Cooling fans used to come on when...

[rundmc]

Hey all -

I often keep my battery out of the car and on a trickle charger as my car is not a daily driver. The cooling fans would usually click on for a second when I would reconnect the battery to the car. They are brand new DMCNW fans and have been working great. Last weekend, I connected the battery and the fans didn't come on like they usually do. Is this a problem and what could be the reason? My fuse box has one of those old school fan fail relay boxes.

Thanks,
Mike

[rundmc]

And just to clarify - I have tested the fans with the A/C switch on and they do come on and cycle when the A/C is activated, they simply no longer come on for a few seconds when the battery is connected. I have not had the chance to test them coming on under engine cooling conditions, which is my primary concern.

[jmettee]

I wouldn't think anything of it. Probably just the relays momentarily closing & activating/energizing it when first connected.

[WelmoedJ]

In the fan circuit (original) you have three parts that work with the fans:\
- otterstat
- fan relay
- fan fail relay or subsitute wiring (with or without fuses)
check all these parts for proper functioning.

On the trickle charge, a remark:
If you have a modern gel or alike battery, don't trickle charge (actually this applies to all types).
As a result you will shorten the battery life.
If you store batteries for a longer periode of time, they will slowly loose capacity.
That's approx 1 Volt a week.
Charge the battery each couple of weeks (2-4 weeks but at least if the power is below 12V).
That will be sufficient to recondition the battery.

Mind that a fully charged battery still may show over 12 Volts of power, but when treated the wrong way often has too few Amps (current) to get the car going.

[sean]

Who's fanfail module are you running?

[rundmc]

It was installed by Grady for the P.O. before I owned the car. It is a grey box with two screw-in fuses.

[sean]

Well what I would do is with the battery connected, bypass the otterstat and pop in a 20 amp fuse to close the circuit and with the key turned to the first position the fans should come on, if they do I wouldn't worry about things. Put the wires back on the otterstat when done of course.

[rundmc]

Thanks, Sean. I will try that this weekend.

[Elvis]

...
If you store batteries for a longer periode of time, they will slowly loose capacity.
That's approx 1 Volt a week.
...


Huh ?
What do you mean ?

[WelmoedJ]

If you store batteries for a longer periode of time, they will slowly loose capacity.
That's approx 1 Volt a week.
[Quote/]

[QUOTE=Elvis;25706]Huh ?
What do you mean ?

Exactly what it says...
Try it, disconnect a battery and let it sit.
Check Voltage at 7 days intervals and you will see a drop of up to 1 Volt a week.
Connected batteries may drain quicker than that, but all will.
Quicker discharge usually is because of "hidden" users, like 'always on' alarm systems.

[Bitsyncmaster]

[Quote (Originally by WelmoedJ)]
If you store batteries for a longer periode of time, they will slowly loose capacity.
That's approx 1 Volt a week.
[Quote/]



Exactly what it says...
Try it, disconnect a battery and let it sit.
Check Voltage at 7 days intervals and you will see a drop of up to 1 Volt a week.
Connected batteries may drain quicker than that, but all will.
Quicker discharge usually is because of "hidden" users, like 'always on' alarm systems.

I must admit that I have never tried this but I don't think a good battery will drop the voltage like that. If the battery just came off the charger (or engine was running) it will hold a higher voltage (> 13 volts) for a few hours. So you would want to test your voltage starting the test well after running the car.

I've read others claim that when the battery voltage has dropped to 11.6 volts (?) that the battery is fully discharged. If that were the case, you could not start your car after sitting for a week.

[WelmoedJ]

I have a friend's battery over here.
He claimed that after a week his car would not start anymore.

Facts:
- The battery has been bought about a year ago.
- The car has been driven regularly.
- During the winter it sat for about 3 months.
- During the sitting the battery has been recharged every 3 weeks.
- 4 weeks ago the battery couldn't turn over the engine as quickly as before and fire the engine.
- A test showed a drop to 6 Volts
- At the supplier's the battery has been recharged showing 14.6 Volts
- Battery has been left disconnected to check "natural" drain.
- After a week the battery showed 13.8 Volts
- Two weeks thereafter it showed 12.6 Volts.
- Today (a week later) it showed 12.15 Volts

As the battery is not connected, this demonstrates there seems to be a drain regardless of it being connected or not.
The battery supplier also confirms there are natural causes for battery drain.
IMO the drain also depends on the internal condition of a non connected battery.

[Ron]

IMO the drain also depends on the internal condition of a non connected battery.This is probably what was wrong with your friends battery new or not, salesman or not ;-)
I have had several batteries sit on a shelf over a month after they sat who knows how long at the auto parts and fire bigblocks right up. Think of those in WalMarts....
Actually a good battery, if not drug down too low will build itself up some in decent weather.

[Bitsyncmaster]

- At the supplier's the battery has been recharged showing 14.6 Volts
- Battery has been left disconnected to check "natural" drain.
- After a week the battery showed 13.8 Volts


Something is wrong with those numbers. A battery will not read 13.8 volts after a week. It should read about 12.6 to 12.8 volts with a new fully charged battery.

Try your test on your battery. If you get the same results I would say your meter is bad.

[WelmoedJ]

Good advice, Dave.
I'll unhook the battery after the weekend and test both meters.

[nofear365]

I had my DeLorean in storage for 10 weeks with the battery disconnected. When I reconnected the battery the volt gauge crept up to around 8. I turned the key and after a few slow turnovers, she fired right up!

If I had my battery connected for the 10 weeks it would have been dead. My Bosch battery is around 3 years old now.