Any Acura techs or Honda techs?

08 rdx. Stalling issue at idle or rpm’s dropping when coming to a stop at a light or intersection. First of all this is my wife’s car and she has complained about the car turning off on her. I drove it a couple times and I couldn’t get it to do it for me. Well, I decided to drive it all last week and it finally happened to me. On a cold start early in the morning, started the car. It was cold so I turned the heater on. As soon as I turned headlights on, everything on the dash, screen and interior lights flickered and the car wanted to shut off. Raised rpm’s and everything seemed fine for bit. While I was driving, turned defrost on and again everything flickered and engine wanted to shut off. Pulled over and raised rpm’s again and everything was fine until I made it home, except “check charging system” message on dash. Well tested battery and alternator 3 times (three different testers) and all came back good. Also, I have replaced the alternator twice before a while ago. Noticed that with hvac on and compressor cycling the rpm’s fluctuate every time the compressor clutch engages and voltage fluctuates. Also with hvac on is when the vehicle stalls. I was checking fuses last night. Had my multimeter hooked up to the battery while the car was idling. Noticed that I was getting 14.3-14.7v and when the compressor clutch engaged it dropped to 13.8-13.6v. Over some time as the vehicle kept idling and warming up the voltage dropped to 14.1-13.6v and when the clutch engaged to dropped to 12.8v. Now I’m guessing that there is an electrical issue causing an overload. Any insight?



Sorry for the long post. Is possible the ELD (electrical load detector) is malfunctioning? If so where is I located and is it replaceable? Could it be the hands free link module causing an overload issue? Could it be the ac compressor clutch starting to fail? Could it be a bad relay? Could it be the throttle body staring to fail? MAF sensor? Fuel pump issue?



Can anyone provide a wiring diagram of the charging system?

 

It really sounds like a failing alternator. Did you install an aftermarket part last time you replaced it? Which brand?

Those little gizmos that test the alternator are pretty much useless btw.

I'm attaching the wiring diagram but I honestly don't think it will help you here.

 

I get what you saying. I used a battery/alternator tester. Took it to AutoZone and oriellys to have them tested also. The alternators have been replaced with AutoZone alternators.

 

Bingo. Alternator is your culprit.

Aftermarket parts market is terrible these days.

 

I installed a “new “ Duralast alternator on the wife’s 2010 CRV a fews back and recently installed a new Denso on my RDX . Because of the difficulty of installation I’ve always chosen new over the rebuilt ones .

My question : are your replacements rebuilt ?

 

Bad move.. a denso reman is way more reliable than a crappy 'new' duralast.

 

The New Duralast is working as it should .

 

Sounds like a good comparison experiment! Keep us posted on how long each of these last.

How would you rate the difficulty level of the RDX alternator replacement?

 

If you've replaced your belt and tensioner before, the alternator is just a couple bolts past that.

I'd also take out the coolant reservoir and AC condenser fan so you have more room to work.

 

Update I replaced belt tensioner and I installed a OEM Denso alternator. Ran unit for about 15 minutes, drove around town to run errands, so far everything back to normal. Rpm’s do not drop when ac clutch kicks in or when large electrical loads are turned on(headlights, defrost, radio, flashers and high beams). Will continue to monitor and update a week from now.

 

Wonderful news

 

Well the hope only lasted a few days. The issue is back. I even unplugged the hands free link bluetooth (known to cause issues). Still shutting off. Only thing I haven’t changed is the battery (had it tested several times and it tested good every time). Notice that while I was sitting in the car it shut off several times. Turned ac off and it no longer shut off. Could it be the AC compressor? Or something to do with the ac system?

 

Battery. Cells died because the alternator wasn't charging properly.

Edit: turning off AC just reduces the power draw.

 

If you suspect it’s the compressor pull the AC fuse and drive it with other power hungry accessories such as blower motor, electric defroster and headlamps. That should lead to either it’s battery related or compressor related is my opinion .

Very well could be the compressor / clutch ?

 

I have a 2007 and fought your same issue for 2 fricken years! It started out only stalling once every 2-3 months, coming to stops. Not a big deal since it was so infrequent. Then it started to happen weekly, turning a corner, going 70mph on the highway, etc. Stalls for a sec, dash lights come on, but it kept running. Then a few times a day. I chased the battery, alternator, fuses, etc. Its a old car at this point, I thought it could be the ECU?

Someone suggested replacing the battery cables, both pos and neg. fyi, the 9-point positive cable (32111-RWC-A50) is kinda spendy.

Been driving like a brand new car for the 4 months now.