THAT SHOULD READ: taaa daa #2 40 AMP FIX FOR P0410 Yippie

Hot dam, its working again

Driving to the inspection station, got a code, dam p0410 secondary air.....

Went home and pulled RCM and found end relay contacts burnt away – evaporated.

Read the posts about it and found that its common, NOW why?

Pulled off relay and asked Tighed to send me relays so I could replace it --- WAIT Iam gonna rebuild the factory relay board, why?

As a Ham (N4MQ), and EE I had to look into this a bit more as someone suggested using a 40 amp relay. Got me thinking, so I powered up my air pump with a 30 amp meter . . BAM the needle was buried on start up, the sucker draws on my car 22 amps+ with the engine off ( lower battery voltage – like 12.5v )

The start up is in the order of 50 amps inrush current with running current in the 30 amp range – alternator running at 13.5 -14.5 volts. I got a soldering gun in 3rd grade ( the first time ha ha ) and have been in electronics for 6 DECADES.
Iam here to tell you the contacts on the factory relays are 5 -8 amps by industry standard. WAY OVER LOADED !!!!!!

Got into my relay boxes and selected a 30/40 amp headlight TYPE relay and saw that it would fit. Unsoldered the old relay and examined it, the contact was all but missing, evaporated from heat. It is quite small maybe 0.08” in diameter, the 40a relay has about 0.125” contacts. The heavy contacts are anchored on very stout bars to support them and allow COOLING OF THE CONTACTS. The relay would JUST fit into the RCM box so I was off to the races as they say.

There are lots of photos in the gallary, please spend some time with them as I tried to make it easy to follow my path. If you attempt this, you need to know how to solder, and unsolder, its important to remove the old relay cleanly. I tried to unsolder the connections and found them tough to clean up with a solder sucker and solder wick. I went to the garage and used a 60 watt iron and my AIR GUN to blow off the solder, and then rocked the old relay out.

To get room I removed the 680 ohm resistor that BRIDGES THE RELAY COIL, it is there as a snubber to prevent spikes – kickback from getting to the driver electronics. It must be reinstalled, I put it on the BOTTOM of the board without putting the leads thru the board - - IMPORTANT dont go into the solder holes and hit the new relay, please.

Physically I had to shorten the pins on the relay, used diagonal wire cutter and strength, could use a dremel or what ever. I only shortened 3 pins to allow the relay to slide toward the back side of the connectors to fit.

What is way cool is that my relay has the open relay contacts pointing to the leads they go to. The frame soldered to the right hand copper support bar for electrical and mechanical support, sweet. The coil leads RED AND BLUE for your convenience go to the board as photographed. There are only 4 connections, 2 coil leads for the 12 relay, and two heavy leads for the contacts, normally open and the common ( frame). The installed relay looks right at home, its open frame, as I discarded the plastic case to allow it to fit.

My contacts are like 400% heavier and better supported, the life span of the new relay should out last me. I have 26,000 miles on my car, which had been my test bed for the super cooler, DCAir intake, Pulley saver, fuel mixture control, and Oil separator designs that I developed for ROB at Needswings.

The relay was an EBAY like purchase for some 4$ and you can pick them up at auto stores or may have some left over from driving light installation kits. My relay has a 30/40 amp rating for closed and open contact points.

The photographs should tell all but Ill do it again to make it is understandable.

Steps as follows.

Pulled RCM and opened case to see burnt relay contact AT END OF BOARD

Unsoldered relay and snubber resistor.

Reinstalled resistor to bottom side of board laying across the hole locations

Matched up relay to photographs and trimmed 3 contacts 1/8”

N/C losed contact 87a cut short, not used
N/O pen contact 87 cut short, I cut at the small hole on the tabs
Coil terminal 85 cut short




Pre soldered 3 leads,
I used Yellow which was bare from board: for pin connection to #87
I used Blue from pin #85: to the copper strip on the board – where its easy
I used Red from board: to connect to coil terminal #86

When relay is mounted I soldered Terminal #30 first, then #87 to bare lead, then the coil leads lastly.

