97 Base battery drain

[OldMacTech]

My 97 base doesn’t get driven that much, drove it a few miles the other night. A little hesitant to start. Two days later, no start, barely nudged the starter. Charged it up, good start. Alternator putting out 14v+. Next morning, no start, down to 2 volts. Battery is 4+ yrs so I replaced it.

Same symptoms after new battery. Checked for stray draws and seems to be a 2amp draw (.2 on my DMM)

I’ll start pulling fuses tomorrow, but oddly when I put my charger on the re-charge, the drivers window went all the way down.

Suggestions please?

[JFP in PA]

Start pulling fuses................

[OldMacTech]

No effect.

This car has always hummed a bit after turning off. Sorta like a softer sound similar to a microwave makes but not as loud.

Curuiosly, reattaching the trickle charger to both windows go all the way down.

Also, my top is permanently dis-engaged and only works manually. Wondering if top sensors are seized somehow?

Car runs and drives, alt puts out 14+ v. Possible the new battery is defective?

[JFP in PA]

Originally Posted by OldMacTech

No effect.

This car has always hummed a bit after turning off. Sorta like a softer sound similar to a microwave makes but not as loud.

Curuiosly, reattaching the trickle charger to both windows go all the way down.

Also, my top is permanently dis-engaged and only works manually. Wondering if top sensors are seized somehow?

Car runs and drives, alt puts out 14+ v. Possible the new battery is defective?

It sounds like you still have parasitic drain on ANY battery, you should only have a 40-60 mA draw on the battery after the car is shut off.

[OldMacTech]

Major voltage drop.

Every thing off, doors closed, no key, frunk light disconnected, interior lights disconnected, radio off.

Every 45 sec the voltage drops nearly 1/2v but after 15 secs returns to full voltage but a few volts less than before. Went from 12+v to under 9v in about 2 hours.

Almost has to be alarm? I’ve never had the alarm go off in the 5-6 yrs I’ve owned)

Also, one time I had rodent issues in the engine compartment but once fixed, no problem.

[JFP in PA]

Originally Posted by OldMacTech

Major voltage drop.

Every thing off, doors closed, no key, frunk light disconnected, interior lights disconnected, radio off.

Every 45 sec the voltage drops nearly 1/2v but after 15 secs returns to full voltage but a few volts less than before. Went from 12+v to under 9v in about 2 hours.

Almost has to be alarm? I’ve never had the alarm go off in the 5-6 yrs I’ve owned)

Also, one time I had rodent issues in the engine compartment but once fixed, no problem.

The alarm is fused (should be E1 or B8), so you should have seen that doing your fuse pull diagnostics.

[OldMacTech]

Was getting inconsistent amp reading from my multimeter, turns out one of the lead cables is frayed. Switched to an older one and the readings are still odd.

.10 amps on 10a setting between the disconnected negative at full rest. 45 seconds or so jumps up to 3.10 amps. Fairly dramatic jump.

Pulled the alarm fuses, horn, cig lighter, doors, radio, dome lights, etc. no Change.

Alternator voltage regulator diode maybe?

Sat in the car for awhile expecting at least a mild hum from 3 amps-nothing.

[JFP in PA]

Originally Posted by OldMacTech

.

Alternator voltage regulator diode maybe?

You can always disconnect the alternator power lead to find out

[OldMacTech]

Yep, guess I’ll have to.

Probably do the fuse pull again before, and look at the relays.

[OldMacTech]

After replacing DMM probes I went through the fuse panel again and E4 seems to stop the drain. E4 is Seat Back Control, right side.

Oddly my seats don’t appear to be connected to anything electrical….
I did have surgery done on the right side to to repair a dent. Maybe something is grounding from that?

[JFP in PA]

Originally Posted by OldMacTech

After replacing DMM probes I went through the fuse panel again and E4 seems to stop the drain. E4 is Seat Back Control, right side.

Oddly my seats don’t appear to be connected to anything electrical….
I did have surgery done on the right side to to repair a dent. Maybe something is grounding from that?

Possible.....

[Gilles]

Originally Posted by OldMacTech

I went through the fuse panel again and E4 seems to stop the drain. E4 is Seat Back Control, right side.

Out of curiosity, is the back of the seat leaning against the firewall?

[OldMacTech]

Turns out my seat backs to have an electric adjustment- mine hasn’t functioned since I acquired it so kinda forgot. Duh!

After pulling the right side fuse the parasitic drain relented. Took the new battery back to the store, now tests bad so left with a new one. Held a charge overnight.

Not sure how to inspect of remove the switches from the seats to test. Seems that the passenger mirror is on the same circuit so the defect may be related to the repair I had done to that door and mirror awhile back.

[997_986]

POSES recommends removing seat first

1. Remove switch -2- from the seat. Unscrew fastening screws -1-. Pull switch -2- upwards and remove forwards -arrow-.

2. Unscrew control unit -4- in conjunction with seat memory fastening screws -3-. Remove control unit -4- and fold it forwards. Pull out the plug -arrow- together from the control unit. Unclip the plugs starting from the right, natural, blue, black.

3. Plug connection -6, 7, 8- without control unit seat memory Pull apart the plugs underneath the seat -6- seat backrest adjuster, -7- lumbar support, -8- backrest and separate the cable ties for the cable.

4. Cable routing between seat cushion and seat frame. -A- Seat cushion -B- Switch -C- Cable Pull out the plugs one after the other through this opening.

[wiebuschk]

My battery was being drained by the Rectifier diodes in the alternator.

[997_986]

Originally Posted by wiebuschk

My battery was being drained by the Rectifier diodes in the alternator.

Interesting, how was that analysed?