My son has a 70 SS. It had a dash with lites. He changed it over to dash with gages. He bought , new gages, printed circuit, wire harness, and had replaced the engine, and front wire harness , about a year ago. We finally put it in today. When we put power to it to check every thing, here is our problems. The temp gage pegged to 250 above and stayed, we took it of and pushed it back to 0, and tried again,and started to do the same, disconect the wire on sending unit and stop. The sending unit is new also. Also the Amp gage, goes the wrong way, - instead of +. He Also has a HEI, and the tach does not work. There may be some things you have to do different on the tach with HEI? Any help would be great. Also when he bought the new gages, it came with some instructions, that said you must take the resistor off the fuel gage and put it on the temp gage up and down which we did. Any Ideas? Thanks

Hi
I'm in the middle of doing the same swap.The issue and correction of the amp gauge problem can be found here.http://www.ss396.com/pdf_catalog/tech/dash/dash_amp_gauge_instructions.pdf

As far as the temp gauge did you change the temp switch to a gauge type from the light style switch.
I don't have gauges in yet,I pulled Malibu dash out yesterday and got wired up enough to get started so I can move it in and out of the garage.I'll follow this thread to see if I can share any problems or cures.

Just got home. We solved the problems. Not sure exactaly where the problem was on the temp gage, but we had some ground problems, and we change the resistor from another gage and it worked. The tach was a aftermarhet one, the factory uses a rivot to ground the tach. The new tach had threaded nut, and my son did not put a nut on the one post, which is a ground post to the gage. And last the Amp gage, which I do so offen is it must have been something we did wrong, not that the the new product could have a problem. The new wire harness they had the two wires backwards in the spot that plugs into the printed circuit. Sure felt good to find the problems. My son sayes it was one of the hardest things he did to the car so far, we had the dash in and out about 3 times, but it looks nice compared to the one that was all hacked up buy other owners. My son was young when he bought the car, but he learned that buying a good car that is correct and nice, is sill cheaper in the long run.