Oil Pressure Gauge
Oil Pressure Gauge
Author
Discussion

dannyboyo

Original Poster:

2,392 posts

308 months

Tuesday 27th April 2004
quotequote all
My oil pressure gauge hasn't been working for a few weeks now. I had the engine checked just to be safe and make sure it had some pressure and was fine, also the warning light goes off as it should when the car is started.

So I put it down to being the pressure sender, so I bought a new one and fitted it about 15 minutes ago but gauge still doesn't even twitch.

According to the bible, if it's a broken wire then the gauge will read high instead of nothing, so I'm ruling this out.

So does that just leave me with a buggered gauge then? Or is there something else I can check while it's up on the axel staands!!

Can I check the wiring from the sender? Does anyone know what route it takes?

Cheers chaps

Dan

verysideways

10,268 posts

301 months

Tuesday 27th April 2004
quotequote all
I don't want to point out the obvious, but have you taken the dash top off to make sure the guage is getting +ve and -ve feed?

Isn't it usually a third wire for the pressure (measuring potential difference between sender and battery to get reading of pressure)?

I guess there may be a couple of other wires for a bulb too?

VS

Sorry if you've done this already, just wanted to make sure. I've overlooked obvious things in the past (my cousin once told me to rewind the DVD before returning it to Blockbuster).

dannyboyo

Original Poster:

2,392 posts

308 months

Tuesday 27th April 2004
quotequote all
Cheers for the quick reply VSW, I haven't checked the actual back of the gauge, I was putting that off as by all accounts it's a nightmare of a job!!

But will go and dig out my 10mm spanner now!!

Thinking about it, it hasn't worked since it came back from having the wing repair and headlight upgrade, but I can't think how that could have affected it?

greenv8s

31,014 posts

313 months

Tuesday 27th April 2004
quotequote all
If you disconnect the wire at the sensor, you should find a voltage there. Also the gauge should move either when the wire is disconnected (infinite resistance) or shorted to earth (zero resistance). If these tests fail, you may have a faulty gauge or a wiring/fuse fault. Perhaps the headlamp work involved some fiddling around in the fuse box which has disturbed something?

UIL9794

268 posts

277 months

Tuesday 27th April 2004
quotequote all
Hi Dan,

You mentioned

'Thinking about it, it hasn't worked since it came back from having the wing repair and headlight upgrade, but I can't think how that could have affected it?

When i had my Chim, it went to the same garage for v.minor work and came back in a shocking state - had the AA out 3 times over the following few days.

Getting the dash top off to check the wiring isn't too bad to do, i might not have to remove it completely to see the wiring - it's more of a pain trying tho get it back on ok. Especially on your own.

Lee

dannyboyo

Original Poster:

2,392 posts

308 months

Tuesday 27th April 2004
quotequote all
An update:-

Got the dash off (phew!) and tested GND and +12V to the gauge and were fine. While the gauge was out I checked the wire from the sensor to the gauge and it appears bvroken. Just to confirm I ran another wire from the sensor to the gauge and it worked again!!

So problem sorted, just need to fix or replace the old wire now!

dannyboyo

Original Poster:

2,392 posts

308 months

Tuesday 27th April 2004
quotequote all
OK, another question. It now looks like when the front headlight conversion was done, and the new headlights were wired in, a loom was cut, and one of the wires in the loom was the presure sensor wire (green/brown). The bit at the sensor end is only about a foot long and I can't see were the other bit it should join up to is in the engine bay.

So, does anyone know the route the presure sensor wire leaves the dash, goes through the bulkhead and is routed through the engine to get to the sensor? If I can find the other end in the engine bay I can join them back up and it'd be sorted!

Failing that, it's a case of running a new wire from the gauge to the sensor.

verysideways

10,268 posts

301 months

Tuesday 27th April 2004
quotequote all
Glad you found it so quick db, i'd hate to drive my car without knowing the oil pressure was okay...

Good luck with finding your way around though, i think you may be best to follow the wire from the back of the guage and see where it pops out in the engine bay... (tech terms ON) give it a jiggle at one end and see if you can see it wiggle at the other end. (/tech terms)

VS

spend

12,581 posts

280 months

Tuesday 27th April 2004
quotequote all
From sender up into mesh loom over heads and down back of engine. At rear of engine just under middle of the big black ventilaition duct is a big grommet (battery cables & loom go thru here) which you cab just feel by reaching via bonnett lock under the duct. This comes out behind the stereo - take stereo out and you can see the big grommet. Loom goes up to multi connectors for the dash wiring.

Very conversant with this after wiring oil temp, cleaning up alarm installer mess & rewiring dash!

Let me know if you want any pics, just happens I still have dash off.

Dave

dannyboyo

Original Poster:

2,392 posts

308 months

Tuesday 27th April 2004
quotequote all
Cheers for all the replies chaps. I've got it sorted now.

After the ordeal of taking off the dash etc etc, I found that my wire is in the headlight loom that runs inside the n/s wing. Tucked underneath the radiator were three wires that came off the main loom, one of which was the other half of the bullet connector on the Green/brown wire. Connected it up and, wayhey, I've got a working gauge again.

I guess they forgot to connect it back up when thay did the headlight upgrade!

Well, thats one thing off the list!!

Cheers again