Testing Gages - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old May 21st, 06, 07:04 PM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Testing Gages

My saga continues.....temp and fuel gages on my 68 console will not work. On the fuel gage, I tested the sending unit when I changed the tank with an ohm meter and it worked great. I have 12v on the pink feeding the one side of the console gage and about 3.5 volts if I measure accross the gage, if I disconnect the sending unit the voltage jumps to about 6.5 volts. I triple checked the ground and it is good...any hints on what to look for next or is the gage screwed?

On the temp gage I bought a new sensor for the block and I do not know what to look for next.

The gages are original so I am leaning towards the fact that they are both screwed.

Any hints would be appreciated!

Thanks

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old May 21st, 06, 07:51 PM
Senior Tech
 
Join Date: Jul 2001
Location: Pontiac IL
Posts: 453
Send a message via AIM to undee72Z
Re: Testing Gages

Both gauges have 3 electrical connections, power, ground, and sending. First be sure both have power and are grounded. I am not familer how they are grounded (whether by a wire or the gauge itself, some else may chime in on this) after having proper power and ground, you can test the gauges with the sending wire. With the sending wire not connected to anything fuel should be pegged to "F" and temp to "C". With the sending wires grounded fuel should be pegged to "E" and temp to "H". If this happens, gauges are working correctly.

Greg U

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
undee72Z is offline  
post #3 of 14 (permalink) Old May 22nd, 06, 06:57 AM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

The gages appear to be fine then as they test out as you described above.

I guess I will have to concentrate on the sending units then. I may have damaged the tank unit installing it and who know if the temp sending unit was defective from the start.

Thanks

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
 
post #4 of 14 (permalink) Old May 22nd, 06, 12:32 PM
Senior Tech
 
Join Date: Jul 2001
Location: Pontiac IL
Posts: 453
Send a message via AIM to undee72Z
Re: Testing Gages

The temp sending unit must be for gauges. With a idiot light sending unit, the gauge would never move till the car overheated since it is basicly a on/off type for the light. To test temp sending units for gauges see here
http://www.madelectrical.com/worksho...mp-gauge.shtml
You also post on the Chevelle board too?

Greg U

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
undee72Z is offline  
post #5 of 14 (permalink) Old May 22nd, 06, 04:06 PM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

I am getting more and more confused trying to solve this problem. I took the temp sending unit, which I had bought brand new, and heated the element to see if I would get a change in resistance across the sensor which I did. I had another used one around and it was almost identical in the changing resistance with the addition of heat.

I would be curious to know what the voltage should be after the gage and at the plug in the trunk that connects to the sending unit, also what it should be at the temp sending unit on the motor.

If anyone could post the above info I would appreciate it.

Thanks

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
post #6 of 14 (permalink) Old May 24th, 06, 08:13 AM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

I have troubleshoot this to death and I think that the fuel gage is toast. It will cycle as undee72z suggested but when I dug a little deeper and read what Jim had cut and pasted in from the Chevelle site in the electrical troubleshooting and followed that process through it will not register any level. I checked the resistance at the connection in the trunk and got 52 ohm's about 1/2 tank. Disconnected at the gage and measured it and got almost the same 51.8 ohm's, when I connect it back up to the gage it drops to 15 ohm's. And like I posted earlier the voltage drops significantly when it flows through the gage.

I will change the gage and see what happens.

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
post #7 of 14 (permalink) Old May 24th, 06, 10:03 AM
Gold Lifetime Member
Jim
 
Join Date: Dec 1999
Location: Yorkville, Illinois USA
Posts: 22,121
Re: Testing Gages

give it a try if you have one handy, but...

making a resistance measurement with the circuit connected to the guage is putting the internal resistance of the guage into a parallel circuit with the internal resistance of the sender. That's what is changing the reading, tho I do not know what that correct reading would be.





To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
New website for my vert is coming together. Do ya like the slide show on the home page?
JimM is offline  
post #8 of 14 (permalink) Old May 25th, 06, 04:17 AM
Senior Tech
 
Join Date: Jul 2001
Location: Pontiac IL
Posts: 453
Send a message via AIM to undee72Z
Re: Testing Gages

Maybe you have a power or ground problem. Check the voltage, at the power wire at the gauge with everything hooked up. Voltage should be close to battery voltage. If its a lot lower, you have a power problem.

