Hey guys. I have a 2005 F350 but I am posting this here because I am wondering if any of you 7.3 guys have the isspro performax gauges and have ever heard of the issues I am having with mine.

After I bought the gauges they worked fine for maybe 6 months. At that point they would sometimes freeze, sometimes they would jump around erratically, other times they would be reading way off like reading 50 PSI of boost or 1400 F exhaust temp at idle, a few times the gauges were not working but if I turned my lights on they would start working. The most common problem I am having though is the gauges wont turn on. When I turn my truck on the needle wont come up off of the stop. Also the lighting on the gauges wont come on either. I spoke to Michael a few months back and he had me check some voltages on the ESP. In the end he said it sounded like a broken solder joint in the ESP and sent me a replacement. I installed the new ESP and the gauges worked fine for a couple months before they started messing up again.

I am determined to figure this out so today I drove around with a multimeter to check voltages when the gauges were working and were not working. I found out that when the gauges are not working I only have 0.5V at the orange wire that comes out of the ESP and goes to the gauges. But when they are working I have 6.5V. Nothing else changes when the gauges are working or are not working. Can someone that has the isspro perfomax gauges please go out to there truck whenever they have time and measure the voltage at the orange wire from the ESP to the gauges. You can either do this by backprobing the orange wire on the gray connector of the ESP and measuring voltage between that orange wire and a good ground. or by pulling out one of your gauges and measuring the voltage between pin 1 which is the orange wire and pin 3 which is the black wire. Also could someone please look at the gray connector on their ESP and let me know which color wires are where on the gray connector. I just want to make sure I have all the wires in the correct locations. Thanks alot.

 

Normally I see 6.3v on the orange wire. You need to get back with Michael, he is the brain behind them and knows them better than anyone.

http://www.isspro.com/installation/IS149.pdf

 

Today while my gauges were working I measured 6.5V at the orange wire. Clearly that is normal voltage since you normally see 6.3V.

But while the gauges were not working I was only seeing 0.5V. I think I have found out my issue. Now I just need to find out why I am only seeing 0.5V at the orange wire sometimes.

I have already send Michael a email. Hopefully he will get it and reply to it tomorrow.