That’s why your ac clutch isn’t engaging at idle. The ac amplifier isn’t seeing a high enough engine rpm to allow for compressor clutch engagement. I wonder if there is a way to bypass that.

For testing, can't he just apply 12volt to the magnetic clutch compressor and monitor the ac clutch feed wire with a mult meter to see if it's kick on and off propetly?

See if it the clutch compressor working properly.

I just tape the wire jumpers in place and monitor all from in cab powering the ac clutch off our cigarette lighter adapter plug.

If the meter is going 12volt then when it clicks goes out when the ac relay kicks on and off. The ac amplifier is working properly.

If it's not sending voltage yo the mag clutch the issue would be in the sc circuitry.

If nothing else these jumpers would eliminate components as good or bad if nothing else?

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Since the compressor clutch engages at higher rpms then that part of the circuit is intact and not the issue. The problem is the ac amplifier not telling the compressor clutch to engage at idle which would be due to low engine rpm. Since it engages at higher engine rpm's I would think that the signal from the ecm is fine. I think the most likely culprit is the ac amplifier not telling the ecm to idle up for the clutch to engage. Either the ac amplifier is at fault (not likely since it was replaced with OEM) or the circuit between the ecm and ac amplifier for that signal/request is the problem.

Man I hope it's not his ac amplifier again.. My ac issues are mostly rotted out Condensers. Warn out compressors.

I was theorizing that the gap in the clutch is just big enough. That at low rpm it engages and slips and at higher rpm it latches and doesn't slip. However, your not getting the correct rpm signal or the ampflier not sending the engage signal at low rpm.

Maybe the densos magnetic clutches are all or nothing as I can't say I even had a magnetic ac clutch fail on a Toyota.

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So let's start from the beginning I guess?

What is the confirmed engine idle after warm up?

No voltage at idle, zero, zip, nada….😡

It’s within spec 7-750

@badluck is on the correct path. It's in ac circuitry. His theory are extremely solid. He explains it on my question post on how to test it with wire jumpers from your cab.

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I just have to know where to look, and what to test.

I have a 2000 EWD which would be close, but you really need to find a 99 EWD to reference for circuit testing.

I'll see what I can dig up tonight when I get home, if I forget to post anything by like Saturday just ping me in the thread; this week has been a bit chaotic so I've been known to get distracted.

Is 5 volts normal measuring from the back side of the connector on the amplifier while it’s connected?

My manual says positive battery voltage. Doesn’t specify an amount

Battery voltage is what the voltage is at the terminal is. So 12.4 to 12.8 would be a example of battery voltage.

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Well then, that’s not good.

I’m trying to get another amplifier to try.

I went through the diag for the ac. Pin 3 to ground with clutch engaged was 5v