Greg U

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
undee72Z is offline  
post #9 of 14 (permalink) Old May 25th, 06, 06:55 AM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

The temp and fuel gages are fed from the same pink wire and prior and that voltage reads the same as the battery when disconnected from the gage. When I plug in the gage and read the voltage it drops to about 6.5V with the sending unit disconnected and when I reconnect the sending unit it drops again to around 3v. This is why I am leaning towards a gage issue.

By the by I have checked the grounds and even ran an express line back to the battery to make sure I had an adequate ground.

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
post #10 of 14 (permalink) Old May 26th, 06, 01:26 AM
Senior Tech
 
Join Date: Jul 2001
Location: Pontiac IL
Posts: 453
Send a message via AIM to undee72Z
Re: Testing Gages

Quote:
Originally Posted by foreverlookin
The temp and fuel gages are fed from the same pink wire and prior and that voltage reads the same as the battery when disconnected from the gage. When I plug in the gage and read the voltage it drops to about 6.5V with the sending unit disconnected and when I reconnect the sending unit it drops again to around 3v. This is why I am leaning towards a gage issue.
If I am reading this correctly and you are testing the pink to ground with a meter, with the gauges hooked up....
Thats a huge drop. You must have a bad connection somewhere. Try using a temp wire from the battery for power (use a inline fuse for safety) You should still have battery voltage. Even the starter onlys pulls system voltage down 2 or 3 volts. I would bet the gauges will work fine with good power.

Greg U

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
undee72Z is offline  
post #11 of 14 (permalink) Old May 26th, 06, 04:48 AM
Gold Lifetime Member
Jim
 
Join Date: Dec 1999
Location: Yorkville, Illinois USA
Posts: 22,121
Re: Testing Gages

what Greg said
! If those were good reading, you seem to have a high resistance connection in the pink wire. Strong possibilities would be the console connector and the fuse utself.





To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
New website for my vert is coming together. Do ya like the slide show on the home page?
JimM is offline  
post #12 of 14 (permalink) Old May 26th, 06, 11:07 AM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

I am getting real confused here.

I have 12v on the pink feed to both fuel and temp circuits. When I plug the pink power onto the fuel gage the voltage through the gage drops to 6v and drops even further to about 3.5v when I reconnect the sending unit in the trunk.

The voltage deviates big time, 50% when I plug it into the gage. The resistance is accross the gage.

I will run a power feed, fused, to the gage from a different source and try it to see how it works.

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
post #13 of 14 (permalink) Old May 27th, 06, 12:01 AM
Senior Tech
Brad
 
Join Date: Jun 2004
Location: Kauai HI
Posts: 644
Re: Testing Gages

[QUOTE=I have 12v on the pink feed to both fuel and temp circuits. When I plug the pink power onto the fuel gage the voltage through the gage drops to 6v .[/QUOTE]


Im getting the EXACT same reading on my repop gauge! I've tried every ground possible. We need to know what's the voltage across a "working" gauge. I have my mouse on a buy it now button for a new temp gauge. Hope someone can chime in.

Most recent 01/01/10


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
spideynut is offline  
post #14 of 14 (permalink) Old Jun 12th, 06, 07:15 PM Thread Starter
Gold Lifetime Member
Steve
 
foreverlookin's Avatar
 
Join Date: Oct 2002
Location: Pflugerville, Texas
Posts: 1,764
Garage
Re: Testing Gages

Problem was old gages installed new ones and everything works fine...nice to know how much gas I have!

Steve
The best laid plans are those not made (mine)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
foreverlookin is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Electrical Problems with Floor Gages and TACH SS468CAMARO Electrical & Wiring 7 Mar 18th, 06 10:47 PM
Console gages (temp/amp) not working? chedderboy Electrical & Wiring 5 Jan 18th, 06 04:06 PM
Hybrid Testing 250 MPG Wayne Bench Racing 27 Oct 20th, 05 12:24 PM
68 camaro gages ks2kwik Troubleshooting 1 Mar 18th, 03 11:31 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome