Hi Guys,
This is my first attempt at posting ,so bear with me.
The subject vehicle is an 04 Acura MDX w/v6 engine /4wd/auto.
The complaints are intermittent a/c operation,loss of the navigation system screen and various instrument panel warning lights that would randomly come and go.
The only code present was for low voltage to the ABS that never reset after clearing.I also noticed that my Modis would keep giving me the "vehicle battery very low "warning.I ignored this ,thinking it was just a glitch.Big mistake!
The symptoms would rarely present themselves at idle,but would usually show up while driving after reaching about 10MPH.I graphed the scan data on a test drive and saw this
I had a charging system problem that was causing the symptoms because the problems would come and go with the low voltage data.Ah ,a bad altenator ,I thought.I have seen many Asian vehicles with crazy warning light symptoms before that was due to a bad altenator.Wrong . The altenator and battery checked out fine,when it was charging and no control circuits seemed to be lost when it was not charging.
My next thought was that the ELD was acting up and causing the problem.I was able to get the symtoms to occurr at idle long enough to do a voltage drop test across the ELD.There was none.zilch,nada.
Now I am scratching my bald head,and it finally dawns on me .Voltage drop.I test the altenator output wire between the alt. and the ELD first and it proved good.I then went to the neg . battery post and the engine block and it was good.Because it was handy ,I checked the altenator output wire where it feeds the under hood relay box to a body bracket bolt and saw this
Bingo .The high blips are due to the fan relay cycling rapidly,which I forgot to mention.
A quick look at the neg cable connection to the body showed what appeared to be a clean tight connection,but putting a wrench on it yeilded this result
Car fixed,me happy.Man I hope this post works,I don,t have the energy to do it again.
This is my first attempt at posting ,so bear with me.
The subject vehicle is an 04 Acura MDX w/v6 engine /4wd/auto.
The complaints are intermittent a/c operation,loss of the navigation system screen and various instrument panel warning lights that would randomly come and go.
The only code present was for low voltage to the ABS that never reset after clearing.I also noticed that my Modis would keep giving me the "vehicle battery very low "warning.I ignored this ,thinking it was just a glitch.Big mistake!
The symptoms would rarely present themselves at idle,but would usually show up while driving after reaching about 10MPH.I graphed the scan data on a test drive and saw this
I had a charging system problem that was causing the symptoms because the problems would come and go with the low voltage data.Ah ,a bad altenator ,I thought.I have seen many Asian vehicles with crazy warning light symptoms before that was due to a bad altenator.Wrong . The altenator and battery checked out fine,when it was charging and no control circuits seemed to be lost when it was not charging.
My next thought was that the ELD was acting up and causing the problem.I was able to get the symtoms to occurr at idle long enough to do a voltage drop test across the ELD.There was none.zilch,nada.
Now I am scratching my bald head,and it finally dawns on me .Voltage drop.I test the altenator output wire between the alt. and the ELD first and it proved good.I then went to the neg . battery post and the engine block and it was good.Because it was handy ,I checked the altenator output wire where it feeds the under hood relay box to a body bracket bolt and saw this
Bingo .The high blips are due to the fan relay cycling rapidly,which I forgot to mention.
A quick look at the neg cable connection to the body showed what appeared to be a clean tight connection,but putting a wrench on it yeilded this result
Car fixed,me happy.Man I hope this post works,I don,t have the energy to do it again.
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