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Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 9:24 am
by myoldjalopy
Wes wrote: Mon Apr 14, 2025 8:13 pm Red Ignition light works as expected/normaly
If, as others have suggested, the wiring to the lamps has got mixed up, then this would indicate the oil pressure is OK and that there is an issue with the charging system. It might be worth checking voltage output from the alternator to see if its behaving normally.

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 1:31 pm
by Wes
myoldjalopy wrote: Tue Apr 15, 2025 9:24 am
Wes wrote: Mon Apr 14, 2025 8:13 pm Red Ignition light works as expected/normaly
If, as others have suggested, the wiring to the lamps has got mixed up, then this would indicate the oil pressure is OK and that there is an issue with the charging system. It might be worth checking voltage output from the alternator to see if its behaving normally.
Across the battery terminals: 12.4V at rest. 14.2V when running. guessing thats pretty normal/ok?

To recap. Newish alternator (by the looks of it) & negative earth. Red light & yellow lights on as key turned. Red goes off on start up. Yellow dims/flickers on idle getting brighter as revs rise.

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:35 pm
by Wes
Wow you guyss were bang on. PO wired bulbs the wrong way around. Couldn't get to mounting screws to get speedo out but with drivers glove box out the way I could just get my hand in and swap the bulb holders. :D :D :D

So just leaves question that if fan belt is ok & reading across the battery terminals of 12.4V at rest and 14.2V when running. Why is the now correctly wired (green & white) ignition warning light on & flickering when engine running and revs up?

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:38 pm
by Wes
BTW thanks ever so much for the tip on crossed wires.

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:46 pm
by geoberni
So, what we have is a Red Ign Light that's behaving normally, so we can discount crossed over lamps and all the talk about Alternators etc.

On Monday you said:
Wes wrote: Mon Apr 14, 2025 5:20 pm Take wire off switch: yellow light stays on
- Touch wire to earth: yellow light stays on.
This was presumably with engine not running.
With the wire off the Sw, the lamp should be off.
So completely disconnected from the Switch we have a light on at all times and then when the engine is started and things are vibrating a little we get
Wes wrote: Mon Apr 14, 2025 5:20 pm Start car yellow light flickers at idle and gets brighter more constant as revs rise.
This makes me wonder if we have a chaffed/trapped cable that is shorting to earth and when the car is vibrating it's intermittent.
15 - Back of fuel gauge/voltage stabiliser
18/19 - Heater Switch and Blower
25 - Oil Filter Warning Light (presumably not fitted from what you've said)
26 - Oil Pressure Sw and light
Oil Light Issue.JPG
Oil Light Issue.JPG (34.34 KiB) Viewed 4331 times
So what you need to do is find the inline connector I've pointed out with the arrow, up behind the dash somewhere.
If there's no filter light, then there should only be 3 green wires in it, the supply from (15), the feed out to the Heater (18/19) and the feed to the Oil Pressure Light & Sw (26).
Being careful not to let anything touch the body, separate the connections and confirm which one has battery supply when Ign is ON; then continuity the other two to earth (one meter cable to the connector, the other to the chassis).
With the Heater switched Off and the cable pulled from the Pressure Sw, both should be open circuit.

See what you find....

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:47 pm
by Wes
Weirdly ignition light now stays on even when key is removed :-(

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:49 pm
by Wes
Yellow Oil light behaving as it should now

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:53 pm
by geoberni
Wes wrote: Tue Apr 15, 2025 5:47 pm Weirdly ignition light now stays on even when key is removed :-(
Now you've really confused me..... :roll:
Remote diagnosis gets so hard.....
Are you 100% confident that Lamp with Green/Yellow is in the Oil Light and the Brown/Yellow and White wires are on the Ing Light.

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:58 pm
by Wes
Yellow lamp now has Green/Yellow & green wires coming from it
Red lamp now has green & white(ish) wires

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 5:58 pm
by Wes
Let me look again!

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:04 pm
by Wes
Top right lamp which is yellow now has green & green/yellow wires
Botom right lamp which is red now has yellow and light beige wires

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:05 pm
by geoberni
Wes wrote: Tue Apr 15, 2025 5:58 pm Yellow lamp now has Green/Yellow & green wires coming from it
Red lamp now has green & white(ish) wires
That sounds right for the Oil light, Green one side and Green/Yellow the other .
The colours on the Red Lamp could just be discoloured with age, but should be Brown/Yellow one side, and plain White the other.
No Green anywhere on the Ign Lamp......

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:07 pm
by Wes
see update on wire colours:
Wes wrote: Tue Apr 15, 2025 6:04 pm Top right lamp which is yellow now has green & green/yellow wires
Botom right lamp which is red now has yellow and light beige wires
below

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:09 pm
by Wes
Wes wrote: Tue Apr 15, 2025 6:04 pm Top right lamp which is yellow now has green & green/yellow wires
Botom right lamp which is red now has yellow and light beige wires
Guessing the light beige could well have been white once

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:14 pm
by svenedin
Wes wrote: Tue Apr 15, 2025 6:09 pm
Wes wrote: Tue Apr 15, 2025 6:04 pm Top right lamp which is yellow now has green & green/yellow wires
Botom right lamp which is red now has yellow and light beige wires
Guessing the light beige could well have been white once
Before I changed my loom all the white wires looked beige with age.

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 6:15 pm
by Wes
bottom right bulb holder

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 7:44 pm
by geoberni
The Beige will be the White, the yellow is hopefully Brown/Yellow but the Brown is all on the far side of it. :wink:

But now we have this problem....
Wes wrote: Tue Apr 15, 2025 5:47 pm Weirdly ignition light now stays on even when key is removed :-(
All alternator conversions are a bit hit and miss, because it depends on the electrical competence of the installer....
If I were working on it myself, I'd be checking voltages here and there, but not knowing, or seeing, the exact installation it's hard to know where to start.

It doesn't make any sense as you've described it; when it was in the other bulb holder it wasn't on with the key out, so why is it on now just because you swapped it over...???

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 8:19 pm
by Wes
It doesn't make any sense as you've described it; when it was in the other bulb holder it wasn't on with the key out, so why is it on now just because you swapped it over...???
[/quote]


AARRGGHH :-)

Re: Oil Pressure Warning Light

Posted: Tue Apr 15, 2025 8:20 pm
by Wes
2 steps forward 1 back!

Re: Oil Pressure Warning Light

Posted: Wed Apr 16, 2025 10:11 am
by Wes
Well blow me. Tried the car this morning. Turned on battery and no lights! turned key and both yellow & red come on. start car yellow goes out but red stays on blinking/flickering. But still getting 14.2V at the battery??