Honda Passport 96

Keep draining battery dry. I’ve checked alternator, steel in good shape
What else could cose that problem?

:) A short or open circuit, it could be anywhere. Andie:)

Keep draining battery dry. I’ve checked alternator, steel in good shape
What else could cose that problem?


A multi-meter comes in handy, especially when testing for parasitic draw. You might want to search for people who have had the same problem.

How old's the battery and alternator??

Both times my battery has gone it was due to the alternator sucking LOTS of juice from it because it was dying.

I'd have your alternator tested *under load* - should be in the 14V range, if it's less then this, you're looking at a new alternator plus a new battery, most likely. They generally go together, at least that's been the case on both of my Rodeo's, a '91 & '97.

Also, check your battery cables, make sure there's no excessive corrosion, cracks in the clamps, etc.

a bad diode in the alternator is one thing that can cause battery drain. mike

I spent a good portion of yesterday working on a similar problem in my Jetta. I drained the battery while listening to the radio and changing a window regulator. I went through the last two batteries in about a year. I took the alt to NAPA and it tested bad. I was only getting 13V in the car running without accessories on. I put a new alt in and the voltages didn't change much. I checked for parasitic draw by removing the - cable from the batt and the + cable from the alt. I then put the multimeter in line with the - cable and - post on the battery and got no draw. I'm taking the car down to Advance to have the battery tested. Might have killed another. The original alt gave me 189K. You might test for the draw, then start removing fuses until you isolate the open circuit.

EDIT: I know this isn't Rodeo related, but I did some more evaluating this morning and found I blew the fuse in my multimeter last night. I changed the fuse and found I have a huge draw on the battery when the car is off. What a drag. The VW engine and tranny are bulletproof, but the electronics are horrible.

And get the alt checked.

Again, not Rodeo related, but may be helpful...

I took my battery down to Advance. It was low on charge but "GOOD" and they charged it. I went home, disabled the factory alarm which has been arming itself for ages intermittently, and hooked everything back up. Lo and behold, 13V across the terminals when off, 14V running, 14V running with accessories. The alarm module or associated wiring must be bad.

Anyway, have your charging system checked. If it's good, then you need to find your short. Good luck!