Re: [Chevelle-list] wiring question

[Leo John Costigan]

What you need to do now is with ign in run, go to the senders unplug them and 
check for voltage at the plug. Either with a voltmeter or test light. This is 
checking continuity from the gauges to the sender’s plugs.  If you have 
continuity then there is a grounding issue.

If you have no voltage at the unplugged sender plugs then there is open wire to 
the gauges.

 

Leo

Re: [Chevelle-list] wiring question

[Jim Thompson]

Just a few questions. Can you start the engine? Are you sure the gauges are 
wired correctly? 

 

I understand your confusion, just went through this myself. 

 

I will start with the temp gauge. The sender is screwed into your block, head 
or manifold. This contact grounds the sending unit. The ground is not complete 
until it gets hot when a bimetal contact expands inside the sender. The wire to 
the sender goes to the back of the gauge. The other wire on the gauge goes to 
the fuse block and is hot in the “on” mode. In a stock GM harness several hot 
leads come together and are simply twisted and soldiered in a bunch with tape 
wrapped around it. If you have a test light check both sides of the fuse with 
the key on and off. If the light goes on and off at the fuse box using the key 
repeat the test at the back of the gauge. If the light fails at the back of the 
gauge try using a jumper wire straight from the fuse box. If this fails run a 
wire to the sending unit. If this fails replace sending unit.

 

The secret is start where you know you have power test each link until you lose 
the power then back track.

 

The sender has a float like the one in your toilet. As it goes up and down the 
resistance changes. Under the carpet is a flat harness that has a connector 
under the dash and under the back seat. The tan wire can be tested at both 
locations, these do not usually fail. So if you have power at the gas tank 
sending unit skip, testing those connections.  

 

The fuel gauge sender has one tan wire (hot) and one black ground. Check the 
tan wire with the test light. Turn the key to “on’ before you get under the 
car. If it is hot at the sender I would make sure the ground wire is good. The 
test light ground wire should be clipped on the sender where the normal ground 
wire is attached and the probe inserted into the connector on the tan wire this 
way you test your ground. If it fails move the ground of the test light to some 
part of the body. If it works then I would replace the end of the ground wire 
and clean all the rust around the screw hole in the body. One trip under the 
car is enough. 

 

If all this does not help I would suspect that you have wired the gauges 
incorrectly.

 

From: chevelle-list-boun...@chevelles.net 
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.net
Sent: Tuesday, February 02, 2010 7:54 PM
To: The Chevelle Mailing List
Subject: Re: [Chevelle-list] wiring question

 

Jim I appriciate your help. It seems to me Iam being told 2 different things 
here. Leo say's there should be no power at pins 10 and 11 and it sounds to me 
like your telling me there should be power at those pins. I dont understand the 
principles of operation here. I dont understand how they work.I hope someone 
here can explain to me exactly how it works. Does 12 volts go through the guage 
and the sending units add resistance to ground. Thanks every body for your help 
here. I just wanna get my guages working.
- Original Message -
From: "Jim Thompson" jimthompso...@gmail.com 
To: "The Chevelle Mailing List" 
Sent: Tuesday, February 2, 2010 7:10:29 PM GMT -05:00 US/Canada Eastern
Subject: Re: [Chevelle-list] wiring question

I will suggest again that ground is critical. Your fuel sending unit should 
have its own ground wire. The temp sending unit is hot, internally the switch 
closes to ground. With the key to “on” both should be hot. Your fuse box should 
have one fuse marked “gauges” if it is hot on both sides. Then it is a ground 
issue or short in the gauge harness.