Terminal #30 is heavily soldered to the copper strip on the end of the relay /
board for electrical and support mechanically [ this solder joint and the lead on #87 solidly anchor the relay! ]

checked for solder debris and general goof ups, then replaced into the case, installed and started car, with hood open to confirm air pump is running, felt the case. I started car thru window with door shut to be able to get to the air pump PRONTO.

Air pump runs for less than 1 minute, the tone of the car shifts when pump STOPs like the exhaust note changes after the pump stops.

Grin knowing that the P0410 beast has been slayed. TAAAAA DAAAA.

Enjoy Woody See photos !

PHOTOS https://www.crossfireforum.org/g/album/8091037

 

Pretty Slick!!!

 

Wow , well done.
Thank You !

 

If I send you $30 , will you do mine? (ROTFL). If I tried that , not you or DJ would be able to fix MY board! That's a cure , I just can't do....Awesome!

 

I have not gotten into doing these repairs yet, I suspect that Tighed1 will consider doing this as he has offered standard repairs and he is probably reviewing the notes now. I just retired and have a 440 six pack challenger on the lift getting a new fuel system, a vertical antenna and horizontal loop 160 meter antenna in construction, and home construction I am doing.

Getting repairs on RCMs is important and need speedy attention, and that I can not do now. The hardest part of the change was to remove the old relay by desoldering. Again I did this by using an iron with 60+ watts and an air gun to blow off the solder. DO that and the install is straight forward and easier than doing a plug change.

If I find a better relay, Ill post that too. Enjoy

OH OH OOH, I used white lithum grease spray on the rcm connectors to keep them servicable - dry - shiny, car factories do something like this when they want good integrity.

Woody

 

what if someone could find a better 2ndry air pump that doesn't have the inrush problem?

 

The power needed to move the air takes current and it still is going to draw lots of it. l chose a bigger relay, or you can change relays.

It is a weakness in the cars design and everything is a work around in my mind. Enjoy

Woody

 

With my level of electronic's,I think I'll keep on soldering copper foiled stained glass. I'll call ya when the time comes. Squirrel Crusher

 

In the back of my mind I recall the use of a capacitor to slow down the power surge of motors etc at start up. Would this be correct somehow? We have slow start features on such things these days.

 

In the back of my mind I recall the use of a capacitor to slow down the power surge of motors etc at start up. Would this be correct somehow? We have slow start features on such things these days.
How is it that some have problems and some none at all? Maybe sparking at the brushes in the motor causes sparking at the solenoid.

 

I like it....quick search yielded this...which uses a 1ohm penny sized resistor for a 750W (1hp)
Our application 21.5Ax13.5V only equals 290W.....hmmm sounds too simple. Trick would be in the verification that it works.

l8tr...found these on ebay, but only available in 4 pack.

 

An inductor would retard the rate of rise of current in a circuit. It would store energy in the form of a magnetic field which would give you a large kick back when the circuit is broken. AKA the effect that makes the high voltage of the ignition coil. A capacitor would bridge the contacts and reduce the OPENING arc but would discharge when the contacts close INCREASING the current INRUSH when closing. Physics.

A resistor would reduce the power to the motor and slow or stall it.

There is no free lunch. If you used a big enough transistor you could avoid the arcing if you had enough of a heat sink. No free lunch. One of my patents was to prevent arcing in high current relay contacts, but that is going to cost more money,,,,lunch.

WDY

 

I think I would rather just have the RCM relay power a larger relay located out near the pump...

 

Rather than run another heavy gauge wire out to the pump, wouldn't it be better to just locate the larger relay inside the box with the RCM ? ( only requires cutting and splicing a few wires )

 

Based on James idea why not put the new relay by the battery and use the existing wires or run new wires to the pump?

 

On my c32 the previous owner deleted the whole 2ndary air system. Is there some way I could fool the system via resistor or another trick?

 

anyone have any ideas

 

I bet O2 sensors are involved here. Ww

 

I am only getting the P0410 code as of now. It doesn't hurt performance, just would be nice to pass a state inspection with out having to pay someone. I wonder if jerry can code it out of the ecu??

 

Torque Pro should be able to clear 410, might see how long it takes to come back. Do "pending"s count ?