1KPerDay

Hi, you came highly recommended for people with mystery issues with Acuras.

2004 MDX. 170K miles. I love the car. Don't want to get rid of it.

Lately (past few months) it's been needing a jump start. If anyone runs the battery/leaves on interior light/runs the AC without the engine running (I have teenagers) it's dead. And then even if you don't, some mornings or after work I have to jump it. Thought it must be battery. Go to get new battery. Auto parts guy checks and says battery is good, advises to clean contacts. I do. PITA to reset radio code after disconnecting battery. Whatevrz.

Didn't help. Car still needs jump randomly.

I say enough... take to dealer. they say it needs $530 of wiring harnesses in the tailgate before they can start tracking down the battery drain (they also say battery and charging system is good).

I go. They replace the harnesses. say the can't find any drain. I ask around and am advised to look at the a/c clutch (I told the shop to check it) and the "handsfree control relay" or something. I don't think the 2004 has handsfree and in anycase I can't decipher that one.

$530 later, Backup camera works now (which I am happy about) and tailgate light works. I drive it home, park the car for 3 days. it starts up fine. I drive for 20 minutes, park for 2 (no a/c or radio or fan or anything running since I picked it up from shop) and it's completely dead. I have to unlock the transmission and push it out of parking stall to jump start it.

ideas? if the charging system checks out and the battery checks out... what else?

I asked another acura owner with a similar issue and she said:
1. Replace battery with Optima Red Top, whatever that is.
2. She said that didn't completely fix her issue, but she stopped using the "auto" lights feature and anything else "auto". Says that solved it.

Is this worth persuing? Or should I set it on fire and drive it off a cliff (assuming it will start)?

TIA for any advice.

P.S. I'm pretty good mechanically (work on my own bikes, guns, etc.) but electricity may as well be Voodoo to me. All I know about electricity is it calms me.

NBP04TL4ME

Not sure if the 04 MDX has it or not but if you search here on AZ, you will find that the HFL (Hands Free Link) or Bluetooth unit is fairly prone to failure and causing a parasitic drain on the battery. We had an 07 and it failed but fortunately is wasn't draining/killing the battery.

When you say dead - what happens when you turn the key?

007Acura

04 doesn't have hands free link that came out in 05.

How old is your battery? I would definitely change it if it is more than a few years old. I put an optima yellow top in my mdx. Amazon seems to have the best price.

NBP04TL4ME

Thanks for the clarification on when the HFL appeared on the MDX.
While I agree the battery may be the issue, I'm not convinced it might not be the starter itself or maybe the alternator?? Need to OP to answer my question above.

Optima batteries used to be a big deal, now as I understand it, not so much. Manufacgturing process has changed and I believe I heard they are now being outsourced to another manufacturer. FWIW, I have always been a big fan of the Diehard line of batteries.

1KPerDay

Car sometimes cranks over weakly for one or two cycles, slowly and not enough to start, sometimes just a clicking sound as not enough power. Acts like battery is REALLY dead. Lots of repeated clicking sounds from the dash (I assume relays attempting to open/close as car starts or something).

When jumping, I usually have to wait 30 seconds or so after batteries are connected before my car will crank over.

1KPerDay

So, to be clear... is it possible that the battery (which is at least 5 years old) checks out fine by the auto parts dude's tester and the dealer's tester, but still would need to be replaced?

I assume there's a way to check alternator output and the dealer would have checked it... maybe I'm assuming too much.

The fact that it starts fine for days or weeks at a time and then randomly doesn't leads me to believe it's something like an intermittent draw on the battery rather than a battery or alternator issue. Do alternators sometimes fail "sporadically"?

1KPerDay

Anyone use something like this?
PriorityStart - Stop Dead Batteries on Cars & Boats [Priority Start! Battery Protector]

I assume that if it is indeed a battery or alternator issue, this wouldn't help, correct?

NBP04TL4ME

So if it is cranking weakly and sometimes just clicks, it likely isn't the starter and a weak battery. If you are having to wait 30 seconds or so, then I would say you have drained the battery to a very, very low power point. This is typically referred to as deep cycle discharge and there are batteries specifically made for this. Car batteries don't fall into this category and typcially deliver high voltage short bursts (like starting a car) and don't discharge a lot of their capacity. Deep cycling an automotive battery isn't good and may in fact induce or show signs of a dead or dying cell within the battery.

