I am trying to figure out why the low hydraulic pressure light is not coming on in my GS. I replaced all bulbs on the dash and confirmed I now have choke, defroster, hazzard, turns lights etc. The light with the -| |- symbol and the one with a brake pedal symbol wont light at all.
The switch is most likely bad, but it also seems like the wiring is messed up. Grounding the wire that goes to the pressure switch does not light anything on the dash. Grounding the LHM level sensor lights up the oil pressure and oil temp lights (they always light and go out together when starting the engine). Pressing the test switch also does not light anything.
Is there a normal failure mode? a shorted diode would be my first guess, but I fid not find anything like that back there.
Car is a 1978/1979 GS Club with round dials and tachometer and voltimeter.
GS security valve and pressure switch lights
Moderator: RichardW
Sounds like you've got something funny with the wiring - triggering the low LHM level sensor shouldn't be lighting the oil pressure and oil temperature lights!
The low LHM float level contacts and the low pressure switch in the security valve are wired in parallel to operate the same light...(check the owners handbook if its still with the car
)
Regards,
Simon
The low LHM float level contacts and the low pressure switch in the security valve are wired in parallel to operate the same light...(check the owners handbook if its still with the car
)Regards,
Simon
Simon
1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White
2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White
2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
The safety valve pressure switch is a simple chassis connected switch. The switch terminal should be chassis connected when the car has stood for a while and pressure has fallen below 100bar.
Chances are the complete instrument cluster has been replaced over time, thus part of the wiring does not match.
Taken from the old haynes manual (non-spanner ratings) it seems the GS range came with several different instrument cluster layouts over its production time.
From sad experiences with the CX I know that the old style safety switch - with round switch connector terminal - can disrupt in this round terminal itself on the switch.
Any later style/model safety switch (with spade connector and plastic extension housing for the spring) however is a direct replacement.
They all switch at 100bar.
Chances are the complete instrument cluster has been replaced over time, thus part of the wiring does not match.
Taken from the old haynes manual (non-spanner ratings) it seems the GS range came with several different instrument cluster layouts over its production time.
From sad experiences with the CX I know that the old style safety switch - with round switch connector terminal - can disrupt in this round terminal itself on the switch.
Any later style/model safety switch (with spade connector and plastic extension housing for the spring) however is a direct replacement.
They all switch at 100bar.
Anders (DK) - '90 BX16Image