series 2 SIP speedo

Help please I have fitted a sip speedo to a TV 175 this is the second one as I sent the first one back due to a fault but low and behold the new one is doing the same thing the needle on the Rev counter doesn't move (before setting it up it did) but when I flick through the speedo the digital rev counter works. I have fitted a r type plug .I have fitted a few sip speedo's but never had this problem. Has this happened to anyone else and did you get it to work
I have ask SIP but got no where with them
Any help is appreciated
I have ask SIP but got no where with them
Any help is appreciated