 

From: chevelle-list-boun...@chevelles.net 
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.net
Sent: Tuesday, February 02, 2010 4:25 PM
To: The Chevelle Mailing List
Subject: Re: [Chevelle-list] wiring question

 

Does anyone know where the voltage for the fuel and temp. guages is fed from. I 
have voltage to everything except these two guages. I unplugged the 12 pin 
connector that plugs into the pcb and checked  for voltage there. everything is 
hot with the exception of temp and fuel. all my fuses are good. Any 
ideas.Thanks, Bob
- Original Message -
From: dhoesc...@granitecityperformance.com
To: "The Chevelle Mailing List" 
Sent: Monday, February 1, 2010 10:03:58 PM GMT -05:00 US/Canada Eastern
Subject: Re: [Chevelle-list] wiring question

I would suggest disconnecting the tan fuel sender feed wire at the fuel tank. 
Turn the key to RUN position and wait a few moments (some gauges are slow) with 
the tan wire disconnected the fuel gauge should read past full. Then ground the 
tan wire anywhere to the body and the gauge should read empty. If you get no 
response then you have a bad gauge or a wiring problem.

-Original Message-
From: "Tom Rightler" 
Sent: Monday, February 1, 2010 20:47
To: "'The Chevelle Mailing List'" 
Subject: Re: [Chevelle-list] wiring question

If you want to check the gauges, send 12 volts directly to them and see if the 

Re: [Chevelle-list] wiring question

[rml438]

Leo, Thanks for all your help. I just checked for voltage at the back of the 
guages, with everything plugged in, and the key in the run position . I have 
voltage on both the temp and fuel guage. So knowing there is power to the 
guages, does this narrow my search down to a ground..- Original Message 
- 
From: "Leo John Costigan"  
To: "The Chevelle Mailing List"  
Sent: Tuesday, February 2, 2010 9:51:22 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [Chevelle-list] wiring question 

 


Bob, Jim is right. With the cluster plug connected to the cluster and Ign 
switch in run, you should have 12v when you disconnect the plug at either the 
temp sender or fuel sender. If you don’t, then there is an open somewhere 
between the gauge fuse and the sender plugs. 

You can use a test light and disconnect the sender plugs and connect the test 
light to these connectors. The light should light but it will be dim. 



As for grounding; 

You should ground the engine to the frame and to the body. 

You should ground the body to the frame. 

The cluster should be grounded to the dash frame. 

The headlight should be grounded to the cluster by a shorting strap. 

The fuel tank should be grounded to the frame. 



All of these grounds need to be in place to eliminate any grounding loops. Bad 
grounds will give bad readings and can cause you to go around in circles. 



You did indicate that your gauges never did work. My 70 El Camino had a problem 
that was caused by the amp meter wires had melted in the dash harness.   There 
was no indication of a problem except that the amp didn’t move. The outside of 
the harness looked good.   I found the problem when install a TPI engine and 
rewired the harness for the computer and upgrade for glass fuse to ATO. Several 
of the wires were melted together.   These old original harness are in bad 
shape. 



Do check the grounds. 



Leo 


- Original Message - 
From: rml...@comcast.net 
To: The Chevelle Mailing List 
Sent: Tuesday, February 02, 2010 4:53 PM 
Subject: Re: [Chevelle-list] wiring question 


Jim I appriciate your help. It seems to me Iam being told 2 different things 
here. Leo say's there should be no power at pins 10 and 11 and it sounds to me 
like your telling me there should be power at those pins. I dont understand the 
principles of operation here. I dont understand how they work.I hope someone 
here can explain to me exactly how it works. Does 12 volts go through the guage 
and the sending units add resistance to ground. Thanks every body for your help 
here. I just wanna get my guages working. 
- Original Message - 
From: "Jim Thompson" jimthompso...@gmail.com   
To: "The Chevelle Mailing List"  
Sent: Tuesday, February 2, 2010 7:10:29 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [Chevelle-list] wiring question 




I will suggest again that ground is critical. Your fuel sending unit should 
have its own ground wire. The temp sending unit is hot, internally the switch 
closes to ground. With the key to “on” both should be hot. Your fuse box should 
have one fuse marked “gauges” if it is hot on both sides. Then it is a ground 
issue or short in the gauge harness. 





