ABS pump current draw

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ronsealdeath

ronsealdeath

Sagging Member
Posts
1,851
Location
Swansea, Wales
Hi anyone know how much current an abs pump should draw? Mines quite loud and seems to cause my starter to slow crank even with a fully charged battery. I assume its the abs pump as when I crank it over and the pump doesnt operate ( accumulator full I guess) then she spins much faster! Battery is 70ah brand new holds 12.63v overnight.
Thanks in advance
 
Could anyone help with sourcing a cheap DC clamp ammeter so I can try and measure it? I am struggling to find one that does DC for less than £50 and that's too rich for me!

I'm guessing the pump draws a fair bit as it has a 60amp fuse? so my 10amp multimeter would probably blow its own fuse put in the circuit.

Cheers in advance
 
ronsealdeath said:
Could anyone help with sourcing a cheap DC clamp ammeter so I can try and measure it? I am struggling to find one that does DC for less than £50 and that's too rich for me!

I'm guessing the pump draws a fair bit as it has a 60amp fuse? so my 10amp multimeter would probably blow its own fuse put in the circuit.

Cheers in advance
Click to expand...
www.CPC.co.uk do low cost clamp meters, they work fine, I have one.
 
Cheers Datatek I'll have a look there.

SaintV8 I think the fuse handles the hydraulic pump relay only and on checking its 30amp. So that does't tell us how much current the pump draws but I am guessing a fair bit based on the fact it seems to affect the cranking speed so much.

I'll try with an ammeter and see what I get but I have no reference for what is normal. I can't even find anything for other wabco ABS pumps! Very little out there.

It would be good to hear any other experiences of ABS pump operation and whether mine is on its way out (loud and maybe drawing too much current?) Who knows.

One question I have struggled to find an answer to is whether a P38 ABS pump with the accumulator, would fit and work on an RRC? Seems like there is only an in and an out, so that would work. Anyone know if the plug for the loom is similar/ the same? Be good to know if it needs replacing.

Cheers muchly
 
ronsealdeath said:
Cheers Datatek I'll have a look there.

SaintV8 I think the fuse handles the hydraulic pump relay only and on checking its 30amp. So that does't tell us how much current the pump draws but I am guessing a fair bit based on the fact it seems to affect the cranking speed so much.

I'll try with an ammeter and see what I get but I have no reference for what is normal. I can't even find anything for other wabco ABS pumps! Very little out there.

It would be good to hear any other experiences of ABS pump operation and whether mine is on its way out (loud and maybe drawing too much current?) Who knows.

One question I have struggled to find an answer to is whether a P38 ABS pump with the accumulator, would fit and work on an RRC? Seems like there is only an in and an out, so that would work. Anyone know if the plug for the loom is similar/ the same? Be good to know if it needs replacing.

Cheers muchly
Click to expand...
A 30A fuse would be used to protect a circuit carrying 22A or thereabouts....(based on the 135% rule)

I would imagine the pump running at 20A is perfectly feasible...which on a 70AH battery is a substantial amount and will no doubt affect the CCA of the battery...
 
Do a voltage drop test on your engine earth. Here's how with a digimeter place one lead -dc securely on the engine casing and the red lead onto the battery earth. Now with the engine cranking the volts should not exceed .5VDC 1/2 a volt. "What doesn't go through the earth goes through the meter". If your volts are over then carefully check the terminals for corrosion and also check the earth leads bolts as it may look good, but I have seen so many with a bad cable or placing of the earth. Ideally the best place for the battery earth would be at the starters mounting bolts, as this is the place where the maximum currant goes. Remember you are doing a voltage drop test and not anything to do with amps. the currant a starter draws is very high, well over the 10amps most meters now have.
 
tnseal said:
Do a voltage drop test on your engine earth. Here's how with a digimeter place one lead -dc securely on the engine casing and the red lead onto the battery earth. Now with the engine cranking the volts should not exceed .5VDC 1/2 a volt. "What doesn't go through the earth goes through the meter". If your volts are over then carefully check the terminals for corrosion and also check the earth leads bolts as it may look good, but I have seen so many with a bad cable or placing of the earth. Ideally the best place for the battery earth would be at the starters mounting bolts, as this is the place where the maximum currant goes. Remember you are doing a voltage drop test and not anything to do with amps. the currant a starter draws is very high, well over the 10amps most meters now have.
Click to expand...
He is after the Amps the ABS Pump draws as his cranking speed is greatly reduced while the ABS pump is in operation...
 
Thanks all, I guess I just cram one of them massive batteries in that datatek suggested in another thread.

Or as I have a spare battery tray on the n/s and a good spare battery to put in, I may just wire them in parallel on a switch to give a jump when required. Cheap backup!

Cheers
 
Thanks wammers the starter is recent and battery new, I know this doesnt guarantee they are tip top so ill add it to the list to check the starter out.... if it ever stops raining
 
ronsealdeath said:
Thanks wammers the starter is recent and battery new, I know this doesnt guarantee they are tip top so ill add it to the list to check the starter out.... if it ever stops raining
Click to expand...

Should be ok then, but bad earth points and connections can cause problems.
 
wammers said:
Should be ok then, but bad earth points and connections can cause problems.
Click to expand...

Cool, ill get under and check that out. Design seems poor for earth points; the earth for the abs pump etc goes to an unsleeved section of the main battery earth. This is quite green with oxidation. I have spare battery cable here so will replace the run to the starter.
Cheers for the suggestions all
 
Just to finish this thread off, I got my ammeter and measured current draw on the ABS pump. Its an analogue meter but I'm reckoning between 10 and 15 amps draw on the pump, so minimal.

Starter motor next culprit, will test the draw this week when I get a chance. Have a spare to put on which I am 95% sure will cure the problem.
Cheers all
 
lol

dodgy earth (or power +ve to starter)..fecked starter is my bet..

ie my cranking speed dont alter if i have all lights on..(inc 200w spots..electric power steering.(40amps on load) heated window .heated seats...etc..
but i got a proper varta battery..

anyway...car is designed to start with abs pump on..
 
zen said:
lol

dodgy earth (or power +ve to starter)..fecked starter is my bet..

ie my cranking speed dont alter if i have all lights on..(inc 200w spots..electric power steering.(40amps on load) heated window .heated seats...etc..
but i got a proper varta battery..

anyway...car is designed to start with abs pump on..
Click to expand...

Yeah I was totally off the mark there, new starter going on tomorrow evening so will see how it goes
 
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