My Tractor Forum banner

1 - 20 of 34 Posts

·
Registered
Joined
·
1,247 Posts
Discussion Starter #1
I have a problem with my 1966 Impala. My courtesy lights won't shut off. So my battery discharges. Also the generator light stays on. I pulled my alternator yesterday took it in to get it tested and it was OK. I am not real familiar with trouble shooting wiring problems so any help will be much appreciated.

Thanks.
 

·
Super Moderator
Joined
·
31,892 Posts
Look at the door pin switch... They tend to rust up


as for the gen light..... been a LONG time sence I worked on a old GM so I would defer to someone else.... but check all wire connections!!!
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #3
All switches are brand new. Tonight I 'm going through to check wire connections and put some ground straps from the engine to the body and body to frame.

ALSO: It has a GEN light but it has a alternator and when I pull the battery cable off the car stops. The alternator has been tested as OK.

Thanks.
 

·
Super Moderator
Joined
·
31,892 Posts
Those door switches are grounding switches... trace the wires. One of them is probably worn through and grounding to the body.


As for the alt.... that should have a external reg in that year right??? That might be falty.
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #5
Is there a way to test the regulator? It was new last year. Is there anyway the horn relay would be the culprit? Here's the wire diagram.
 

Attachments

·
Registered
Joined
·
409 Posts
can't help ya with the wiring...but a 66' impala...nice car :thThumbsU
 

·
Super Moderator
Joined
·
31,892 Posts
OK... well just by looking at that dia.... I would look close at that splice where the power goes to the alt/reg/horn relay. May not be a bad idea to check those bulkhead connectors on a car that old also.
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #8
Agree . . . I just got the car back together last fall from a frame off. I have had this problem since I put it back together. I think I'll be paying close attention to clean the terminals and good grounds.:confused: This really has me scratching my head.
 

·
Registered
Joined
·
1,761 Posts
Your problem could be worse. I don't have my Impala anymore. Old Blue with 327 300 hp 4 spd. Hit in rear end and destroyed by a drunk.. Sounds lie these guys will get you fixed.
 

·
Super Moderator
Joined
·
31,892 Posts
Agree . . . I just got the car back together last fall from a frame off. I have had this problem since I put it back together. I think I'll be paying close attention to clean the terminals and good grounds.:confused: This really has me scratching my head.
In that case DEFENTLY check all grounds and those bulkhead connecters. I bet a bit of paint, or crud is the problem. Also are you sure you attached all ground cables?? A lot of the cars had a few small grounds from the body to the frame that tend to be forgotten about.
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #11
In that case DEFENTLY check all grounds and those bulkhead connecters. I bet a bit of paint, or crud is the problem. Also are you sure you attached all ground cables?? A lot of the cars had a few small grounds from the body to the frame that tend to be forgotten about.
I just bought new ground straps I'll be putting on the engine, body, frame, so that will be taken care of.:fing32: Then to sift through the other connections. I just got that wiring diagram off the web. I printed it at 20 x 24" so I can see it. At least now I know what's what.
 

·
Shop = My Therapy
Joined
·
3,157 Posts
I've wired a couple old cars. It sounds like a ground issue to me.
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #13
I guess I hope it is. . . Just need the basics working.
I want to do more on the wiring on it this winter. Plans include: Move battery to the trunk, install dual electric fans, finish installation of the Hot Rod air unit.
 

·
15,000 +posts!
Joined
·
20,538 Posts
If my brain recalls correctly,I think the #4 wire on the voltage regulator is the one that works the idiot light for "GEN"...if the pionts in the regulator dont close the light will stay on...sounds like its not charging though,if it stalls when you dissconnect the battery cable (a BAD way to test for altenator output,that can pop diodes,which will also make the "GEN" light stay on!)...

See if the two pronged plug on the altenator has 12V at both wires with the engine running..if only one does,then the field wont energize and it wont charge..the red wire on that plug stays hot all the time,the white or tan one next to it should only have current with the key "on" or the engine running...the large red wire on the stud in the rear of the altenator stays hot all the time too..sounds like the altenator isn't charging to me,and it can be "good" and not charge if the feild doesn't get energized..

I think the horn relay has a "junction" where two main red harness wires bolt together,but it doesn't carry any of the current for the charge system,the relay only operates the horn..as for the courtesy lights,I cant say much--maybe the contacts on the door switch or wires are touching ground inside the kick panel area ??..they work off a ground as far as I remember..
 

·
Registered
Joined
·
472 Posts
Definitely check the grounds. And the voltage regulator sounds suspect, even if new. And the horn relay can also be a problem. After doing the grounds, I would say the next step is the VR. Also, sounds like you have 2 separate problems, the charging system, and the lights...
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #17
UPDATE:
The GEN light is STILL on in my dash! I've replace, alternator, voltage regulator, and horn relay. I have 12.5 volts at the battery when the car is running. ***? . . . :banghead3
 

·
The voice of reason !
Joined
·
2,720 Posts
I've wired a couple old cars. It sounds like a ground issue to me.
:ditto:

I helped my brother with his restore and it had the same symptoms as yours.

It was a frame off so when he painted it all the ground points had beautiful pearl blue paint covering them and upon reassembly nothing worked right,until we went thru and removed paint around every ground strap on it (I think we did 7 total) and then all was good.

Good luck with the restore. Ron
 

·
Registered
Joined
·
1,247 Posts
Discussion Starter #19 (Edited)
I put new ground straps on it. One from the engine to the frame to the body. Cleaned them down to the bare metal. Every ground under the hood too. Guess i'll keep looking . . .:praying:

Is that Voltage regulator suppose to be grounded? It's mounted on rubber. If so, just off the frame of the VR?
:thanku:
 

·
Registered
Joined
·
48 Posts
If memory serves me right, some had a ground strap around the rubber grommet or a metal bushing inside it for grounding.Its a ways back to 66 .
 
1 - 20 of 34 Posts
Top