From: chevelle-list-boun...@chevelles.net 
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.net 
Sent: Tuesday, February 02, 2010 4:25 PM 
To: The Chevelle Mailing List 
Subject: Re: [Chevelle-list] wiring question 




Does anyone know where the voltage for the fuel and temp. guages is fed from. I 
have voltage to everything except these two guages. I unplugged the 12 pin 
connector that plugs into the pcb and checked  for voltage there. everything is 
hot with the exception of temp and fuel. all my fuses are good. Any 
ideas.Thanks, Bob 
- Original Message - 
From: dhoesc...@granitecityperformance.com 
To: "The Chevelle Mailing List"  
Sent: Monday, February 1, 2010 10:03:58 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [Chevelle-list] wiring question 

I would suggest disconnecting the tan fuel sender feed wire at the fuel tank. 
Turn the key to RUN position and wait a few moments (some gauges are slow) with 
the tan wire disconnected the fuel gauge should read past full. Then ground the 
tan wire anywhere to the body and the gauge should read empty. If you get no 
response then you have a bad gauge or a wiring problem. 

-Original Message- 
From: "Tom Rightler"  
Sent: Monday, February 1, 2010 20:47 
To: "'The Chevelle Mailing List'"  
Subject: Re: [Chevelle-list] wiring question 

If you want to check the gauges, send 12 volts directly to them and see if the 
needle moves.  If the needle moves, the gauges is good and there are wiring 
issues elsewhere.  I’ve seen brand new sending units fail.  There should be 12 
volts at the bulkhead connector with the key in the run position for all wiring 
to the gauges. 



Tom 



-Original Message- 
From: chevelle-list-boun...@chevelles.net 
[mailto:chevelle-list-boun...@chevel

Re: [Chevelle-list] Looking for Alex LaRue

[Barnes, Alex]

Donnie, differant Alex here.



From: chevelle-list-boun...@chevelles.net
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of
donnie...@aol.com
Sent: Tuesday, February 02, 2010 8:22 PM
To: chevelle-list@chevelles.net
Subject: [Chevelle-list] Looking for Alex LaRue


Alex,
 
Please let me know how to contact you.
 
Thanks
 
Donnie Gates
Maryland Chevelle Club

Re: [Chevelle-list] Looking for Alex LaRue

[Alex LaRue]

Thanks Larry.

-Original Message-
From: chevelle-list-boun...@chevelles.net
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of Larry Williams
Sent: Tuesday, February 02, 2010 10:05 PM
To: The Chevelle Mailing List
Subject: Re: [Chevelle-list] Looking for Alex LaRue

http://www.larueinsurance.net/larueins.html

Larry

Re: [Chevelle-list] Looking for Alex LaRue

[Alex LaRue]

My contact info.  Thanks.

 

Alex LaRue
LaRue Insurance, Inc. (800)303-3518   
P O Box 119   Fax (270)358-8978
54 Lincoln Square
Hodgenville, KY  42748ACES  4711 

 

 

 

From: chevelle-list-boun...@chevelles.net
[mailto:chevelle-list-boun...@chevelles.net] On Behalf Of donnie...@aol.com
Sent: Tuesday, February 02, 2010 8:22 PM
To: chevelle-list@chevelles.net
Subject: [Chevelle-list] Looking for Alex LaRue

 

Alex,

 

Please let me know how to contact you.

 

Thanks

 

Donnie Gates

Maryland Chevelle Club

<><>

Re: [Chevelle-list] Chevelle-list Digest, Vol 79, Issue 8

[Chris Lord]

I have 67-72 chevelle wiring diagrams if that would help you, or anyone else for that matter. just give me an email to send it to
Ben
b...@gwi.net

On Feb 2, 2010, chevelle-list-requ...@chevelles.net wrote:

Send Chevelle-list mailing list submissions to chevelle-list@chevelles.netTo subscribe or unsubscribe via the World Wide Web, visit http://chevelles.net/mailman/listinfo/chevelle-listor, via email, send a message with subject or body 'help' to chevelle-list-requ...@chevelles.netYou can reach the person managing the list at chevelle-list-ow...@chevelles.netWhen replying, please edit your Subject line so it is more specificthan "Re: Contents of Chevelle-list digest..."

