What have you done to your P5 today?

Today, wheel studs and an oil change since there was no record of the last one being done. The passenger side brake was missing the bottom slide pin :eek:... Had to drive 45 minutes away to get ahold of one. The studs were rather easy to get knocked out and not too bad to get them to pull in with just a lug nut and the brake rotor.
 

i12drivemyMP5

___ 323F ___
Contributor
The hell with stupid bulb clips for the h1 hids in the retrofit projector setup. Found the real solution from morimoto.......

59EB5275-D8FE-4727-B949-A9FF9E2E9EC3.jpeg
 

BenjiHoggi

OEM+
:
Oregon, USA
:
22v Protege5
Alas I am plagued by the common AC fan speed issue - no AC on anything but speed 1, not even a flicker. I've tried the resistor fix twice, with little success.

Another enthusiast recently pointed me toward this cool adapter, which supposedly fixes this problem. Anybody on here order one of them, or have any experience to speak of? Just wondering if this will work any better than my resistor hack. I'm no stranger to wiring, and don't want to spend money if it's a simple problem I can fix myself.

I've done lots of searching and reading on here, but haven't seen many other fixes worth trying. Feel free to throw them at me if I've missed them.
 
issues I need to address are...a couple of CEL codes.
Brought forward from your original list of things to do.

FWIW, these are like $18 from Amazon and install in a few minutes. If this doesn't clear the CEL, then you might also need to get a Charcoal Purge Valve (it's under the rear bumper).

This purge valve cleared my P0455 CEL-> https://www.amazon.com/dp/ (commissions earned)
Right now $11.99 with Prime Member 2 Day shipping.

It goes on the top of the air tube before the throttle body (photo attached below).
PCB had to lead me to it like a horse to water as the original valve was configured differently.
 

Attachments

  • P5 - Purge Valve - CEL P0455.jpg
    P5 - Purge Valve - CEL P0455.jpg
    118 KB · Views: 67
Alas I am plagued by the common AC fan speed issue - no AC on anything but speed 1, not even a flicker. I've tried the resistor fix twice, with little success.

Another enthusiast recently pointed me toward this cool adapter, which supposedly fixes this problem. Anybody on here order one of them, or have any experience to speak of? Just wondering if this will work any better than my resistor hack. I'm no stranger to wiring, and don't want to spend money if it's a simple problem I can fix myself.

I've done lots of searching and reading on here, but haven't seen many other fixes worth trying. Feel free to throw them at me if I've missed them.
No experience with that AC fan speed adapter (or the headlight adapter).
What is your resistor hack?
 

pcb

The Diagram Dude
:
2002 MP5
Alas I am plagued by the common AC fan speed issue - no AC on anything but speed 1, not even a flicker. I've tried the resistor fix twice, with little success...

Do what I did and install four relays in line with your fan switch...

I reduced the current though my switch from +12 amps down to 20 milliamps to run the relays.

The resistor trick just dumbs down the sensor circuit.

You are still cooking your fan switch.


Post in thread 'Permanently fix the "no A/C on fan speed 2/3" problem' Guide - Permanently fix the "no A/C on fan speed 2/3" problem


My relay pack has been working fine for close to ten years.

I can send you the schematics if you're interested...
(I need to find them though,..
They're on this forum somewhere. Lol)
 

pcb

The Diagram Dude
:
2002 MP5
This is what my four relays look like, and kind of how they are wired.
My fan switch was sorta burnt, but it was good enough to handle the 20 milliamps for the relays.

I might be able to find some better pictures.

A new fan switch should help your problem.
They had a revised, beefier fan switch for late model P5's. 2003.5 models.

20210811_042101.jpg


20210811_042141.jpg



I've got some more drawings somewhere, but photobucket may have stolen them...


Here's another diagram of what I did...


Screenshot_20210811-044859_Samsung Internet.jpg



You basically cut the 5 wires of the fan switch connector and put the relays in between.


Some people have had their resistor pack burn out, or the wiring to it, but a burned out fan switch/connector is way more common.

I used 30 amp relays ($10 each) and there is no voltage drop across them.

A 1.1 Volt drop across the fan switch will kick out your AC on fan speeds 2 and 3.
 
Last edited:

BenjiHoggi

OEM+
:
Oregon, USA
:
22v Protege5
This is what my four relays look like, and kind of how they are wired.
My fan switch was sorta burnt, but it was good enough to handle the 20 milliamps for the relays.

