Oil and Temp light flashing together.

Hi all,
ive recently bought a Mk1 Golf with a 2l block running injection.
The Temp light and oil light both flash, it runs fine and doesn't overheat, temp gauge works and never goes above half.
MOT is in a few weeks so want to get this sorted.

am I right in thinking its a dodgy switch/sensor? Or it's been wired up wrong perhaps? Seems strange for them both to be flashing together!

many thanks

Hi all, just had another look at this in the rain…

I can't find the source of the problem.. Could it be something to do with the digifant expects a MFA computer? I'm still on MK1 clocks? I have no idea, I'm new to water cooled VWs over 1300cc!! please help, or I'll supply someone with tea and biscuits if you fancy lending a hand lol

the temp light also warns of low coolant on some models, check for a 2 pin sensor in the top of the header tank. if there is one check fluid level and if good remove the sensor and clean the tips of the probes. if that doesnt help bridge the pins on the plug. if that doesnt help check the fusebox, if there is a 42 or 43 relay above pull that out this will disable the fluid level warning.

as for oil flashign this is controlled by the pressure switch in the side of the head, to start with check the wire to it is connected and look inside the boot for damage. check its the correct type as well, if genuine vw one it'll be blue or brown, if not genuine or wrong colour VW sell them cheap

try disconnecting the wire this should stop the flashing, just dont let it earth anywhere. if that works then you know the clocks and wiring is ok

if pressure switch and wire are ok it may be you have low oil pressure to the head, this can be caused by worn cam cap bearings

Hi rub,

So the weathers been crp all week.
Had a look this morning.

Oil Pressure is fine, water level is fine( though it has a leak I'll be fixing)

My header tank doesn't have any plugs on it, though I found some spare connections near the tank. Bridging these didn't help.

Right, so I disconnected the wire on the head, still flashes, then there seems to be another on top of where the filters screws in, disconnected this also, light still flashes.

It's strange because the water light comes on after about 15secs of running, and the oil light shortly follows, of not as soon as the car is revved off it goes. Had the buzzer on too, but that was only for 2 start ups, that stopped while the car was running….

It must be a wiring issue, or my father told me the circuit birds can develop hairline cracks and this makes the lights play up?

Cheers Max

And no 42/43 

ok the coolant temp sender would be next on my list, they can fail in such a way that light flashes yet temp reads normal. the coolant temp sender is the one in the front or side coolant flange, its a red/yellow wire to a black sensor 1 or 2 pin depending on the age of the car.

the oil temp switch for the light at idle is the one in the side of the head with a yellow wire, try earthign the wire see if light goes out.  this switch should be blue or brown. the one in the filter housing should be white with a blue/black wire.

you can only go by colours if the pressure switches are genuine, if pattern I would bin and get new from VW as they're only cheap

Hi buddy,

Thanks again for the reply.

Earthing the oil pressure wire stops the light flashing, so I've order a new switch.

And I've order a new temp sender too.

I'll let you know how I get on.

Give me a flat four anyday