Frozen E

First off, this is for an EM1.
Having some electrical issues.

First off, the radiator fan:
Engine comes up to operating temp, needle hits the half way point on the temp dial and the fan never comes on. Needle continues to climb, still no fan. Eventually I just jump the 1&2 (or is it 3&4?) terminals in the fuse box after pulling the relay and the fan comes on. I actually got to the point where I wired up a toggle switch and ran it inside the car so I can control the fan to make the car drivable.

Sort of the same thing for the AC compressor. Pressure switch is good. System has a good charge on it. If I hit the AC button, the condenser fan comes on but the clutch doesn't engage.

If I jump the 1&2 (or 3&4) terminals the clutch energizes and I get my icy cold air. I COULD do another toggle switch for the compressor too, but that would be bypassing all the safeties and temperature controls inside the car. Don't really want to do that.

So what gives? Did I miss a ground wire or something somewhere?

99.999% sure I didn't miss any blown fuses, since everything comes on if I manually jump out the relay. So power IS there.

Former User

Plug the connector back into the fan switch, and then bleed the cooling system (may take 20-30 minutes):

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push/turn the dash heater lever/**** to MAX heat. Fan need not be on.

3) Follow the directions in the diagram below




If that doesn't help, then replace the fan switch.


Sounds like a bad compressor clutch relay. Swap the condenser fan relay and the compressor clutch relay. Does the clutch now engage when the A/C button is pushed but the condenser fan does not run?

Frozen E

Cooling system was bled properly. Done thermostats plenty of times and haven't had an issue with spikes, gurgling, or any of the other tell tale signs of air bubbles.

As far as the clutch relay, I've swapped it out with every other relay in the under hood fuse/relay box and it still does the same thing. I'm kind of stumped.

Thank for checking in though. If you have any other ideas, let me know please.

motegicivic

Does the temp climb while driving? or idling or both?

Have you jumped the thermo switch directly? if so does the fan come on?

As for the AC I am wondering if it is a control panel problem.

Former User

Have you replaced the fan switch?

Does the clutch engage if you unplug the pressure switch and then ground the Blu/Red wire terminal in the connector?

Former User

If the control panel were the problem, pressing the A/C button would not turn on the condenser fan.

Frozen E

So here's where we sit as of tonight.

I pulled all the relays out and plugged each into the condenser fan socket which I know for a fact is good, and they all turn on the condenser fan. So all relays are known to be good.

Jumping the connector for the fan switch does nothing. First thing I tried to do. Sorry I didn't mention that earlier. I also ohmed out the switch itself with the engine cool and then when it was up to temp. It actually DOES open and close. So that's good.

Also tried jumping out the connector that goes to the high pressure switch that screws into the receiver/drier and that didn't kick the clutch in either.

Both things are weird to me, which leads me to believe that there might be something fishy going on with the ECU or a disconnected ground wire somewhere, or something.

I just don't want to fork out $99.50/hour at Honda for them to go digging around checking stuff I already know to be good.

Former User

If you wire the radiator fan directly to the battery (power and ground), does the fan run?

Again, do this:

Frozen E

Oh, and with the AC, it worked for a day when I put all the AC components back in, had the system in a vacuum and recharged. Granted, when I first broke the vacuum with a can of refrigerant the clutch didn't kick in at first. I actually had to turn the ignition off and back on for it to come on. Which was kind of weird to me. But ever since the day after that, the AC had been down.

Pretty shitty situation because I've actually been doing HVAC on residential and commercial equipment for about 15 years. That's why this is bugging the crap out of me.

Frozen E

Radiator fan is good. So is the clutch. Because I can power both using a toggle switch wired in like the attached picture.

Frozen E

The above picture tells me 100% that power is there and fuses are good, it's just not getting to the coil side of the relays. I'm just REALLY not looking forward to having to poke around on the back of those damn ECU connectors.

Frozen E

Anybody have a pinout diagram of the EM1's ECU connectors? With labels preferably.

Former User

Again, do this:

Frozen E

Post #7, 3rd line from the bottom. Yep, I jumped the pressure switch and got nothing.

::EDIT::
wait, you want me to GROUND that out, or jump the connector?

Former User

Correct. GROUND. It's a different test.

If the clutch does not engage by grounding the Blu/Red wire terminal, then measure voltage to body ground at the Blu/Red wire terminal. What is the voltage reading?

Next unplug ECU connector A and then ground the Blk/Red wire terminal (A17) in the connector. Then turn the key to ON(II). Does this cause the clutch to engage? If not measure voltage at A17 in the connector. What is the voltage?

Former User

Radiator fan -- have you voltage tested installed hood fuse 57. If you jump the radiator fan relay from the fuse 17 or 57 terminal to the fan terminal, does the fan run?

Frozen E

There's 4.6VDC on that wire. Feeling kind of iffy about grounding out a full 5 volts, especially if it's coming from the ECU.

Former User

When you press the A/C button, this voltage is grounded at the heater control panel.

Turn the engine on and briefly ground the Blu/Red wire terminal. Does the clutch engage?

Frozen E

Ok, grounded out the black/red wire and nothing. Idle speed increased a few hundred and then sort of came down, but that's about it. Same thing happens when I jump across the connector.

As far as the fuse thing goes, which one's 57? 17 is under the dash, right? Those supply the actual power to the motors themselves. All fuses under the hood are good. Pulled them all and ohmed them. Well, the mini fuses. Didn't touch the 40s and 30s for the power windows, defroster, heater motor, head light, the 10A hazard and 15A horn fuse.

The 15A FI E/M, 7.5A Back up (Radio), 20A DR Lock Unit.Roof, 20A Condenser fan, and 20A Cooling fan fuses all check good with voltage going across them all.

Former User

Do you mean Blu/Red wire?

Ohm testing tells you that the fuse is good. It does not tell you whether the fuse gets voltage. Test for voltage on both top test tabs of installed 20A hood fuse 57.

Former User

Now do these tests:

Frozen E

Voltage is there on all of them. With the engine off and while running.

And yeah, it's the blue/red.

I've got the actual HELMS manual sitting in my lap in front of me, and the circuit for the radiator fan is so damn simple, it's not even funny. Where's the one for the AC?

Former User

We'll return to the radiator fan problem after you do the tests in post #21. You are getting close to pinpointing the A/C problem.

Frozen E

Ok, pulled the A connector. Measured A17 on the plug to ground and got nothing. Grounded it out, nothing.

Checked A17 on the ECU and got nothing. Didn't bother grounding that.

I had to unbolt the ECU to do this, but ran a jumper cable from the negative battery post tp the ECU chassis just to make sure it was grounded and wouldn't get messed up readings.

Frozen E

Scratch what I said, I used a smaller tip for my meter and hit the connector from the back. There's battery voltage there, and grounding it out DOES pull in the clutch.