Quad Gauges not Working ..... STILL!!

[chaps70rt]

a) 12V at the IVR  (Multi-Meter)
b)  5V out of the IVR
c)  all gauges tested for function with three AA batteries
d)  Check that the threaded posts on the back of the gauges are not touching the chassis of the cluster (grounding)
    Each gauge should have a non-metal gasket between the nut and chassis of gauges.  I even added some heat shrink to
    each post.  Confirmed.
 e)  Check the 4-post jumper from the IVR to each gauge for internal shorts. No Issue ..... 4.9V at the post.

HOW DO I TEST THE READINGS COMING OFF THE DASH HARNESS THAT CONNECTS DIRECTLY TO EACH GAUGE????

Failing that ..... I am out of options.    Will need to check all the other entries on this forum for other ideas.

AFTER 17 years of rebuilding this car, it is the last mechanical/electrical issue that won't resolve.   

Can't drive without OIL, TEMP, FUEL!!!!

[Bullitt-]

  Here is someone that was having a similar issue, resolution in his next post https://forum.e-bodies.org/index.php?msg=101908

  You never mentioned having the cluster body grounded.

  A simple check for the harness would be a test light or multimeter  connected to power on one side & to each of the wires from the sending units should show a completed circuit, glowing light or meter reading. If you get nothing ground the wires at the source, to eliminate the sending units, & see if you get anything. 

[chaps70rt]

Just to confirm .... I added a few ground wires from the back of the chassis and bundled them together with a spade connector and attached it to a bolt on the metal dash frame.

This afternoon I also swapped out the dash with an unmolested original 1970 rallye dash.  Same result.. three gauges don't work still, so that eliminates an issue with the gauges or mounting of the gauges.   Here is a picture of the back of my gauge cluster (with voltage gauge that works great) and noise suppressor removed. IVR is from RT Engineering (solid state).

Any other ideas of what I can check??

Gary

[chaps70rt]

Here is someone that was having a similar issue, resolution in his next post https://forum.e-bodies.org/index.php?msg=101908

  You never mentioned having the cluster body grounded.

  A simple check for the harness would be a test light or multimeter  connected to power on one side & to each of the wires from the sending units should show a completed circuit, glowing light or meter reading. If you get nothing ground the wires at the source, to eliminate the sending units, & see if you get anything. 

Here is someone that was having a similar issue, resolution in his next post https://forum.e-bodies.org/index.php?msg=101908

  You never mentioned having the cluster body grounded.

  A simple check for the harness would be a test light or multimeter  connected to power on one side & to each of the wires from the sending units should show a completed circuit, glowing light or meter reading. If you get nothing ground the wires at the source, to eliminate the sending units, & see if you get anything. 

Thx Bullitt .... I will try this test and report back.  Will try to do it this afternoon.....  Gary!!

[Bullitt-]

@chaps70rt Has your ammeter been converted to a volt meter?
  If not in my mind grounding it would be a dead short!

[chaps70rt]

Yes .... I eliminated the ammeter in favour of a Voltmeter (SunPro).  Red and black wires were soldered together and double wrapped with rubber shrink wrap.
New voltmeter works great.

[chaps70rt]

Just checked for continuity from the blue wire at the tank/sending unit all the way to the 90 degree connector that plugs into the gauge.   I have clean contact and continuity.

[dodj]

I'm thinking your dash frame is not grounded... run a jumper just to make sure it is.