Blowers not working.

The blowers on my FR aren't working and I know it's a bit of an issue. I have climatronic and I have spent this evening checking voltages and outputs and they are all working. I have an open circuit in the resistor pack which is intermittent (the most frustrating type of electrical fault).

My question is this if I am ordering a new resistor pack does it matter what the letter is on the end of the part number or does this purely denote its current mod standard? IE I have a D can I fit an F?

Thanks

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