Td5 gauge

[Green200tdi]

After fitting a td5 loom to my 1986 110 I notice the plug to the sensor is ignition live soon as I put it on the one pin sensor it blows the fuse,

my engine is a 200 tdi what I’m wondering is if I buy a two pin td5 sensor does pin two go to earth or back to what would be the ecu ( no ecu used) 

[western]

I guessing your talking about the coolant temp sender ? 

as there is no ecu & your existing sender is earthed via the engine block, just run a single wire from the sender direct to the temp gauge signal in terminal, it'll work. 

IIRC on Td5 wiring the coolant signal goes via the ECU which tells the gauge to show the temp level

[Green200tdi]

4 hours ago, western said:

I guessing your talking about the coolant temp sender ? 

as there is no ecu & your existing sender is earthed via the engine block, just run a single wire from the sender direct to the temp gauge signal in terminal, it'll work. 

IIRC on Td5 wiring the coolant signal goes via the ECU which tells the gauge to show the temp level

Yes I was wondering if the live went to the engine temp sensor and an earth went to engine block as it’s two pins  or back to the ecu

I’ll run a new wire but really trying to keep to original wires 

 

[western]

The Td5 wire if you use just the light green/blue trace wire might work BUT the end terminal will need changing to suit the existing sender unit terminal. I'm not sure how the Rest of the world [last of the 300tdi's were wired as they used Td5 gauges but I suspect with the ECU. just direct to the gauge as far as I can see from my td5/300tdi wiring diagrams.

[Green200tdi]

I’m going to go back to the ecu plug see if I can’t follow the colours from there then bridge,

wire at sender to ecu plug then back up to dash, 

[Mo Murphy]

If you want the temp guage to work you will need a black 300 tdi sender and the wire needs to be routed via the resister on the TD5 speedo circuit board. Google is your friend with this.

You can wire it directly but you will have to experiment with different sized resisters to get an accurate reading. It's a tremendous ball ache which I did about 15 years ago.

The former way to do it is the way to go.

HTH

Mo