Fuel & coolant lights not working

[Traindriver69]

Hi all
On my TR7 the low fuel and coolant light are not working I have checked the bulbs and they are working.
Any ideas?

[littlepippin]

I'm not sure about the fuel circuit, but the coolant I think there should be a wire connected to your coolant reservoir tank, if not it may be dangling down somewhere below amongst the headlight wiring (mine was). Inside the water tank is a metal probe that relies on water being around it to complete a circuit to ground through the tank (so I guess you may also need to check the bolts are not too rusty and can make negative earth).

If you find the wire you could just ground it to the body/engine somewhere to check the circuit.

Sean.

[FI Spyder]

The low fuel light: there is a third wire connection at the sender by the gas tank, there is the sender itself, there is the wiring to the instrument panel (broken wire/bad connection on either end), there is a delay module on the back of the instrument panel (with it's connections) that prevents the light from flickering on and off when you get to that level and the gas is sloshing around in the tank. Without looking at the diagram I believe if you ground the wire at the sender that goes to the low light it should come on. It it does it's a sender problem. If it doesn't it's a wire/connection/delay/bulb problem.

[Traindriver69]

Sorted the coolant light out it was the sensor under the dash just the fuel one to sort.

[supercass]

I understand that the ethanol in fuel tends to destroy the contacts in the original sender units. My car was in dry storage for some years prior to the use of ethanol content fuels and when recommissioned the fuel sender was working fine. A few gallons of petrol later it wasn't. Coincidence perhaps but I think otherwise. supercass

[FI Spyder]

After cleaning my sender unit to get a bit of rust off it, it was a bit iffy when putting a meter on it. I put it in anyway thinking I could change it out later as it was close to time to put it on the road (spring). It worked great in tank after gasoline was put in tank. I use regular gas (10% ethanol around here) for last 9 years and it has been reliable and accurate ever since. I've just recently been using mid grade gas (5% ethanol). Ethanol hasn't affected it (at least in that concentration).