I don't see anything matching in my under hood fuse/relay box however I just noticed a small relay box left of the main box, it has 2 relay sockets and 1x 5 terminal mitsuba relay. Could this be it?

 

I followed the component location reference (Page 22-91 of 03-06 Accord 4-cyl manual) and found refeence to B-Can system and requirement to use HDS to interrogate. You will have to use Mode 1 & 2 manual scheme to check for DTC's.

Have you confirmed absence of ground at Pin 3 of compressor relay?

good luck

 

Regarding Relay Control Module, it is apparently integrated into Underhood Fuse box. See Page 22-132 of 4-cyl Accord manual. This shows tests of module.

good luck

 

I have a v6 model, just to confirm, 2005 EX V6 Coupe, 6 Speed Manual. I'll test the ground again shortly.

 

I know you have V6 model, but V6 shop manual refers to sections of the 4-cyl model as indicated.

good luck

 

My numbering on the original diagram was incorrect with 3 & 4 transposed, here is an updated version.

Based on this diagram
1 - 12v constant
2 - 0v
3 - minimal ohms to ground w/ AC on or off
4 - 12v key on

So the answer to your question is no, i do not have ground on terminal 3

 

Do the copper pins on the relay plug into 1/2 or 3/4?

 

Relay should close if pin 3 is grounded. What do you mean by "minimal ohms"?

Suggest trying a different relay in place of present relay.

If ground signal is not correct, a replacement PCM may be necessary. However, I would want to interrogate the B-can system to see if any codes are set.

If you have a scanner, suggest resetting the PCM. If not try disconnecting negative terminal of battery for 30 secs.

If pins 4-3 or 1-3 were jumped at any time, this could have damaged the grounding transistor on PCM.

good luck

 

Minimal ohms - just a terrible way of putting it. There is a slight change between continuity ground to air vs. ground to terminal 3. Any idea of location of grounding transistor in PCM? pic would be awesome

I believe the pins are 1/2"

 

This likely means the grounding transistor is not open (high resistance). This would explain why AC comp relay won't close.

Grounding transistor is depicted in the wiring schematic. There are no wiring diagrams of the PCM board in shop manual so location is unknown. Replacement is probably not feasible in any case; very small conductor elements, double sided board, and surface mount components. I once tried to repair a PCM (97 Acura 2.5TL) and only succeeded in desoldering some nearby surface mount resistors.

I checked and a replacement PCM was $130-$175 on ebay. You might do better using car-part.com to source a unit. If you do get an exact match for your PCM part no.

However, your symptoms could also mean that PCM sees something that prevents enabling compressor. Suggest checking the two inputs from gauge control module to PCM (A26 & A15, page 21-20). These likely (can't be sure) should show grounded inputs to enable compressor relay. See PCM Pin diagrams in Fuel & Emissions section.

Since compressor was closing (but not cycling) before you jumpered the relay contacts, and not closing at all afterwards, damage to PCM seems possible, perhaps likely.

good luck