Water Level Sensor

[PhilNW 44]

Odd situation - Have a bottom mounted water level sensor . Ever time the engine revs above 3000 rpm the light comes, hot or cold.

Checked with cap off and water level does not drop when it reaches this rpm.

Tried the wiring not found any fault

Any ideas other then a dodgy sensor which are NFP.

Edited July 24, 2017 by PhilNW

[Anthony 1,003]

Noise from the ignition system can cause this - try moving the wiring as far away as you can from the HT leads and see if that helps.

[PhilNW 44]

The wiring has 3 wires but Haynes manual shows only 2

What do the 3 wires do?

[welshpug 1,661]

the 2 wire sender is the phase1/1.5 type which was a very simple reed switch, yours is a phase 2 type which was known to be susceptible to noise like Anthony suggested.

 

not sure how the later sender works but most level senders used by PSA from about 1990 on were 3 wire, most likely 12v, earth and a signal wire I would presume.

[PhilNW 44]

Noise from the ignition system can cause this - try moving the wiring as far away as you can from the HT leads and see if that helps.

 

Wires are against the bulkhead behind the header so cant get much further away.

New HT leads best bet or some form of shielding?

Edited July 24, 2017 by PhilNW

[pug_ham 244 3 Cars]

Wires are against the bulkhead behind the header so cant get much further away.

How close do your HT leads route around the wires or sensor though?

 

g

[PhilNW 44]

About 150 mm to distributor leads

[pug_ham 244 3 Cars]

OK, tbh most newer leads should be shielded to some extent so if your leads are quite old maybe a newer set will improve things but when I suffered this flashing water level light (only on the later expansion tank & sensor) I re-routed the leads for a tighter radius off the dizzy cap getting as much air gap as I could between them & the sensor and that fixed it.

 

g