I'm new to this forum and want to thank all in advance for any input. So about a week ago I ran a wire to amp, things went smoothly with the install. However when I went to reconnect battery after everything I noticed it had sparked a little more than normal i thought no big deal. Well since the install I don't not have a/c and rad fans don't engage. I've checked my fuses all good. Today I bought new relays for the relay box (3 black ones) put them in still same problem. So I had my car running with those new relays out, took my test light all 3 had their constant power, the one for radiator had a good signal power to it. The other 2 relays that are for the a/c and fans do not have their signal power. My a/c button on my climate control had been goofy since I bought the car, it would stick off or on and I would have to hit max a/c sometimes to trip the ac. So my question is does that ac button give the relays their signal to turn ac on? Or what else ties in between the radio to the relays that I should check?
p.s. wasn't planning on a novel just trying to explain my situation...thanks

 

The ECM/PCM control the A/C condenser fan and radiator fan by sending the ground to the respective relay coils.

• For high coolant temperature situations, the ECM/PCM uses input from the ECT sensor to control the fans. Both fans will run.

• For A/C, the heater control panel grounds the A/C ON input of the ECM/PCM through the multiplex integrated control system and the A/C pressure switch. The ECM/PCM then grounds the A/C compressor clutch relay coil. The ECM/PCM also grounds both the A/C condenser fan and radiator fan relays.

 

thanks for quick response and sorry for all these questions coming. So my finding that the relays weren't getting their signal is due to the ecm/pm not grounding their circuit.? Is the a/c pressure switch the literal button on the radio? I know that my button is bad but my a/c was stuck on. I'm looking at a wiring diagram courtesy of "alldata" and it shows a relay module after the a/c pressure switch then to a gauge assembly and then to the ecm/pcm. Where might I find this relay module, to the left of blower motor? And this gauge assembly it's location?
thanks very much

 

A1: Yes, the ECM/PCM sends a ground signal to energize the relay coils. However, other things have to be initiated before the ECM/PCM sends the ground signal. Refer to my previous posts.

A2: No, the A/C pressure switch is located at the A/C condenser, behind the right side bumper. What you see in ALLdata, is probably the blue wire from the A/C pressure switch going to Audio-HVAC display module; not a button.





A3: The Relay Control Module is built into the under-hood fuse/relay box. This is unlikely to be the cause of your issue.






Instead of replacing parts, you may want to get a service manual and do some tests.

 

Yes, more testing and investigating. Thanks for your time it is much appreciated.

 

So want to apologize for wasting time on this forum. My issue was that I accidentally cut my harness when I ran my new power cord. I patched 5 wires now my car is back to normal. Thanks again.

 

Its never a waste of time when there are concise questions and answers. Other people are following along and may find the answer they are looking for.

Nice job.