.

That's all I have. Let us know what you find.

Peter
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #17
Ok, here goes:
reg case is grounded

Wire to #2 - 4.5V running

terminal #4 - 6V running

Terminal 3 - 12+V

NO continuity between terminals 3&4

Jump from terminal F(1 or Blue) to alt = 11.5 on car voltmeter - no change with rpm.

This reading is constant as long as engine is running,even when driving around the block. may go slightly higer (12) at 200 rpm.

Disconnect regulator harness = idiot light out.

Cover is riveted - can't remove. Dont know if the new regulators have these same innards or not.

John

[This message has been edited by phocksphyre (edited 08-11-2002).]
 

·
Premium Member
Joined
·
4,131 Posts
John remove the plug from the regulator and jumper the plug from F to 3( not the regulator...the plug.) Start the car and measure voltage across the battery at around 2000RPM. What you have done at this point is to give the alternator full field current. If the alternator does not give you maximum output then it is bad. If it does work properly then your regulator is bad or you have some other wiring problem.

This test is solely intended to prove the alternator is working properly. Post the results please and we will go from there.
 

·
Registered
Joined
·
7,762 Posts
The field voltage is still low. Yeah, try Bill's idea. $12.00 and rivots in the regulator cover? Guessing you bought a Wells VR715 solid state regulator. If you did there are no internal adjustments. They are plug and play.

Since you changed the regulator, might want to recheck the alternator field wire. Unplug the alternator connector, measure the blue field wire to a good ground again with the key on, car not running. Should again get the battery 12 volts.

Car off, unplg both the alternator and regulator connectors. measure to see if the #2 relay wire is not open between the regulator connector and the alternator connector. Doesn't sound like it is but running out of ideas.

If all that checks out (again) and Bill's idea still doesn't start the alternator, I still think it's the alternator. Been wrong before, but I sure can't see what I am missing.
 

·
Premium Member
Joined
·
1,261 Posts
Discussion Starter #20
OK.
Jumped plug from F to #3 -12.2V @2000 RPM at battery terminals.

New wells vr715 regulator.

#2 relay wire continuos circuit from plug to plug

Alt field (blue) wire is 11.5V - key on, not running.
I appreciate the effort you guys are expending.

John

[This message has been edited by phocksphyre (edited 08-11-2002).]
 
1 - 20 of 30 Posts
Top