P38A Spurious Failure Warnings

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DanClarke

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Benfleet, Essex
My 1999 P38 "Thor" 4.6 HSE is giving me further cause for concern.
Not content with returning only 10MPG she is now throwing up warning lights like Southend-On-Sea illuminations. The symptom is a cyclic clicking of a relay/relays with the appearance of the low-fuel and engine overheat alarm lamps and the seat-belt lamp in conjunction with this clicking sequence.
Took a look in the engine compartment fuse & relay box and I can feel Relay RL-7 changing over in time with the cycling of alarm beeps and the lamps. Took it out and its showing charring on several faces (HR and high current loads?) Swapped it over with another relay to see if it stopped the cycle. It doesn't.
No idea what to do next TBH. It's electrickery stuff. While I can still drive it, I can't trust it not to develop a shut-down type fault now. Any words of wisdom would be much appreciated.

Regards,

Dan.
 
I am with Wammers on that, fuse box you can get them new but make sure it's the correct one for your year and engine as there are a few to choose from., if you ask Wammers nicely he may give you the part number.
 
I am with Wammers on that, fuse box you can get them new but make sure it's the correct one for your year and engine as there are a few to choose from., if you ask Wammers nicely he may give you the part number.
Thanks Brian, Bay of E has some for this model year, but you don't really know what you are getting.
 
Thanks everyone.
Got a replacement (2nd Hand) on its way from the bay of E.
What further surprises me though is that today the battery is flat as the proverbial.
Whereas yesterday it was 12.75V just sitting there and 14.43V with engine running (which sounds about right to me).
Too complicated for their own good I think :(
 
If your fuse box is indeed faulty, then there will be things on that would normally be off, relays drawing current for no other reason than they are "on"

The fuel usage is worrying, but if the ECU "thinks" the engine is too hot or too cold, it will be in conflict and run rich...

Replace the fuse box and see if things settle down. I would suggest getting the codes read and deleted just to see if they return. If not, all should be good.
 
Thanks everyone.
Got a replacement (2nd Hand) on its way from the bay of E.
What further surprises me though is that today the battery is flat as the proverbial.
Whereas yesterday it was 12.75V just sitting there and 14.43V with engine running (which sounds about right to me).
Too complicated for their own good I think :(

You have got the generation 3 RF receiver?
 
You have got the generation 3 RF receiver?
Not sure. I have an LR original part that cost me a lot of money >£200 and was meant to cure the problem, will need to pull stuff around to check the part #.
Some weeks ago I removed the antenna lead because of mystery battery drain issues.
I am hoping that a replacement fusebox will set her right again.
Thanks for pitching in. :D
 
before you go pulling everything, check the battery. batteries these days are considered 5 year items and if it's been discharged sufficiently, it will be toast
 
Hi Adam,
Yes, it may not be a happy-bunny but its less than 3 years old with a Hal-Frauds 3 yr warranty.
they do a free battery condition check.

not saying your battery is on the fritz, but better to check then spending time searching for a gremlin that doesn't exist
 
Well, that was a bit expensive (£75 + P&P) and rather disappointing. :(
The replacement fusebox arrived this morning, I have changed it over and while it is all "char-free" with a full complement of un-burnt relays and shiny fuses it has made absolutely no difference to the situation.
As soon as the engine is running the cyclic clicking of relays begins and the low-fuel and overtemp alarms light.
As I have disconnected the battery all of the windows want re-setting and I notice that as we go through the relay-clicking sequence the power to the windows is turned on & off too (but I would expect that if there was a "reset" signal being sent or generated from somewhere).
I have no idea what is going on.
 
Thanks Mark,
No sign of leaks or damp. Checked with super-sensitive fingers and a moisture-meter.
I'm going to change out the battery next. Maybe it just doesn't have the guts to keep the BECM happy & content.
I know the whole system throws up phantom faults if your battery is knackered (had that before).
 
while the battery is of pull the becm plugs one by one and give them a spray of contact cleaner and a wiggle around, just because you can't feel damp it may have been at some point,.
 
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