Jump Starting Van Everyday

[thobac]

I have an 89 Econoline 150. I've changed the Alt and Batery thinking that they were the problem for having to jump it every morning. It fires right up througout the day, it's just in the mornings I have to jump it. Does anyone have any idea of what the problem can be? My next replacement is the Voltage Reg. HELPPPPP! Send reply to arandm@msn.com please?

[Selectron]

I don't think the voltage regulator will prove to be the cause, but you can do a basic check on it very quickly if you have access to a multimeter. With the engine off, measure the voltage at the battery terminals and you should see around 12.6V. Now start the engine and that voltage should climb to thirteen-point-something volts. Now rev the engine a little and it should climb to around 14.2V and then it should hold steady at that voltage, regardless of any further increase in engine speed. If that all works out as expected then it tells you that the voltage regulator appears to be functioning normally.

More likely is that you have an excessive current drain whilst the vehicle is parked. It is normal for some current to flow whilst the vehicle is parked - there would typically be some current flowing to the radio, to maintain the radio memory settings, also to the alarm circuit to keep it powered whilst it is in standby, and maybe also maintaining the memory settings on some of the electronic engine management modules. My Escort diesel has a current drain of 30mA (milliamps) whilst parked. That's 0.03 amps.

You can measure the current drain by switching your meter to the current range (DC amps). You don't know what current you will find, so always start out on the highest range, which is typically 10A, and that way you will avoid overloading the meter. Okay, so disconnect the connector from the battery negative terminal, and then connect the black meter lead to the battery negative post, and the red meter lead to the connector which you just removed. Now set the alarm, and wait a minute or so for everything to settle down, and then take note of the current indicated on the meter. I would expect to see a reading of between 0.03 and 0.05 amps - that's 30mA to 50mA. In your case, if the battery is draining overnight, then that figure will be much higher.

If you don't have a meter then you can use a 12V test lamp instead (doesn't matter which way round the leads go) - hook it up as described, and if it lights very dimly or not at all then that indicates little or no current flow, but if it glows brightly then that indicates a high current flow.

To find out which circuit is responsible, leave the meter or lamp in circuit and then de-activate the alarm and then start removing fuses one at a time. If pulling a fuse makes no difference to the current drain then put it back in and move on to the next one. Continue working through them all until you find the culprit by a process of elimination, and you would then investigate that circuit further to determine exactly which item within it is causing the excessive drain. Likely culprits would be interior lighting circuits, especially hidden lights such as in the glove box, etc. - they may not be switching off when the door is closed. Somebody had the same problem a week or two ago, I think it was on the Crown Victoria forum, and it turned out that the compressor pump for the air suspension was intermittently activating overnight, and draining the battery. He got lucky because he just happened to be close by when it kicked in so he heard it but otherwise that would have been very difficult to track down, because it only did it every so often. Therefore, at all other times, the current drain reading would have shown a perfectly healthy few milliamps. If your problem is also intermittent then it could be difficult to locate, but if it's a steady drain it should be quite straightforward.

Whilst you're doing that testing, don't switch on anything which could cause a current drain above 10 amps, or you'll blow the fuse in your meter, so don't switch the headlights on, nor try to start the engine or anything like that - just remove and replace fuses.

[thobac]

I don't have an alarm though.

[Selectron]

Okay, that's no problem - it just means that your residual current drain whilst parked will be less than it would be if you had an alarm - it doesn't make a great deal of difference though. You can still expect to see a drain of 20mA or 30mA or so though, which will be the current which powers the clock (if you have one), and the radio memory and maybe the memory in some of the engine control modules.

When you test the residual current, just switch everything off beforehand as you would normally when you park the van, and also close all doors, so that you get an accurate indication of the current which flows whilst the van is parked.

[thobac]

Ok I will have that looked at as I don't have any of those tools myself. Thank you and I will be intouch. Have a good week my friend and once again thanks!

[Selectron]

I don't know how much of a problem it is to arrange the jump start each morning, but if it makes things any easier, at least until you get this fixed, you can disconnect the battery negative connector each night instead, then just reconnect it each morning.

That way, your own battery will not lose its charge overnight and the van will still be able to start itself in the mornings.

Or, if you can locate the main fuse for the vehicle, removing that each night and putting it back in each morning should have the same effect - depends if the excess current drain is on the far side of that fuse, which it almost certainly is.

Both of those methods would mean that your clock would lose its time, and the radio would lose its preset memories, so you may not want to do that, depending on how much of a problem it is to arrange that jump start each morning.

[Selectron]

I was just thinking, it really would be a good idea if you could take the battery out of circuit overnight, either by disconnecting the negative terminal or by removing the main fuse. The reason for that is that a vehicle battery is designed to provide a very high current, very briefly, as it operates the starter motor but they simply are not designed to be repeatedly deeply discharged - which is what is happening to your battery each night - and that will be shortening the life of the battery.

Also, alternators aren't designed to cope with the demands of recharging a deeply-discharged battery on a daily basis - and that is what is being expected of it each day after the battery has discharged overnight, so it's also placing undue strain on the alternator, rectifier and the voltage regulator.

You might be saving yourself from some potential headaches further down the line if you could arrange to take it out of circuit each night.