MAF Power Relay comparison
10-31-2009, 05:46 PM
#1
MAF Power Relay comparison
Hi fellaz. Here I provide a relay that I just bought at Napa. It is a MAF Power Relay and its part number is AR227SB. Now I opened it up and noticed that it is exactly the same as the fuel pump and MAF Burn off Relays. Acording to the first picture, the original MAF Power relay has two small capacitors. Take a look. Now the second picture shows the Napa MAF Power Relay (TAN one is the MAF POWER) along with a MAF Burn off Relay (black). Take a look. Now according to Napa, Theyre relay, MAF Power is correct (although it has no capacitors). But The original GM MAF Power Relay has capacitors. So will It make a difference if I connect the SO CALLED NAPA MAF POWER RELAY?
Last edited by Chevy86 IROC-Z; 10-31-2009 at 05:59 PM.
11-02-2009, 12:21 AM
#3
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Re: MAF Power Relay comparison
Are you sure they're capacitors? In the first pic, it looks like a resistor. I'm by no means an electronics expert, so I'm just guessing here, but if it is a relay, it might be there to lessen the load on the relay coil. I think that would make the relay harder to trip. If it's a capacitor, and it goes across positive and negative, it's probably just there to filter out any RF noise generated when the relay trips on/off.
11-02-2009, 05:14 PM
#4
Re: MAF Power Relay comparison
Ooooppps
. Im so caught up on a distributor capacitor that I wasnt paying attention. Yes, I stand corrected. It is a resistor. The first one is a MAF Power relay (original GM part). Now the other tan one on the second picture is claimed by NAPA to be a MAF Power relay too, but it doesnt contain the resistor. So are the two basically the same? I just dont want to cause my MAF sensor to malfunction. Can anybody help me out here?
. Im so caught up on a distributor capacitor that I wasnt paying attention. Yes, I stand corrected. It is a resistor. The first one is a MAF Power relay (original GM part). Now the other tan one on the second picture is claimed by NAPA to be a MAF Power relay too, but it doesnt contain the resistor. So are the two basically the same? I just dont want to cause my MAF sensor to malfunction. Can anybody help me out here?
11-02-2009, 05:42 PM
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Re: MAF Power Relay comparison
It's hard to tell what terminals the resistor is actually connected to, but it almost looks like it's in parallel with the relay coil. I'm still not 100% sure what it's purpose would be, other than lessening the load on the coil, by allowing some current to bypass it. This should also make the relay harder to trip, maybe so it's less sensitive to power fluctuations or noise? Hopefully someone here has more electronics knowledge than me 
11-02-2009, 05:59 PM
#6
Re: MAF Power Relay comparison
Cool, Thanks Ward
. Does anyone else have any knowledge of the Mass Airflow Sensor Power Relay and its resistors? If so, where do they connect to so that I can solder them. Yup, I know how to solder too.
. Does anyone else have any knowledge of the Mass Airflow Sensor Power Relay and its resistors? If so, where do they connect to so that I can solder them. Yup, I know how to solder too.
11-02-2009, 06:23 PM
#7
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Re: MAF Power Relay comparison
It's hard to tell what terminals the resistor is actually connected to, but it almost looks like it's in parallel with the relay coil. I'm still not 100% sure what it's purpose would be, other than lessening the load on the coil, by allowing some current to bypass it. This should also make the relay harder to trip, maybe so it's less sensitive to power fluctuations or noise? Hopefully someone here has more electronics knowledge than me
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11-02-2009, 07:06 PM
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Re: MAF Power Relay comparison
Ah, that makes sense, I didn't think of that. Could it be because the relay is meant to be on all the time, to keep the coil from getting hot? If so, then i bet that's the difference. The MAF power relay will be on whenever the engine is running, but the burnoff relay only comes on periodically.
11-06-2009, 01:10 PM
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Re: MAF Power Relay comparison
If the resister is in series with the coil it will limit peak current in the coil when energizing and deenergizing. Stopping current spikes "in the coil" both on and off.
If in parallel it will add to the energy needed to power up the coil but remove energy when the coil collapses, preventing power spikes in the circuit feeding the coil from energizing the coils of other relays in the circuit.
Both are types of filters limiting the current flow, one sets a max current and the other a minimum.
Many DC type relays have a diode across (parallel) the coils to stop this voltage spike when the coil colapses.
These current spikes turn into voltage spikes "think welder" and can arc and fuse together the contacts, of the relay contacts controlling the coil or power up other coils in the circuit.
Big relay coils can power up smaller coils when the bigger coils colapse and if the coils are in parallel.
This electrical priciple is well known and used to power the spark plugs of coil type ignitions.
If in parallel it will add to the energy needed to power up the coil but remove energy when the coil collapses, preventing power spikes in the circuit feeding the coil from energizing the coils of other relays in the circuit.
Both are types of filters limiting the current flow, one sets a max current and the other a minimum.
Many DC type relays have a diode across (parallel) the coils to stop this voltage spike when the coil colapses.
These current spikes turn into voltage spikes "think welder" and can arc and fuse together the contacts, of the relay contacts controlling the coil or power up other coils in the circuit.
Big relay coils can power up smaller coils when the bigger coils colapse and if the coils are in parallel.
This electrical priciple is well known and used to power the spark plugs of coil type ignitions.
11-06-2009, 03:38 PM
#11
Re: MAF Power Relay comparison
If the resister is in series with the coil it will limit peak current in the coil when energizing and deenergizing. Stopping current spikes "in the coil" both on and off.
If in parallel it will add to the energy needed to power up the coil but remove energy when the coil collapses, preventing power spikes in the circuit feeding the coil from energizing the coils of other relays in the circuit.
Both are types of filters limiting the current flow, one sets a max current and the other a minimum.
Many DC type relays have a diode across (parallel) the coils to stop this voltage spike when the coil colapses.
These current spikes turn into voltage spikes "think welder" and can arc and fuse together the contacts, of the relay contacts controlling the coil or power up other coils in the circuit.
Big relay coils can power up smaller coils when the bigger coils colapse and if the coils are in parallel.
This electrical priciple is well known and used to power the spark plugs of coil type ignitions.
If in parallel it will add to the energy needed to power up the coil but remove energy when the coil collapses, preventing power spikes in the circuit feeding the coil from energizing the coils of other relays in the circuit.
Both are types of filters limiting the current flow, one sets a max current and the other a minimum.
Many DC type relays have a diode across (parallel) the coils to stop this voltage spike when the coil colapses.
These current spikes turn into voltage spikes "think welder" and can arc and fuse together the contacts, of the relay contacts controlling the coil or power up other coils in the circuit.
Big relay coils can power up smaller coils when the bigger coils colapse and if the coils are in parallel.
This electrical priciple is well known and used to power the spark plugs of coil type ignitions.
By any chance, can you draw where the resistors should go so that I can solder mine? 
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