lazaino

I believe the module is effectively a Solid State Relay driven by a 0-12V PWM signal at 1K hz. It's unlikely that the ECM output has died. Unless you have a scope, actually seeing what's going on is hard. The brushes wore out on my fan motor just out of warranty. A 12V bulb across the fan would give you a good idea if the fan is being driven correctly. Should change brightness with engine temperature and the state of the air conditioner.

Be careful looking at on-line schematics as some of them are wrong.

Ira

gamma-wes

That's what I've found to be true. The dealer where I bought my power steering motor didn't even know it was the wrong one. Seems most people don't even know anything about the SS, especially the dealer. That's why I come on here and ask questions, but I get more snarky comments than answers most of the time. That's how it was on the Mazda forums too, so I shouldn't expect anything less from another forum.

I considered a lighting set-up and I think that I could even pull out my lights from the RC car days to test with. They'd need a couple of resistors to make them work with 12 volts.

I think that I've got a pretty good handle on the issue now though. I was getting little to no voltage at the back of the controller, even with a resistor looped for continuity. It was plenty live before the controller though. Don't know how to test the single controller wire with my multi-meter. I'm sure it's way more complicated than my meter can interpret.

New part is getting delivered today. We'll see.

donbrew

Unless it's a PWM circuit.

Kookie

I had fan problems too. I took the cover off the relay in the fuse box to check it number 1 & to manually actuate it to turn the fan on. (Some times it worked, sometimes it didn't.) It turned out the plug on the car side, one of the connectors, was slightly melted. Fixed the plug to make good connection and it seems to be ok.

My point is that I found that the ECM seems to pull that relay in at 215°. It will release it at around 185°. Also, it pulls that relay when the a/c is turned on.

XtremeSS

Not really sure how you can justify that all forums are full of snarky, unhelpful comments just because it was that way on another forum. This logic makes no sense. You have gotten some very detailed info from the members of this forum yet you have neglected to update your thread with any conclusive results. Care to update your thread so it can be useful to others in the future? Or are you just gonna let this thread become another " new member unconclusive dead-end thread with no results"?

gamma-wes

Yeah, some very detailed info from a handful of members. When I was Admin on other forums, I saw the trend that 4-5 members carried each section while 2-3 trolled each section. It seems to be about the same here, though there aren't as many members. A couple are carrying the responses of each section and a couple are trolling all of the sections. That's just the way that forums work though.

The newest update is that the module lasted about a week and went out again. That means that the fan has been replaced, the module has been replaced twice, the temp sensor has been replaced, the wiring harness was replaced (not only because of the fan but because of the poor condition), and all of the scanning tools I can pay for can't tell me what's wrong (TechII before anyone asks).

ECU is the only remaining issue. Any other input?

Also, before anyone asks; no pins are bent, anywhere. All terminations are made (harness is plugged into everything and there's no dangling/cut wires). Nothing is out of place.

gamma-wes

Talking to the Chevy dealership down the road to hopefully get me out of this stupid car.

This is my first American car in the 14 years of buying cars and I will never own another.

donbrew

So I guess Pulse Width Modulation isn't a good enough hint.
Sorry.

XtremeSS

I'm not sure if this is applicable to the SS fan module due to its absence of a fan relay but, Have you removed the fuse box and checked the harnesses below it? I know from personal experience that it can be difficult to seat the plugs when re-installing. Again, not sure if any related circuits run through it or not. From your description it sounds like the fan is getting the wrong voltages and/or frequency. If it was a ground fault one would assume the fuse would blow if the fuse is the correct size. Shooting from the hip but that's all I got.

gamma-wes

I pulled the fuse box when I put the new harness in it. The relay (micro relay) in the fuse box ties directly into the harness, so I had to pull the box to get the new harness in it.

I retested everything and got the same results only the controller wire is sending zero signal to the module. No voltage, no resistance, no frequency readings, nothing at all. Last time, before the module was replaced, I got 1khz out of that wire.