Honda Civic Forum - 1991 Honda Civic Main relay issue

So my civic has been in the shop for the past 2 months and the shop has been trying different fixes to sort out the issue but non has worked so far.

About 6 months ago my main relay stopped working ECU and Fuel pump does not come on. I searched around online looking at ways to be able to get me home and i did a by pass giving 12v to click over the relay. After buying the book that honda puts out to repair any electrical issues. The shop said the ECU has to be dead and another one has to be put in. So I give him a box of ECUs from that era all of them known that are working and I have already swapped the ECUs to check to see if that was the issue in the first place. I have checked the ING and nothing was wrong with that. so for 2 months I used a switch to be able to be able to get me to work and back. The shop told me that they don't know what would be causing the issue that the main relay would not turn on I( assume that they had followed the wire and the wire is good and it should be working. They decided to put a wire from the ING to the main relay and the wire started to get HOT. So the only thing that they could think of is that they needed to add a wire that is larger gague so that it would not get hot as quick. it has been really puzzling and I can not think of anyone else to ask about the issue. I have talked with the techs out of honda and they do not know what is going on. HGas anyone had this issue before?