It is possible for your battery to have faked out both the Auto parts and dealer's testing. Have heard about this from other members here on AZ. There is a way to test alternator output, but not sure how the dealer does it. Why not ask them? Years ago, I had to have multiple alternators bench tested, which consisted of mounting the alternator on a bench, hooking up a drive belt and measuring output. I assume (yeah, I know) in the years since there is another or easier way to do this. Perhaps its as easy as measuring output while in the engine bay. Not sure - it's been a long time. I have not seen or heard of an intermittent failure of an alternator.


Never hear of this poduct and based on what I just read, it sounds like this battles parasitic drain.

As you mentioned your battery is 5 years old and it certainly sounds like you have drained it to a very low voltage state (deep cycled) - not good for battery health. If it were me, I would start with a fresh new Diehard and go from there. Going to guess you will be good to go for quite some time.

FactoryMDX

Interstate which if you don't know is a premium brand of battery should be replaced every 3 years... $110/3 = $36 a year..

I'm sure ppl blow more money on something less valuable than that daily.. a battery is enabling you to go wherever you want in your mdx, just replace it...

1KPerDay

Thanks for the feedback. Going to replace battery... any advantage to the optima red top over the diehard or interstate?

If so, which of these is correct?

http://www.amazon.com/s/ref=nb_sb_no...optima+red+top

If not, what's the best/cheapest place to get an interstate (I assume DieHard is still a sears-only brand)?

NBP04TL4ME

Yes - Diehard is still a Sears only brand.

007Acura

Most batteries these days will get the job done.

If you want an . They all come with adapters that you put under the battery so it fits properly.

I got the yellow optima this past March because they had a promotion where you get a free charger valued at ~ $110. If it wasn't for that I probably would have just purchased another diehard which lasted me 5 years. My yellow top however has been doing a great job.

1KPerDay

is there a particular model of interstate required, and where would you purchase?

NBP04TL4ME

Model -

Interstate Batteries Results Page - Automotive / Truck 2004 Acura MDX

I would likely go with the Mega-Tron Plus because it has more CCA but don't know your climate a described below the Mega-Tron Plus and Mega-Tron II. The MT7 AGM seem like a little overkill and pricey but don't know your particular usage.

Where -

http://www.interstatebatteries.com/D...t.aspx?dist=50

And again I would cross shop against the Diehards........

PaulAWD

Just replace the battery. My 2004 MDX eat batteries like crazy. 250K miles and I'm on my 4th battery. They work fine for a few years then turn into garbage. The ground for the back camera wears opening and closing the liftgate so many times. You can splice the wire together in about 15 minutes instead of a new harness if any body ever needs to do this

NBP04TL4ME

What kind/brand of battery are you using?? 4 batteries in 10 years sounds like a lot, but you have rolled up a lot of miles too. Just curious is you are getting the replacements by using a prorated warranty from the previous one.

PaulAWD

First 2 were Acura batteries. No warranty because they would only do it if they installed the battery themselves. It was $150 to spend 5 minutes putting it in. Discounted the acura battery was only $80. after the second one failed I went to a 6 year Interstate that work great until not long ago. Same deal, Warranty was a big pain, so I gave up and bought a discount battery from Walmart that is working stronger than all the others, lol.

NBP04TL4ME

Good luck with your Walmart battery.

1KPerDay

Thanks for all the help. Much appreciated.

NBP04TL4ME

NP - that's what a forum like this is all about.

1KPerDay

Well after sitting for a few days, old battery was dead again. I picked up interstate megatron plus and got it installed. Started right up of course. I'm going to leave it for a few days and see if it starts before I start using the car regularly again. Cross your fingers!

NBP04TL4ME

Good Luck!!

1KPerDay

Well, it seems to be okay. Though I still park it nose out in case I have to jump it.

Thanks for all the great advice!

NBP04TL4ME

PaulAWD

LOL, have some faith in the Interstate