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Discussion Starter · #1 ·
Hello,

An issue ive noticed with my P38 is every couple of seconds there is a strange buzz sound and all the lights dim very slightly including the ones in the cabin and the headlights then come back to full power this continues to happen all the time while driving the car its barely noticeable but, I wanted to know what might be the cause for this.
 

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1995-2002 Range Rover P38A
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clean all the earth points in the engine bay,if you can make up a new earth lead from the battery to the chassis then to the engine. also check the engine bay fuse box for signs of burning.
 

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Worth checking the power cables from battery to starter and to alternator and to fuse box as well. I've just replaced the ones on my '95 and the starter motor now spins like a turbine and, interestingly, a lot of electrical glitches that I'd learned to love disappeared. Interestingly the tests in the sticky on the old system all checked out OK.
Just for fun I stripped the old cable joints and terminals for a looksee and the corrosion was impressive
 

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+1 on actually removing all of the cable ends, cleaning well, and re tightening.
In most cases the electrical sticky will point to an issue, however, as OB points out, not always.
It is also not a bad idea to have the battery checked, as an weak battery will play hob with an P-38.
The buzzing sound ~could~ be the ABS pump cycling, which could indicate a dodgy accumulator.
 

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+1 on actually removing all of the cable ends, cleaning well, and re tightening.
In most cases the electrical sticky will point to an issue, however, as OB points out, not always.
It is also not a bad idea to have the battery checked, as an weak battery will play hob with an P-38.
The buzzing sound ~could~ be the ABS pump cycling, which could indicate a dodgy accumulator.
I'm OB Bolt?
Good to see your support here though. Hope sun's shining in NZ :)
 

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Discussion Starter · #6 ·
Well, I have a brand new battery in there so I'll have to rule out that it's a bad battery. I have noticed something when I touch the brakes I hear the buzz and the lights dim including the ones in the cabin. Every single time I press down the brakes you hear a buzz then everything dims so I think it may indicate something. However, even if I do not touch the brakes at all even when the car is idling I will hear the buzz and everything will dim and come back to normal every couple of seconds.
 

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Yep, OB, you are Orangebean.......
As for the buzz, you need a new accumulator on the brake system.
It is the black sphere on the ABS pump. It is VERY easy to change once you have pumped the brakes about 20 times with the key turned off to deplete any possible pressure.
You still have a cabling issue as well.
For that matter, NEW battery does not always equal GOOD battery.
Do yourself a favor, and have it tested.
Then, do all the cables......
Oh, and yep! nice early Summer Wx up here in Bay of Isles.:dance:
 

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+1 on Bolt's suggestions. It sounds like you have a poor connection somewhere so that every time the ABS pump kicks in (more often than it should due to the dying accumulator) the power being drawn causes a voltage drop so the lights dim. You can check easily enough by putting a meter across somewhere convenient (like the cigarette lighter socket) and watching what the voltage does when the pump runs. Check at the battery itself and if it still drops, then the battery is not as good as you think. You'll probably find that the same happens if you turn something else that draws lots of current (like the heated windscreen or the heater blowers) on.
 

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Discussion Starter · #9 ·
Just an update the buzz from the accumlator was getting louder and stranger I came to reverse out of the parking lot and guess what no brakes at all. The lights dimming seemed to completely have stopped and there was no more sound coming from the accumlator. I took my car to the RR mechanic and he told me my brake pump is completely dead due to a faulty accumlator. Guess I'll have to change that out completely but yea, the lights dimming problem has stopped which means it is related to the brake pump or its connection.
 

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An accumulator make no noise at all. It only stores brake fluid under pressure. When an accumulator fails the pump runs more frequently until it finally burns out. The bearings seizing or motor winding burning out would have caused additional draw creating the dimming lights. When the pump failed it most likely either finally blew the fuse or killed the relay so there i no longer any draw. It is very odd you make no mention of any warning lights on the dash...
 

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Yea, I was wondering about the Three amigos as well.
PO Probably removed them, or as they had been on continuously, they all burnt out.

+1 on the cause of death as well as the cause of the dimming.
As always with P-38s, if you ignore the signs, the fix becomes a LOT more expensive
 

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errr, uhm... three amigos is not a code. it is not something you can turn on and off. Each of the "three amigos"/three warning lights involved have their own triggers and meanings.

Please use the search function for more information so we can stay on topic with the OP.
 

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Discussion Starter · #14 ·
I actually did have the three amigos come on but, after switching off my car and back on they went away I don't know why anyways I have ordered another brake pump so I'll replace the whole part with the accumlator pressure switch included let's hope this fixes the problem once and for all.
 
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