I might be able to find some better pictures.

A new fan switch should help your problem.
They had a revised, beefier fan switch for late model P5's. 2003.5 models.

View attachment 301964

View attachment 301965


I've got some more drawings somewhere, but photobucket may have stolen them...


Here's another diagram of what I did...


View attachment 301968


You basically cut the 5 wires of the fan switch connector and put the relays in between.


Some people have had their resistor pack burn out, or the wiring to it, but a burned out fan switch/connector is way more common.

I used 30 amp relays ($10 each) and there is no voltage drop across them.

A 1.1 Volt drop across the fan switch will kick out your AC on fan speeds 2 and 3.
Haha...normally I'd complain that that isn't OEM+ enough, but the temps these days are making me reconsider. Going to be 104F today and I'm wishing I had just about anything better than my current setup.

I should check if my AC wiring is toasty. If I understand what you're saying, the current of the AC system is what causes things to degrade in that regard, and that's something I could investigate and potentially fix.
 

pcb

The Diagram Dude
:
2002 MP5
I should check if my AC wiring is toasty. If I understand what you're saying, the current of the AC system is what causes things to degrade in that regard, and that's something I could investigate and potentially fix.

I'm willing to bet that a new blower motor switch will fix your problem.

20210811_141911.jpg


You can remove the individual connection tabs from the plastic connector and solder them directly to the back of the fan switch.
20210811_140610.jpg
20210811_140636.jpg

Screenshot_20210811-143937_Samsung Internet.jpg



I had success with cleaning up the connector on the fan switch and replacing the terminal ends. I took apart my fan switch and cleaned it up.

It worked for a while but then my AC light started flashing so I installed the relays.


The problem with the fan switch is that it can't handle the +12 amps that run through it.

There is a tiny copper contact surface that rotates to the different fan speeds.

That contact point ends up getting dirty and carbonized and developes some resistance.
Then it starts getting hot and the heat travels out of the switch and into the connector and wires and everything starts melting and gets burnt.

The sense circuit is only for the AC and once your fan switch has enough resistance and gets that 1.1 V voltage drop across it, the AC kicks out.

The blower will still blow with no AC until the switch and wires are completely burnt and no longer conduct electricity.
 

pcb

The Diagram Dude
:
2002 MP5
Haha...normally I'd complain that that isn't OEM+ enough, but the temps these days are making me reconsider. Going to be 104F today and I'm wishing I had just about anything better than my current setup.

Our OEM switch is a piece of crap. Lol

There was a service bulletin put out about it and if you were lucky enough to have your switch crap out while it was still under warranty, they would fix it for free.


20210811_145044.jpg




If you have the resistor fix installed as well as a new fan switch, you should be good to go.

That adapter could help too.
It's all about having a really good connection with very low resistance so that your sense circuit doesn't activate.


I just read that service bulletin, and they did exactly what CheeseHelmut did with his resistor fix.

They replaced the circuit board with a new one that changed the sense voltage from 1 volt to 2 volts.

That replacement circuit board was probably the entire control unit that would have come with a new fan switch.

I'm pretty sure that they beefed up the fan switch too.
 
Last edited:

pcb

The Diagram Dude
:
2002 MP5
If you have the resistor fix installed as well as a new fan switch, you should be good to go.

That adapter could help too.
It's all about having a really good connection with very low resistance so that your sense circuit doesn't activate.


This is the inspection for the resistor pack for the blower motor.


20210812_100235.jpg



On fan speed 4, the resistor pack is bypassed and the 12 volts goes directly to the blower motor.

On fan speed 3, the power goes through the 0.18 ohm resistor to reduce the voltage and current to slow down the blower.
Then 0.54 ohms (2 resistors) for fan speed 2, then 2.5 ohms (3 resistors) for fan speed 1.

That resistor pack gets hot, so they have to put it in the airflow of the blower motor to cool it down.

Fan speed 3 has only 0.18 ohms of resistance but generates huge amounts of heat.

It's quite easy to get less than 1/4 ohm of resistance in the blower motor switch, and the connector, and the wire itself, generating huge amounts of heat that could even be a fire hazard.

Once things start getting hot and burnt up a bit, the resistance climbs even higher and generates even more heat.



So it's not just a matter of keeping your sense circuit from activating, it's also a matter of burning up your switch and wiring in the winter, when your heat and defrost are turned on.

That's why I installed relays in line with my fan switch.

I have very low resistance, so very low heat and no activation of my sense circuit.



The same sort of thing was happening in the 70's and 80's with headlight switches.

All the power for the headlight bulbs was going through the headlight switch in the cab and starting fires.
They ended up using relays to remove the power from the switch and now it is standard practice for safety reasons.

My 94 Tracker had the headlight relays but the signal switch was still fully powered on the steering column, and smoke started rising from my steering column.

I took apart my signal switch, cleaned up the contacts and regreased it and fixed the problem.

That issue was caused by two 25 Watt signal bulbs. That was enough power to almost start a fire.

Our Protege fan switch really should have been recalled and replaced with relays or a super heavy duty switch.

There is about 145 Watts running through that switch on fan speed 4.
 
Last edited:
:
03 p5, 92 miata
Finally got the retrofits down out of the attic I have had for years and tightened up the projectors to the reflectors. Think I'm gonna luck out and not have to bake them open to stabilize the shaky projectors. Tightened them a good bit and put red loctite on the threads. Also made sure the cutoffs are level.Found new h1 hid bulbs in box with lights. Ordered the spring clips needed to hold them in projector. Have a pr of morimoto 35w ballasts and battery harness from another hid setup on hand. Getting bulbs secure in projectors is only holdup on them going in the car. Have some yellow halogen brights and silverstar parking bulbs out of the current halogen fixtures....can't wait to go back with hid lows in proper housings with correct cutoffs and effective halogen brights as well. Matters since no fogs in msp lip......

View attachment 301744 View attachment 301745 View attachment 301746

Gotta paint those reflectors and really make the retrofit pop!
g--xm7a5HuqSHxCfA_TZE2U338aCEmnFzILlonau4oLH3zLC9LU8aiPloYwRW3OVkYQZMpTT4n-fxF3zIQ_gjP6TWj7dD1UM9OvzhC6jmhNqKkJtBlqe8c8E55BB7cZ5zuemCo38KcEfDkQApJLH-vjsZfZjvYKx2guvJHNbSTYWC6DdQKIZV4EyNXiuWV1RnxTOJ1r6XLU3Lv44lgVXv-axoT4MCCL72eaWuDVoEu9qmE00W9jvb8xOrT6CynHIo67PrlYwKIg1dcNTLAbo04eyYZVoxdFxePtYQ9qTH_pRQ1w4X7OPSGzQ6OrH7P0GVFA1UayciuuoqjEiWNqu6n4iZgjyoAxoUZvvJ-r6ziD1ABe_pyzMgaQbHylsdo8SHrlu1DDX1jEL2qMPU0g3NO8J2UBmIzYiK8ua-mVVTDVnFGyOx01jrIJqbr6akXvZYeuq3PrJKA_fjvRHGan-5gOufWFVAMVkYGHrF75pLzTQrBNnNGWeIcTfkdng9J-sA6ZPE5TdOc7u26MdivNFQRJrglTMJpze6vrZ1mYFFCw6hltxUpso7zBEt1NkIx992FmXIbsch8qK8_a4mHyVizdGmrkPbsSiQlWA4fHf8Hw0SS0Cb58mFkTNmntZ1H0t-aZ03v6UDyDonEmqWBwib6mSal9E2J98R3htUCclSMswy8aVURyF8NPw5BRl4Vh0Y7HHK_mZ-1Onz3NE-09lJBru=w1079-h610-no
 

katapaltes

'03 P5, '17 Miata, stock AF
:
Dallas, TX
:
2003 Protege5
If it doesn't stop pinging, you may need a new knock sensor.

Check the condition of your knock sensor.
They go bad over time and the gell turns to goo and starts running.

It's located right above the oil filter.

(there is a code for it, but it doesn't monitor performance, just the circuit itself.)


View attachment 299102



A new knock sensor may actually fix your pinging without having to use premium gas ?
(but I'm guessing)

The ECU is supposed to adjust ignition timing and such to stop pinging.

