Hey all,
I have an '07 RDX with the technology package that is having a cold start issue. It's been going on about 3 years total but only when winter hits and the temperatures get to be about 30°F or below. The car cranks, but too slow to start. Immediately after I put another source of power on the battery it will fire right up. My local Acura shop has checked it out and they said it would be good to go, they disconnected the hands free unit. I have replaced the battery a total of 4 times, I had the starter rebuilt and replaced the terminals for the battery. I have checked over the last couple years and it has not been losing voltage when it was not running. Any information would be appreciated greatly.

 

What about the balance of the starter wiring and main battery ground? I haven't looked at the RDX cabling but the Honda K-series units had a section of bare-wire ground line that's known to rot with age.

If you have a meter you can compare the during-start voltage at the battery to the same at the starter; if there's a significant difference it could be your problem is wiring-related.

 

Welcome to the board!

Something must be up, have an 08 base with no starting difference between summer and winter at -35C windchill, Toronto/Canada area. Battery is a nominal 500 and did change two batteries in 3 years, most likely the batteries as they tested bad.
I did disconnect the HFL module, the giveaway was it was hard to start after not driving for at least 48hrs, no matter the season.

ELECTRICAL
The cable to the starter should be easy to check for unusual electrical resistance. There was a report of hidden corrosion within the cable itself, do a search of the 1st gen folders.

Do the same for the grounding loops. There are several grounding wires in the engine bay, relevant in your case:
one connects engine to the car frame on the passenger side, through the engine mount, (in the corner with the windshield reservoir).
One connects the battery to the frame, follow the cable.

Check the charging voltage, use an OBD2 device and a phone app to do that from inside the car while cruising, got a 14.3V when checked idling.

Thanks to dmodels:
How to buy a new battery
https://acurazine.com/forums/1g-rdx-...attery-890429/

How to maintain one
https://acurazine.com/forums/1g-rdx-...attery-775689/

Fuel delivery
Turn the key to on without starting the car, for 30 seconds (powers the fuel pump to proper pressure first)
Take the key out, reinsert and start the car. Any difference?

Mechanical
For this winter I switched the oil to pennzoil platinum 0w20, they added the HTO-06 specification, past couple of winters had PP 5w30, ymmv

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