14 pin dash connector - wire trace back

[Midge]

Hi Folks, would someone be able to help with this?

I've grounded the HP oil sender to Earth, to kill the buzzer-of-delight, but the damn thing keeps on buzzin'. The problem is that the Earth I'm sending from the back of the van simply isn't reaching the connector block up front.

I actually expected the block would be fine and the dash PCB would be the problem, but there's no continuity from the sender to the connector, I'm sure of it.

Tried to follow the yellow wire back from the dash connector and it's in with a million other wires in a real thick loom - I *think* it traces back to the bright yellow connector block on the back of the Relay Board?

Please could anyone confirm this, and also confirm how the wire actually enters the Relay Board from the rear sender, assuming it follows that route to the dash...

Worse case scenario I may have to run a fresh wire all the way from rear to front - unless there's a factory spare I can piggyback, like the Heated Rear Window I don't have?

Cheers for listening!

[bigherb]

Yes it goes through the fusebox it goes in from the engine at plug E terminal 15 and comes out to the instruments at plug B terminal 21

[Midge]

Have dug a little deeper... The yellow wire in the yellow connector block (behind the relay board) is not the HP oil press. wire on the dash connector.

But the yellow wire in the big red oblong connector block (also behind the relay board) is the correct one, jolly good!

Sadly I'm still no closer to understanding the back of the relay board - so have no idea how the sender wire enters the board from the rear of the van. I have this to go on:



...and my continuity test agrees with plug B heading off to the 14 pin dash conn. but none of the other plug descriptions suggest 'sender wires from engine compartment' to me

Main Wiring Harness connector sounds most likely ?

[Midge]

Yes it goes through the fusebox it goes in from the engine at plug E terminal 15 and comes out to the instruments at plug B terminal 21

Fantastic, cheers matey. I'm trying to get good continuity as far back to the rear as I can before I have to chop in a new section to the sender. Do you know if it's accessible in the big plastic 'black box' mounted to the engine bulkhead, I haven't poked a stick in there yet...

[bigherb]

. Do you know if it's accessible in the big plastic 'black box' mounted to the engine bulkhead, I haven't poked a stick in there yet...

yes

[Midge]

Okay I had good continuity from the dash connector back to the junction box on the engine compartment bulkhead.

Found a broken wire from the junction box to the pressure switch - yellow wire = 0.9 bar oil pressure switch.

Made a repair with a spade connector so I can easily run the wire to Earth (force buzzer OFF) or leave it Open (force buzzer ON) or hook it to the pressure switch as per the norm.

I'm still getting buzzed (except when forced OFF) - will run a pressure test when the replacement switches arrive, so I can replace with new ones after running the test.

Something still niggling me about the DOPWS - I only ever get a flashing oil light, and I thought I would get a static one under some circumstances? Mine flashes as soon as ignition key gets first turn (ignition on, engine off) and only stops flashing (turns off) when the engine starts up. Then it stays off until the BOD kicks in at around 2000rpm at which point the flashing light returns. This is the case with the switch wire running to any of the 3 options - Normal/ON/OFF - and with the other (0.3 bar) sender in the circuit as normal.

My owners manual says the light should flash so it's in keeping with that. Just thought I'd read something different somewhere, but I may be looking for a glimmer of hope...

So... Could be the switch is broken or maybe it's above 0.9 bar spec so is coming on early? Could be the 'computer' not reacting correctly to its' inputs? Could be genuine low pressure. Fingers crossed then...

[Midge]

WooHoo It's all good!

Hooked up the pressure tester to the low pressure take-off and got a cracking 1.5 bar on hot idle, running up near 4.5 bar on full chat - better pressure than I expected and well above the buzzer threshold. The buzzer/light were both giving it the full false alarm while the pressure was well over spec, so I'm well chuffed

Put a new LP sender in when the tester came out. Moved onto the high pressure take-off...

Got the exact same spiffing results from here, jolly good, and also discovered a rather ratty looking ancient HP sender with green gubbins on it, like an electrical failure had occurred. No doubt related to the lack of continuity in the sender wire I already swapped out, earlier. So... back in with the shiny new sender, fingers crossed....

Ain't heard the buzzer yet! Yippiddee Skippiddee, got me a good bus after all, yay!

Some sort of short down the sender wire had knackered the sender and burnt out the wiring, causing permanent 'buzzer on' so the nice man that sold me the van had disconnected the dash pcb warning light connector, killing the light/buzzer in entirety. Clown.

Anyways, I do like a happy ending