Today's Topics: 1. Re: wiring question (rml...@comcast.net) 2. Looking for Alex LaRue (donnie...@aol.com) 3. Re: wiring question (Leo John Costigan)


Jim I appriciate your help. It seems to me Iam being told 2 different things here. Leo say's there should be no power at pins 10 and 11 and it sounds to me like your telling me there should be power at those pins. I dont understand the principles of operation here. I dont understand how they work.I hope someone here can explain to me exactly how it works. Does 12 volts go through the guage and the sending units add resistance to ground. Thanks every body for your help here. I just wanna get my guages working.- Original Message -From: "Jim Thompson" jimthompso...@gmail.com To: "The Chevelle Mailing List" Sent: Tuesday, February 2, 2010 7:10:29 PM GMT -05:00 US/Canada EasternSubject: Re: [Chevelle-list] wiring question

I will suggest again that ground is critical. Your fuel sending unit should have its own ground wire. The temp sending unit is hot, internally the switch closes to ground. With the key to “on” both should be hot. Your fuse box should have one fuse marked “gauges” if it is hot on both sides. Then it is a ground issue or short in the gauge harness.
 


From: chevelle-list-boun...@chevelles.net [mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.netSent: Tuesday, February 02, 2010 4:25 PMTo: The Chevelle Mailing ListSubject: Re: [Chevelle-list] wiring question


 

Does anyone know where the voltage for the fuel and temp. guages is fed from. I have voltage to everything except these two guages. I unplugged the 12 pin connector that plugs into the pcb and checked  for voltage there. everything is hot with the exception of temp and fuel. all my fuses are good. Any ideas.Thanks, Bob- Original Message -From: dhoesc...@granitecityperformance.comTo: "The Chevelle Mailing List" Sent: Monday, February 1, 2010 10:03:58 PM GMT -05:00 US/Canada EasternSubject: Re: [Chevelle-list] wiring questionI would suggest disconnecting the tan fuel sender feed wire at the fuel tank. Turn the key to RUN position and wait a few moments (some gauges are slow) with the tan wire disconnected the fuel gauge should read past full. Then ground the tan wire anywhere to the body and the gauge should read empty. If you get no response then you have a bad gauge or a wiring problem.-Original Message-From: "Tom Rightler" Sent: Monday, February 1, 2010 20:47To: "'The Chevelle Mailing List'" Subject: Re: [Chevelle-list] wiring question
If you want to check the gauges, send 12 volts directly to them and see if the needle moves.  If the needle moves, the gauges is good and there are wiring issues elsewhere.  I’ve seen brand new sending units fail.  There should be 12 volts at the bulkhead connector with the key in the run position for all wiring to the gauges.
 
Tom
 
-Original Message-From: chevelle-list-boun...@chevelles.net [mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.netSent: Monday, February 01, 2010 9:01 PMTo: The Chevelle Mailing ListSubject: Re: [Chevelle-list] wiring question
 

The sending. unit is grounded to the body, and the temp sending unit is new. Tom,do you know if there would or should be voltage at the 12 point  connection into the pcb. for the temp and fuel guages- Original Message -From: "Tom Rightler" To: "The Chevelle Mailing List" Sent: Monday, February 1, 2010 8:53:30 PM GMT -05:00 US/Canada EasternSubject: Re: [Chevelle-list] wiring question
Is the fuel sending unit grounded to the body?  If the temp gauge isn’t working, it’s usually a problem with the sending unit screwed into the head.
 

Tom Rightler
MCC Newsletter Editor
http://www.chevelles.net/mcc

 
-Original Message-From: chevelle-list-boun...@chevelles.net [mailto:chevelle-list-boun...@chevelles.net] On Behalf Of rml...@comcast.netSent: Monday, February 01, 2010 8:32 PMTo: The Chevelle Mailing ListSubject: Re: [Chevelle-list] wiring question
 

I'am a firm beliver that there is no such thing as a dumb question. My dash lights are working fine. the dimmer switch is working I just do