All the harness is doing is routing the power the same way the old harness did. If you're using the same original gauges/cluster, you'll still need an IPVR or equivalent. You'll have to figure out which wires in the EZ harness need to be patched into which pins on the instrument cluster connector and plug in a new IPVR in it's original place. I bought an EZ harness too, just haven't installed yet. Unfortunately mine didn't come with Ford connectors, only GM and universal. I'll be patching in the Ford connectors where appropriate. Since I'm installing aftermarket gauges in an F600 bezel, I'm not faced with your dilemma though.
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.