IMA fan wiring
 

My second question has to do with the fan wiring for grid charging. At the moment, I have a computer fan pulling from the main fan opening. The temperature here isn't going higher than 18F and at night it's in the single digits so I'm not that worried about heat but I would like to get the main fan running. I hear a relay clicking on and off near the fan but there is no power connected to it. So I was wondering if the fan would work properly by adding 12V to the red and black wires. Maybe a diode to block flow backward through the lines and just add the power to the fan.

Does this sound feasible?

Sounds reasonable.

I'm fairly certain that's how the grid-charger works. (Maybe I'll actually confirm that sometime this year if I ever get around to building mine!)

When it's plugged in, one of the power supplies feeds the factory cooling fan via a direct splice.

I'm not sure whether to splice in yet. I read yesterday somewhere that the fan in the Civic Gen1 are smart fans with the control on the fan itself. On the other hand, if the power supplied to the fan at the harness (red and black wires) is simply 12V, and the other 2 wires are part of the sensor that control that relay I hear clicking on and off, then splicing into the power supply and leaving the other 2 wires (yellow and blue) to do their sensing seems at least little logical. If that's true, I would get a working fan that's following orders from the sensors. But... I better study up a little more before I go frying the smart fan's brains.

Did you ever figure this out? I'm about to put together a grid charger for my 2003 HCH and this information would be quite useful!

It would be quite useful but I haven't found out yet. I did read in one article that I was probably dead wrong about the power wires. That article was mentioning those power wires to the fan being the Yellow and Blue ones which really surprised me. It wasn't definitive though so it still would be taking a chance testing it and I havn't. What I did do though was put a strong computer fan on the opening to pull air through and I did notice there was a light pull of air from the inlet for the cooling fan which is on the inside of the back window. I just run it all the time when charging.

There are a lot of differences between the Civic and the Insight and most of the info on this site deals with the Insight. One of them is the reset of the IMA system. After you charge up it's really necessary if you don't want the car charging and discharging when you don't want it too and the assist gets way off the mark sometimes. There have been posts about pulling a fuse under the dash... don't. It does nothing. The fuse you want for the reset is under the hood in the fuse box there. It's a 10A fuse. The box marking says BACKUP and it's fuse #9. If you pull it for 5 seconds, it resets the IMA without reseting the radio/clock. At least that works for me. I put a switch on that fuse so I can just flip it for 5 whenever I charge it. I only seem to need the reset it though every 3 or 4 overnight charges now which seems to me like an indication that the battery is improving.

I hope sombody comes up with a good MIMA system for the Civics. So far it's not been working for Civics I've heard.

Good luck! My grid charger has made the battery run like it did 10 years ago. I only wish I could get the original IMA programming instead of the junk they upgraded it with. It's nasty.

HCH1 Civic Fan wiring & Mima
 

I suggest you look at these threads.

http://ecomodder.com/forum/showthrea...tor-24336.html

Imac&c hch1 civic - Insight Central: Honda Insight Forum

Can the hch1 imac&c prevent battery death? - Insight Central: Honda Insight Forum

HCH1 IPU Fan Control - Insight Central: Honda Insight Forum

I hope that helps.

I will be reading through these posts very carefully! It sound very interesting. Haven't seen much on the gen1 civics so it's good news.

Sounds like one would be able to control the fan using an arduino's PWM pins.

Hmm... Would be nice (and cheap) to be able to make a dumb charger into a smart charger by having it control the fan by PWM based on temperature and the charger by relay based on battery voltage.

I am still in the learning process. So can't suggest a way out.