124 a/c I KEEP PUTTING IN NEW PARTS

[PERFORMANCELSE]

1993 E300 4MATIC.I keep puting in new parts and my blower fan still will not run. I have put in a new dash controll unit, a new fan motor, check all the fuses and relays. I'm getting 12volts to the blower motor(red wire) when the inition is turned on, getting no reading on the blue wire at any time. I have check to power at the firewll plug, red at 12volts, gold at 3-6 volts depending on the setting on the fan speed setting. still no fan. I give-up. I'm tired of writting checks.