cobra460jet 10 Report post Posted March 17, 2012 Just redone my instrument cluster. Installed new led lights, lenses, paint the needles, new circuit board, and new ivr. Installed in car all lights work great. My gas guage goes to full. Theres no gas in new tank. Pulled off the wire to sending unit and guage still reads full with wire not grounded. Chk wire with ohm mtr shows 80 ohms with it grounded. When I put the instrument panel in the first time I hit something that shorted out and blew the instrument fuse. Put in a new fuse all works good but gas guage. I grounded the wire to the temp guage with a test light and nothing happens. Did I just short out my IVR that was new? Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 18, 2012 I checked my new ivr with an ohm meter and its dead. Installed a known good but old oem ivr. I grounded the oil guage wire with a test light and it works. The test light flashes on and off telling me the ivr is working. When I connect it to the temp wire its completely dead. Nothing moves or lights up. Quote Share this post Link to post Share on other sites
miketyler 15 Report post Posted March 18, 2012 So gas gauge is working now after you replaced the IVR? Did you check continuity between the poles on the temp gauge? I will be installing my gauges here soon and am interested in what you find out here Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 18, 2012 Nope gas guage doesnt work. Still pegs out at full. Im going to pull the istr cluster back out today. Quote Share this post Link to post Share on other sites
prayers1 153 Report post Posted March 18, 2012 I have the opposite problem, so I'm interested as well on how this works out. I installed a new Circuit Board, constant volt reg and a new sending unit and my gas gauge reads empty, and this is the only gauge I'm wanting to work since my others are mechanical. Please keep us posted! Quote Share this post Link to post Share on other sites
dennyb68 11 Report post Posted March 18, 2012 Make sure the studs on the gauges dont short to the gauge housing..They could twist just a little when tightening the nuts.. Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 19, 2012 I have the opposite problem, so I'm interested as well on how this works out.I installed a new Circuit Board, constant volt reg and a new sending unit and my gas gauge reads empty, and this is the only gauge I'm wanting to work since my others are mechanical. Please keep us posted! Pull the wire off the sending unit and ground it. If the guage swings to full then your problem is in the sending unit. Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 19, 2012 Make sure the studs on the gauges dont short to the gauge housing..They could twist just a little when tightening the nuts.. I took the guages out. They sit inside a plastic piece. Then the studs go into the metal housing. The plastic piece stops them from touching the metal housing. Can you actually tighten the stud so much that it twist it and damages it internally? Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 19, 2012 checking ford and mopar temp, fuel and oil pressure gaugesduring the classic car era ford and mopar gauges where produced using ni-chrome wire windings inside the gauge that would cause 2 terminals to expand or contract during the gauge monitoring process. There is one basic way to check these gauges. However, this method is only about 90 percent accurate. Get a good volt ohm meter and switch to the r times 1 scale and attach your leads to the 2 studs coming out of the gauge. It should read around 1o ohms, plus or minus and most likely the gauge is good. However, this method is ninety percent accurate . Other factors include the shape of the ni-chrome wire windings in the gauge itself. Alternator gauges in ford and mopar use a different setup and can be checked by applying a large d.c. Power supply across the 2 rear terminals. When applying 12 or 13.8 volts across the alt gauges 2 rear terminals (just tap it or your test leads may start to smoke:) the pointer should jump and the alt gauge is most likely good. Tachman can repair and calibrate most of these gauges with a 2 year warranty! H&h auto can also provide a free evaluation of your gauges to make sure they are operating properly. Quote Share this post Link to post Share on other sites
cobra460jet 10 Report post Posted March 25, 2012 I found my problem... The temp and fuel guages were grounding out on the metal housing. I took some electrial tape and put it on the backside of the guages to keep them from touching. Everything works just fine now. The way to check this is to get an ohm meter. Disconnect the IVR. Take one test lead to the metal housing. Take the other and touch it to each guage post. If it shows continuity or beeps like mine theres your problem. Its always something simple.... Quote Share this post Link to post Share on other sites
TexasEd 188 Report post Posted March 25, 2012 Glad you found it. Quote Share this post Link to post Share on other sites
relic1864 10 Report post Posted March 27, 2012 I had a time with my guages too. Then I put the electrical tape on and thats what it was. The guage was touching the metal. Its very hard sometimes to get the guages set just right so they wont touch and ground out. I still have my amp guage and oil pressure guage to get working but scared to try again now that my gas guage and temp guage works. Quote Share this post Link to post Share on other sites
Mister69 10 Report post Posted March 27, 2012 I bought these guage insulators, they worked great: http://www.virginiaclassicmustang.com/69-73-INSTRUMENT-GAUGE-MOUNTING-STUD-PLASTIC-INSULATOR-P2724C3410.aspx Quote Share this post Link to post Share on other sites
