Bullseye240
Member
I recently added one of these "Optical Sensor Filter Harness" to my truck,I say added because I couldn't find one to remove in order to replace it. Since it has been in place the truck has randomly thrown codes 15 and 48. Last night on the way home it would randomly downshift from O/D at 45 mph and currently only has code 15. The first time it threw both codes was right after installng the "filter harness" and O/D wouldn't work. I immediatly figured since I had moved the engine harness around so much I had managed to break some wires or something since both sensors failing at once seemed unlikely to me. I found another engine harness from a donor truck and installed it above the manifold and the problems went away till yesterday (ambient air temps in the mid to low 40's to mid 50's). I understand why it kicks down out of O/D to heat up the engine because the ECM is told that the coolant is cold (makes sense, diesel engine cold add fuel and therefore produce heat). My problem is why has this started since I installed this thing to correct a stumble/stall problem which it still has and I traced to a bum lift pump and will replace this weekend with Turbine Docs prefilter/FRB pump setup. Same donor truck will likely donate its filter housing for a feed the beast mod. I checked the new harness before install and couldnt find anything resembling the "filter" anywhere on it. Is this thing some sort of scam or did 94's not have one and I just wasted some money on it? Love my Blazer:thumbsup: it just test me at times!!!!!:mad2: