I was thinking about adding an inductor in series with the AC pump in order to slow the current draw and give the alternator/ELD (i'm assuming our Fits have an ELD) a chance to slowly ramp up to the new current draw and thus keep the voltage stable. I think this would definitely be cheaper/easier to install than voltage stabilizers/upgraded wiring. Just wanted to run this past any electrical folks that might be here.

This is still in concept stage as I haven't really thought out the requirements for the inductor (how many amps/henries it would have to be rated for). and where to place the inductor, shielding from moving parts, etc...

 

Never mind, according to Falstad's circuit simulator I would need something along the range of 4.7mH of which the highest current inductor I could find only safely runs 4 amps... Maybe instead make a replacement ELD that delayed the turn on of the ac compressor until the alternator could ramp up to normal output.

 

why does the dimming need to be fixed? its not that bad is it

 

True, its not THAT bad... but it bugs me every time the ac pump kicks in.. which over the lifetime of my fit will drive me bonkers. Right now I'm thinking of setting up an ATTiny chip that will sit between the ELD, ECU and ac pump relay. When the relay would normally get power a pin on the IC would go high. This would cause the IC to disconnect the ELD from the alternator and send the alternator a replacement signal to switch into high output. Meanwhile a timer would start and when it overflows would kick the relay back on, starting the AC pump. After another short time delay 1-2 seconds, the IC would tristate its signal to the alternator and allow the ELD to take back control.

I'm thinking an ATTiny25, a few caps and diodes, a 4MHz crystal and possible a switching transistor for the relay should be able to do the trick. All in all parts cost will likely be less than $10.

 

Even if you could slow down the actuation of the clutch on the AC pump, which I dont think you can as it is probably solenoid based, you would probably wear it out a lot faster. Probably not designed for a soft slip type engagement.

 

I kind of gave up on slowing the ac pump activation. Does the ac pump have a clutch? I figured that since it was electric, it was just a motor that was kicked on and off by a relay. Although I suppose if that's true PWM might be able to slowly activate the AC pump followed by a full on through a relay. That of course assumes the ECU/ELD setup would recognize the average drop in voltage in the system and would have the alternator compensate.

 

The A/C compressor is clutch activated. Belt driven- not an electric motor.

 

Are you kidding me? this is how the car is there is nothing wrong live with it .

 

I dunno I think its pretty cool that he is applying himself to the problem, just think of the people who laughed at Hasport when they decided to do a K-swap.... +rep to the OP for ingenuity

 

just don't use the A/C. roll down your windows. you don't lose power that way too

 

If its belt driven I guess then the only way is to build a more sophisticated ELD that has some preemptive capabilities... although going even that far might not fix the issue if the engine is slowing down during activation.

 

On a related note.
My RX7 TT had a device that when you accelerated it would turn off the AC clutch, as that would zap some power.

That is doable and needed on our fits because we need all the power we can get to accelerate.

Number of ways to do it, find the ecu signal for WOT (wide open throttle) or low vacuum, or add a vacuum switch spliced into a vacuum line and then to a relay.

That IMHO would be a good project.

back to your issue, unfortunately your location of US does not reveal your climate. You may know that in Defrost your AC compressor will cycle on and off. There is a how to thread to eliminate auto AC compressor cycling when in defrost. That could help you with some of your problem.

 

I like your idea for the WOT/AC disable feature and will be looking in to it! on a side note, its cold and very very wet here (updated my locale!) and so having the ac cycle on defrost is definitely a feature I want to preserve, I just want to have my cake and eat it to!

 

well work on the WOT/AC disable, lots of the fit community could dig that.

The defrost deal is NOT an AC comp disable. Make it optional, you lose nothing and have the best of both worlds

With auto defrost AC comp on disable, you have the choice of AC on if you also depress the AC button. The 'how to' just makes it so it isnt mandatory.

Here is the thread, it is really a cool mod
https://www.fitfreak.net/forums/2nd-...c-defrost.html

 

ahh, I thought that would completely disable the ac comp. for completeness heres the DIY for GDs
https://www.fitfreak.net/forums/108654-post101.html

 

I hate that dimming, I wish the fan would just stay on all the time instead of OFF/ON/OFF/ON every 10 seconds. It's super annoying

 

Fairly certain that every Honda for several years has had WOT A/C cutoff.

 

this.

OP, is this your first car? your first interaction with a car? ummm... when you kick on the AC, your lights dim. happens with all cars.

 

even without running A/C the motor idle is strange. The fan turns on, runs 30 second, turns off, back on, back off, all the time. I want to just leave the fan on.

 

the car knows what it wants/doesnt want. it knows whats best for itself