I recently installed an LI Quad HPs on the front of my vehicle. From the very first day, I kept getting warnings that "Connection to sensors 2 are poor or bad" or the "Welcome" upon power up. The connection to sensor or welcomes were random with each cycle of the power switch. I called Cliff and he stated that I should check the voltage supplying power to the LI CPU. It was about 12.7 volts key on, engine off and about 13.5 volts with the engine running. I checked the power supply cables by wiggling wires and monitoring the voltage looking for intermittent drops but all seems solid.
With all sensors plugged into the cpu, I switched sensor 2 (the sensor giving the poor or bad error) into port 1 and now got the connection to sensor error on port 1. I then switched it from port 1 into port 3 and got the connection to sensor error on port 3. Hmm, okay, must be a bad sensor. Again, while performing this process of elimination, it would sometimes give the welcome message but more often than not, it was connection to sensor error. I figured it was probably bad wiring or the connection inside the head itself causing the random errors. I checked the plugs and all contacts look good.
I called Cliff and he stated that there might be interference but all of the heads will work regardless of the error unless it's giving me consistent connection errors. I bought a cheap laser head tester and sure enough even with connection to sensor voice alert, all of the heads respond to the tester. But are they firing? I took my video camera and each head activates while two purplish diodes illuminate. Even though the CPU dislikes that particular sensor, it seems to be working like the others. At this point, I was really baffled as to why switching the sensor into different ports still produced random warnings but consistently followed this particular head while continuing to function normally.
This weekend was the first time I actually drove the car for awhile from NY to PA and then back again. I pulled out of the garage, check the level on the heads, and powered up with a connection to sensor error after letting the engine idle for a few minutes to be sure battery voltage would be fine. I tested them again with the handheld laser tester (paranoia?) and got responses on each head. I got back into the vehicle and noticed the LED on the switch was off while the switch was in the on position. I reset the switch again and while powering up the LED light flickers followed by the connection to sensor error and then the LED goes dark. I thought it was power to the switch or bad connection to it that might be causing the issue. I reset it again and got a welcome with which the LED stays on. Another reset greeted me with connection to sensor followed by the led going dark. I got out of the vehicle, and used the handheld tester again which activated the heads. Now the LED is on solid.
So it appears that if you get a connection to sensor error, the LED shuts down until activated by laser or in my case the handheld tester putting the system back into operation. A welcome causes the LED to stay on. I haven't tested it by physically unplugging the sensor and testing the system to see what would happen. Also, I get the connection to sensor error about 80% of the time while powering up regardless if the engine is running, shut down, or driving.
The only thing I can think of at this point is some kind of interference where the sensor head wiring is routed or where the CPU is located. I was thinking of remounting the CPU somewhere else and running the sensor head wires temporarily outside the vehicle through the window to see if it reduced or eliminated the errors. If it turned out to be successful, perhaps some kind of sheilded tubing to route the wires in might be of some help. It's just that it took me awhile to route the wiring in nice protective convoluted tubing and making everything nice and neat. It would be a real letdown to rip it all out, do the experiment, and still end up with the same kaka.
I have faith in the system and that it will activate when needed regardless of the errors. But it's kinda like flying a plane while getting a stall warning in straight and level flight and with good airspeed. You know everything is fine.... or is it? I have to say Cliff has been awesome and calls you back right away. I still wouldn't run anything else despite the quirks.