044 relay?
03-27-2010, 06:01 PM
#1
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044 relay? what size relay do i need to switch 2 044 pumps?
from what i have found so far each pump is rated at 15 amps, so 30 amps total and i figured id use a 40 amp relay, but i just want to confirm this is right
thanks
from what i have found so far each pump is rated at 15 amps, so 30 amps total and i figured id use a 40 amp relay, but i just want to confirm this is right
thanks
03-27-2010, 08:47 PM
#2
Not really. Look at the relay, most 40A relays are 40A off (terminal 87a) and 30A on (87). A correctly wired relay uses 87, which means normal operating current draw will max out the relay. Also, there is a current surge at power up, so it will draw more than 30A, overloading the relay. Don't try to go cheap on such an inexpensive part. Run one relay per pump, and activate both with the same 12V activation signal (if you truly want to run 2 Bosch 044 pumps at the same time).
03-27-2010, 09:33 PM
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im not trying to be cheap at all! i just didnt realize that there would necessarily be an advntage to running two smaller ones over one large one.
can you go overkill on relays? like would running one rated for 40amps be a bad thing if i only needed a 30amp one?
can you go overkill on relays? like would running one rated for 40amps be a bad thing if i only needed a 30amp one?
03-31-2010, 01:23 PM
#4
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Ive been using a pair of 044's for about 3 years now via a single OE 40A relay.
Ive never had any problems. Although the longest Ive ever driven non stop is about 5 hours. Maybe that isnt long enough for it to heat up
Ive never had any problems. Although the longest Ive ever driven non stop is about 5 hours. Maybe that isnt long enough for it to heat up
03-31-2010, 09:51 PM
#5
stevie, the burst is what hurts. There are contacts in the relay that handle the current. Overtax them long enough, as you are, and they will fail. Design them correctly from the start, and failure is unlikely. Your car, your call.
04-01-2010, 01:19 AM
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No, you cannot go overkill. You might be able to get away with one, but why run the risk? A full relay circuit I use costs about $7, what do you have invested in your engine?
stevie, the burst is what hurts. There are contacts in the relay that handle the current. Overtax them long enough, as you are, and they will fail. Design them correctly from the start, and failure is unlikely. Your car, your call.
stevie, the burst is what hurts. There are contacts in the relay that handle the current. Overtax them long enough, as you are, and they will fail. Design them correctly from the start, and failure is unlikely. Your car, your call.
Well, I cant fast forward time. And if you can explain to me how that relay could cause an engine failure....I'd love to hear it.
Relay works...engine works.
Relay doesnt work...engine stops.
Seems pretty simple to me.
Mine is designed correctly, and Ive had no failures. How easy does it need to be ?
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04-01-2010, 12:07 PM
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I used one 40A relay. Zero problems, and very easy. Just use a quality brand. I actually used an OE relay I took from a car I parted out.
Using a relay for each pump would increase the risk of engine problems should one relay/pump go down.
Using a relay for each pump would increase the risk of engine problems should one relay/pump go down.
04-02-2010, 04:13 PM
#13
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Not really.
It sucks for people using multiple pumps...with multiple controls....more chance of failures.
If one of my pumps fail, I'll know immediately.
If one of yours fail for whatever reason....chances are you wont know until its too late.
I was very reluctant to opt for more than one pump, but at the time, this was the most sensible option. And running 2 in parallel all the time, via one relay IMO is also the safest way of doing it.
If one of mine fails...due to there being no non-return valve...likely my engine will simply cut out due to lack of fuel ( certainly under hard usage anyway, where it matters most ), and fuel pressure will drop enough that its spotted immediately.
With multiple pumps, and non-return valves. Chances are if one fails....you'll just run into a lean condition at the worst possible time.
It sucks for people using multiple pumps...with multiple controls....more chance of failures.
If one of my pumps fail, I'll know immediately.
If one of yours fail for whatever reason....chances are you wont know until its too late.
I was very reluctant to opt for more than one pump, but at the time, this was the most sensible option. And running 2 in parallel all the time, via one relay IMO is also the safest way of doing it.
If one of mine fails...due to there being no non-return valve...likely my engine will simply cut out due to lack of fuel ( certainly under hard usage anyway, where it matters most ), and fuel pressure will drop enough that its spotted immediately.
With multiple pumps, and non-return valves. Chances are if one fails....you'll just run into a lean condition at the worst possible time.
04-19-2010, 03:55 PM
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sorry for all the stupid questions i keep asking about this, but wiring is not necessarily my strong suit... haha
but do i need a 4 or 5 wire?
does anyone just have a link to exactly what i need? that would be alot easier...
but do i need a 4 or 5 wire?
does anyone just have a link to exactly what i need? that would be alot easier...
