IowaTom Posted November 30, 2021 Share Posted November 30, 2021 Guys - I'm not getting any response from the fuel or temp gauges on my '85 F150 with the inline six. As much as I'm not a big fan of under-the-dash add-on gauges, I'm not comfy driving around without an occasional glance at engine temp and remaining fuel. I'd like to get the proper impedance gauges for both and I'm hoping one of you has already been there and done that. :-) I'm a doltz when it comes to electrics. Is there a way I can figure this out with my trusty VOM? Thanks!! Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 30, 2021 Share Posted November 30, 2021 I'm not sure I understand the question. Are you wanting to diagnose your gauges or replace them with non-standard gauges? If your oil pressure gauge is working then so is the ICVR. If not, it is probably the ICVR that is the problem. If the ICVR is working you can put your trusty VOM on the wire going to any of the gauges and get a pulsing voltage. But a test light would be better/easier to see. Link to comment Share on other sites More sharing options...
IowaTom Posted November 30, 2021 Author Share Posted November 30, 2021 I'm not sure I understand the question. Are you wanting to diagnose your gauges or replace them with non-standard gauges? If your oil pressure gauge is working then so is the ICVR. If not, it is probably the ICVR that is the problem. If the ICVR is working you can put your trusty VOM on the wire going to any of the gauges and get a pulsing voltage. But a test light would be better/easier to see. Yes, Gary, I was going to use non-standard gauges for the fuel and temp. Dumb question: What's an ICVR? Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 1, 2021 Share Posted December 1, 2021 Yes, Gary, I was going to use non-standard gauges for the fuel and temp. Dumb question: What's an ICVR? ICVR = instrument cluster voltage regulator. You might be interested on our page at Documentation/Electrical/Gauges. That's because there's info on the ICVR, the wiring, and the gauges themselves on that page. See if that helps and then ask more questions. But I don't think you'll want to use aftermarket gauges. That's because the Bullnose gauges are not truly electrically driven. They are actually thermometers. Yep. There's a heating coil in each gauge that the current heats, causing the needle on the gauge to move. And the current going to the gauges is pulsing. The ICVR is not a voltage regulator at all. It simply chops the current to reduce the effective wattage to the heating coil. The result is a pulsing voltage that you don't want to use to drive electrical gauges. Link to comment Share on other sites More sharing options...
IowaTom Posted December 1, 2021 Author Share Posted December 1, 2021 ICVR = instrument cluster voltage regulator. You might be interested on our page at Documentation/Electrical/Gauges. That's because there's info on the ICVR, the wiring, and the gauges themselves on that page. See if that helps and then ask more questions. But I don't think you'll want to use aftermarket gauges. That's because the Bullnose gauges are not truly electrically driven. They are actually thermometers. Yep. There's a heating coil in each gauge that the current heats, causing the needle on the gauge to move. And the current going to the gauges is pulsing. The ICVR is not a voltage regulator at all. It simply chops the current to reduce the effective wattage to the heating coil. The result is a pulsing voltage that you don't want to use to drive electrical gauges. Gary - I've decided to replace the ICVR after reading your great page on it. I bought the Carpenter regulator and will update the post once I install it. Thanks so much for having an incredible trove of help on your website! By the way, I made a dual relay circuit for the headlights using your info. Love it! Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 1, 2021 Share Posted December 1, 2021 Gary - I've decided to replace the ICVR after reading your great page on it. I bought the Carpenter regulator and will update the post once I install it. Thanks so much for having an incredible trove of help on your website! By the way, I made a dual relay circuit for the headlights using your info. Love it! I'm glad the site is helping. It has been an effort borne from frustration over having to answer the same questions over and over. I finally realized that if we documented the solution once and then built on it over time it would help a lot of people. Apparently it is working. Hopefully the ICVR will solve your problem. And glad the relays worked well. Link to comment Share on other sites More sharing options...
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