1988 300e Blower motor

[GrecoSG]

Hi ,
I am having a problem with my sons 1988 300E with 110,000 miles. The blower motor wont turn on. I have used the search function and checked all the fuses etc. I have no 12V at the external fuse at all on either side of the fuse. The wires appear to go into the firewall. I have also read that the power for this fuse is wired in parallel from the #12 fuse in the fuse box. I replaced a ignition switch a few months ago to fix a no start problem. I checked the wires on the switch to make sure none popped of the terminals. I also verified that 12V is present at terminals 15 and 15R. Does the 12volts for the blower fuse go thru the ignition switch or direct from the battery. Its getting cold and i want my son to be safe with good defrost etc any help would be appreciated.

SDT