Join Date: Jul 2012
Bronco Info: 91 Silver Anniversary
Are there any other differences between the harness? Might be easier to replace the sending units with ones made for that harness. I'm guessing here, but I'd believe the difference between the wiring is that one had the dash lights and the other has gauges.
Check the battery. What is it's voltage when truck is on? what is it off? Make sure the battery is fully charged then put a load tester on it to verify the battery is good. If all those test pass muster then you have a drain somewhere.
You could also just check for a battery drain by disconnecting the neg. terminal and getting a multi-meter set to milli amps. Put one lead to the battery and the other to the cable. WITH EVERYTHING IN THE TRUCK OFF!!! the amperage draw should be less than 0.9 If it's much more then there is something wrong.
5.8L, E4OD, BW1356
217,000 miles and rolling
Second... and Fourth Owner!