The plot thickens... As I mentioned in other posts, 93 octane gas had silenced the pinging my JDM FS-DE engine exhibited while on 87 octane. So I had assumed that the higher-octane gas was the fix for the JDM engine. Well, I just got back from an oil change at the dealer (a free oil change for educators right now, and that includes staff like me) and they said I had a bad knock sensor. So I will replace the knock sensor and retest if I can run 87 octane without its pinging. Then again, I have recently installed an MP3 ECU since testing 87 vs. 93 octane, so that confuses things a bit. But if it doesn't ping with 87 octane and a new knock sensor, I may run 87 or 89 some of the time depending on gas prices.

Also, I have high confidence in the mechanic who works on my car. Look at the pic below and try and figure out why... and then try and figure out which is his and which is mine. :unsure:

He asked if the ECU had helped performance and I couldn't really tell him, so I asked him to go wind it out on the test drive. He said mine certainly has more power than his, but then again, he has over 200k miles while my JDM engine is likely (??) under 100k miles.

1629227879488.png
 

pcb

The Diagram Dude
:
2002 MP5
Well, I just got back from an oil change at the dealer and they said I had a bad knock sensor.

How did they know that you had a bad knock sensor ?
Did you have the code?

20210817_153740.jpg


Then again, I have recently installed an MP3 ECU. But if it doesn't ping with 87 octane and a new knock sensor, I may run 87 or 89 some of the time depending on gas prices.


I'm pretty sure that you'll have to use premium gas with an MP3 ECU.

Maybe just try a 1/4 tank of regular to find out, then you can top it up with premium if it pings.

Pinging can damage your engine.
 

katapaltes

'03 P5, '17 Miata, stock AF
:
Dallas, TX
:
2003 Protege5
How did they know that you had a bad knock sensor ?
Did you have the code?

View attachment 302144




I'm pretty sure that you'll have to use premium gas with an MP3 ECU.

Maybe just try a 1/4 tank of regular to find out, then you can top it up with premium if it pings.

Pinging can damage your engine.

I was wondering the same thing after reviewing your post where you mention that a bad knock sensor should actually throw a code... and I've never, ever had a knock sensor code. How else could they know it's bad, aside from a visual inspection? The service manager did say it was "dripping," or something to that effect. I do know that it's gooey as I checked it the last time I was under the car.

The description on the inspection printout recommends "Replace engine knock sensor due to oil leak." (They may have been dumbing things down a bit for the average customer there...) I know that good knock sensors at Rock Auto cost north of $50, but I was a little surprised to see a price tag of $462 for the dealer to do it as it looks bog simple to replace.

The other recommendation from their multipoint inspection was to fix a leaking left-front axle, and their price to do that seemed quite fair at $276. Note that they can't get their hands on a Mazda OEM axle right now, and would use a third party part so that might be part of the reason that the price seems low.

The mechanic who works on my car (the one who owns the P5) is great. Even if I distrusted the service manager, I'd trust this mechanic, and I always chat with him when I bring the car in for an oil change or for service I can't do, or just can't do at my apartment.
 

BenjiHoggi

OEM+
:
Oregon, USA
:
22v Protege5
I was wondering the same thing after reviewing your post where you mention that a bad knock sensor should actually throw a code... and I've never, ever had a knock sensor code. How else could they know it's bad, aside from a visual inspection? The service manager did say it was "dripping," or something to that effect. I do know that it's gooey as I checked it the last time I was under the car.

The description on the inspection printout recommends "Replace engine knock sensor due to oil leak." (They may have been dumbing things down a bit for the average customer there...) I know that good knock sensors at Rock Auto cost north of $50, but I was a little surprised to see a price tag of $462 for the dealer to do it as it looks bog simple to replace.

The other recommendation from their multipoint inspection was to fix a leaking left-front axle, and their price to do that seemed quite fair at $276. Note that they can't get their hands on a Mazda OEM axle right now, and would use a third party part so that might be part of the reason that the price seems low.

The mechanic who works on my car (the one who owns the P5) is great. Even if I distrusted the service manager, I'd trust this mechanic, and I always chat with him when I bring the car in for an oil change or for service I can't do, or just can't do at my apartment.
My knock sensor is also kind of gooey like yours, and has been for several years. I've never seen a code for it, but my mechanic has told me that it needs to be replaced. I was also shocked buy the cost of a new OEM or even decent quality aftermarket sensor. I'm not exactly sure what pinging sounds like, but If you replace that sensor and your pinging goes away, maybe I should do mine as well.