87 mustang convert still not working

Guess you mean 'relay'... where ARE they? were they replaced?

HOW CAN YOU GET 13 VOLTS AT THE PUMP BEFORE YOU FLIP THE SWITCH?

is the pump a standard 3 wire model one wire goes to ground the other two are forward(up) and backward (down) or a two wire ( the current reverses at the relay). either way you shouldn't have power at the pump until the switch is pushed. keep looking

iI have power when the switch is engaged. it is the 3 wire configuration.pull the switch forward one line is hot ,push switch in the other line is hot .this plug is after the relays so its not the relays right? If it were the relays there wouldn't be power after them to the plug

The only thing that counts is if the power is there WITH the plug connected to the pump.

Short lesson in ohm's law which we dont have time for.. if you see LOW OHMS.. maybe one ohm.. on the pump side, then connect 'em and see no voltage THEN you have burnt relay contacts.

ok if you get reveserving current one wire hot at a time. check to see if the center wire is supplying a steady ground. do you get 12 plus volts from one wire to center or from the one wire to a known ground? if the plug just before the motor is providing both a 12 volt source and a constant ground without poping fuses the pump motor is bad. even if its "replaced" it could be defective.