Low Fuel Light

[sixt9x33rs]

My low fuel light will not illuminate. I grounded the yellow wire under the dash to ground and it illuminated. I moved the wires around on the module trying to find a cold solder joint but no luck. How do I fix this problem? New module?

[69pace]

A simple Potentiometer can duplicate the Ohm's needed for the module to trigger the ground. Typically 10 or less. Twist up and down to makes sure it goes on and off.

Or without the trip to RadioShack just trick the gauge into seeing zero Ohms. Do this by disconnecting the lead in the trunk from the fuel tank sender unit, then ground the connector that runs forward to the gauge. Your gauge will peg empty when you power up, and if the module is working it will trigger the ground and light the FUEL light.

If not chances are the module is dead and you can replace with factory style, or a variable that you set the trigger point so it can be a bit higher then the typical 1/8 tank.

Attached is the design of the original modules from a thread I started a few years back over at Team Camaro. Lots of tips and tricks in that thread to customize your trigger point.

[sixt9x33rs]

I grounded my fuel gauge as 69 Pace suggested, and I did not get the low fuel light to come on even though the fuel gauge grounded to empty. I guess I need to replace the module if I can't repair it?

[69z28302]

69 Pace is great on these issues. He helped with my fuel module which turned out to be bad.

Mike

[sixt9x33rs]

Any further suggestions 69 Pace?
Thanks

[69pace]

Well 69 troubleshooting wise you have isolated the issue. You have tested that the direct ground of the FUEL warning light yellow lead lights the bulb. So the bulb and wiring are in good working order.

And direct grounding of the lead at the sender connection in the trunk - which sends zero ohms to the gauge and the LFWM at the same time, while sending the gauge to empty and beyond failed to light the bulb. So you have proved that the gauge can see below the factory set point and should be triggering the module to ground.

So that leaves only a few possibilities, either the LFWM wires are loose on the rear of the gauge, or the yellow connector to the light is loose, or the module is dead.

You can check the yellow lead of the module for ground with a meter if at zero ohms the yellow doesn't ground it is the module.  I willing to bet it is the module and you might just cut to the chase and buy a new one.

Factory style replacements are available through Classic Headquarters and American Auto Wire - both versions resold through all the big box Camaro stores on-line, The Classic HQ version has original design with the mounting fingers at the top to secure the module in the hole of the gauge plate. The AAW version is smooth top and you just zip tie the module to mount.
these modules seem to be standard around the 1/4 and below Ohms trigger point, but beware of some knock off's from China that are on eBay that are lower or higher set points, one reported as high as 3/4 full or as low as 2 Ohms which is like below the standard fuel sender intake sock.


$56.95 http://secure.classichq.com/68-69-LOW-FUEL-WARNING-MODULE--P851C62.aspx

You can invest a small amount more and get a variable set point so you can dial in when the light goes on.

These are made by M&H Electric Fabricators, Inc. 13537 Alondra Blvd. Santa Fe Springs, CA 90670  Great products, made in the USA but Crappy Website. Actually that is being kind, as it is one of the worse website designs I have ever used. So I'll help you out here with a direct link to the Camaro catalog PDF http://www.wiringharness.com/PDFS/CAM_2012_Camaro.pdf  The family of Low Fuel Warning Modules are on the bottom of page 16 as noted below:  

37651 1967 replacement "adjustable" low fuel warning module $59.00
NOTE: includes instructions, 06457873 lens & wiring to replace original "non-adjustable" console gauge mounted low fuel indicator unit

37651 1968 replacement "adjustable" low fuel warning module $59.00
NOTE: includes instructions, 06457873 lens & wiring to replace original "non-adjustable" console gauge mounted low fuel indicator unit

37651 1969 replacement "adjustable" low fuel warning module $59.00
NOTE: includes instructions & wiring to replace original "non-adjustable" console gauge mounted low fuel indicator unit

Don't know what 37651 looks like because there is no picture of the specific module listed for 67,68 and 69 but find it interesting that it is the same part number for all three years since 67 LFWM's sent power down the yellow to light the bulb and 68 and 69 grounded the yellow. In any event the "All Generic Adjustable" unit listed for one dollar more below is what I have used in other projects.

500274 ALL generic "adjustable" low fuel warning module $60.00
NOTE: a complete electronic control unit to activate a warning lamp or relay when fuel level drops below a user adjustable level



The big selling point here is that in 1969 there were four gas stations on every corner in every town and 20 gallon tanks and our expected MPG allowed us to wait until the 1/8 tank level to trigger the light. Today it takes 1/4 to get to the station. Set this module where you want the light to go on by Ohm's value, 1/4 to 1/2 are common.

So part number 500274 gets my vote until someone shows me the 37651 module. I would also Call them direct to order(562) 926-9552 since the website is quite the nightmare and only submits the order you have to call them anyways with payment information.

Happy New Year.
Brian

[262jp]

Be sure wires from module are connected correctly. Someone had the red and green crossed on mine. I switched them and now it works.