[T3] E C U Units

[Tim Keohane]

I finally found the link to the electronic components in my 73 FI. ( classicvw.org ) I checked my stash of electronic control units and see I have (1) 311 906 021 C ND (2) 311 906 021 D units. I'm looking for a 311 906 021 E to match my car and "stash" as a spare. The three I have I will move on, if anyone is interested let me know. I do not know how to test the units other than install them which I have not done. Any suggestions?? 
Thanks Tim 73 FI auto.