Temp gauge issue with Audi engine conversion

[philyoung]

I’ve got a doka that has had a 2.8 30v Audi engine fitted (not by me). The temp gauge always reads in the red but an IR thermometer reads the block at a normal temperature. I suppose it might be a resistance issue between sender and gauge but I’ve no real idea. Anybody any thoughts on how to fix it? Thanks.

 

[Aidan]

Phil
so where is the sender for the water temp, and which sender is fitted ?
it may be possible to change it for one that matches the dash
If you disconnect the sender and earth the signal wire and turn on ignition does the gauge read full temp with flashing led ?
Pics might help

[philyoung]

It’s the Audi sender as it also sends a feed to the ECU. The led flashes soon after starting the engine but I’ll test as you suggest Aidan as soon as I can.