Guage Issues.....

[wldside]

Having some guage issues on my 69 Charger........ Just installed the engine and I pulled the coil wire and cranked the engine for about 8 seconds, waited a bit and cranked for another 10 seconds to get oil pressure up..  At no point did the oil pressure guage budge.  The Fuel guage is burried to the left as well and I put in 3.5 gallaons in the tank. I would think that when I turn the ignition on I should see some movement in the needles.  A couple of times the temp guage slowly pegged to the right.  Here's the list of things I tried. Some of them were from reading the Charger manual and others from reading online.  I have to say though, I am at a loss.....  As a side note, I had the whole instrument cluster rebuilt about six years ago and this is the first time I have tried to get them to work.
1.) checked the continuity from the engine side oil sending wire to the wire to the instrument guages...... Checked Ok
2.)Ohmed out the sending unit, resistance increased as I cranked the engine.
3.)Checked for 12V going to the guages, and took a test light to the Voltage limiter......  seemed to be getting juice.
4.)Tested the voltage limiter by removing it and wiring a ground wire to the top and 12V to the middle prong.  Bottom prong read iratic with a DVM.  It would read 2 to 6 to 4 to 3v........... Hooked up a test light and it flashed slowly.
5.) I checked the new fuel sendig unit before I installed it, seemed to ohm out OK.  I took the fuel sending wire to ground tonight and saw nothing change on the guage.
6.)Took the test light to the temp wire in the engine compartment and to ground while the ignition was on, it flashed slowly. 
So I am not sure if I have a bad voltage limiter, even though it is brand new from Year One.  The guages were rebuild by a guage shop.....
If you have any ideas, I am sure up to try anything...
Thanks, Dave

[Dino]

I don't think the gauges are supposed to go up until the engine is running.  Cranking it doesn't do much to my gauges.  Be aware that they can only take up to 6 volts, anything over that will fry the gauges.  Is your new voltage limiter solid state or original?  If the latter, get rid of it and buy a solid state limiter like the IVR4:  http://rt-eng.com/rte/index.php/RTE_limiter.  If this one would fail it'll cut power to the gauges, if an original type fails it'll send 12 volts to the gauges and they will be done for.

[Paul G]

Make sure you have a good ground on the engine to the bat negative terminal. Make sure the engine has a wire grounding it to the fire wall. With the ignition key on you can ground each sending unit wire. When the wire is grounded the corresponding gauge should go to full scale. This will work on the temp, oil, and fuel gauges only.

You say you had an oscillating voltage at the sending unit wire when testing it to ground. That is correct. Make sure you have that voltage at each sending unit wire. The stock type instrument voltage limiter is a "chopper" type device, meaning it pulses out the 12 VDC at timed intervals to get something closer to a pulsed 6 volts. A test light or an old fashioned analog meter is a better tool to check for that voltage. DVM's will just be jumping all over the scale, it is pulsed voltage.   

If you have the voltage at the sending unit and the gauge does not move when the sending unit wire is lifted and shorted to ground (BAT-), problem is in the gauge.

[wldside]

Thanks for the help.  Just ordered a new RTE limiter and am sending the guages back in to the shop.  Thanks Again, Dave