Relay ID...

[chazzone]

I've got an amp draw in my 98 2WD Ranger. I've tracked it to a relay that sits behind (to the right) of the ABS module in the dash (across from the GEM Module). Can anyone identify this relay?

Thanks,

-zz

 

[chazzone]

I'm thinking that it's the "Battery Saver" relay. Is replacing it sufficient?

 

[chazzone]

Apparently, it's not the Battery Saver Relay. I stopped by NAPA to get a replacement, and the one they brought out was a mini relay. The one I'm dealing with is a full size relay.
Anyone?

-zz

 

[chazzone]

There are 2 hot wires...green with a yellow stripe. Ring any bells?

-zz

 

[chazzone]

OK...confirmed that this is the battery saver relay. It was suggested that the GEM was the culprit (Ford Mechanic online...), but when the GEM is unplugged, power remains at the relay. Ideas?

 

[RonD]

To test battery drain you to have to wait 30-45minutes after key off doors closed.

GEM has a timer that OPENS battery saver relay after 30-45mins of key off doors closed

Try pulling Fuse #26 in cab fuse box, thats the power the GEM cuts off when it OPENS battery saver relay.

See if drain is still there.

Just after key off you might see .3-.7amp drain, too much long term, but normal just after key off

After battery saver relay OPENS, .03 to .07amps, which is normal for long term, this is for computer memory, radio memory and keyless entry(if so equipped)


And just a heads up, battery's can be self draining when they get a shorted cell inside.
Unhook either battery cable
Test its voltage, write it down
leave it for 4 hours, over night is better
Test it again, should be exactly the same

 

[chazzone]

Thanks Ron.
Did just that.
One thing I didn't do was fix the meter leads to the contacts. Every time I took a reading, I was starting all over again. After I fixed the leads, I found that the draw went down to .03 (after 45 minutes).
So, apparently I'm on a wild goose chase.
Doesn't explain why I'm on my 3rd battery in 4 months (original, cheap replacement, Optima Yellow Top).
Alternator checked out initially. So, I'll go back there and make sure it is charging.
Thanks for the reply.

 

[RonD]

Alternator/voltage regulator can get "stuck" at 14.5-14.9 volts out, which will overcharge and "burn out" a 12volt battery

Test battery voltage before start up. 12.3v to 12.8v is expected
12.8v is new battery
12.3v is 5 year old battery and time to shop for battery sale

After startup battery will be drained so voltage regulator should pump up output to 14.5 to 14.9v
After 5 minutes of "fast charge" battery will be charged up again and voltage regulator should drop output to 13.5v to 13.8v, this will not hurt the 12v battery long term and will keep it charged up

 

[chazzone]

That's exactly what I read. Voltage is 14.5 at start up. Then, settles down to 12.8. It's a new Optima Yellow Top.

 

[RonD]

12.8v with engine running means alternator is bad, system is running off the battery, not alternator

13.5v-13.8v engine running after 5-10 minutes is correct

 

[chazzone]

Took her out and drove her for about an hour. Came home, and it was charging at 14.5 volts. Gave it 10 minutes, and still the same. Fifteen minutes later...still 14.5.
So, I'm thinking voltage regulator (about $50 from Rockauto). Or I just buy a new 130 amp Motorcraft alternator. Pretty sure the automatic alternator will fit, and I'd like to have the extra amps for lights.

 

[RonD]

Yes, it could only be voltage regulator, it supplies the voltage to the rotor in the alternator, and thats what sets the output voltage

Do a quick test first, Key off
Unplug the 3 wire connector on alternator
Test battery voltage, says its 12.8volts

Test voltage on the Yellow wire on the connector, should be exactly the same, 12.8v, if not then that wire has a poor connection and would cause the higher voltage

Voltage regulator works by "electromotive force", easiest way to understand it is "pushback force"

Just after starting battery is drained, so it will take all the voltage it can get, for a minute or two then it starts to "pushback" it doesn't want so much voltage, so voltage regulator lower voltage(to rotor)
When you turn on the lights or blower fan to HIGH, pushback in the system drops, so voltage regulator sends more voltage until lights are powered up and fan is spinning at high RPMs.

The Yellow wire is voltage regulators connection to the "system", so if it has corrosion on its connections then voltage regulator is getting less pushback so it cranks up voltage

Bad battery can do the same, it never gets fully recharged, it wants more voltage all the time, which is bad for it, lol, I know your battery is new just mentioning it for future reference

 

[chazzone]

Thanks, I'll check. That might explain something that was going on last year. For a while, I'd see the alternator idiot light come on when I was driving. The gauge always showed normal, and when I checked voltage at the battery, it was always good. After a couple months, that stopped, and I never had any issues with low battery until a couple months ago. So, I never really dug into it until I started having a dead battery. The idiot light wasn't coming on and the gauge showed normal. So, I started looking for an amp draw. I drive a service truck most of the time, so this truck sits for up to a month at a time. Not good for it.

 

[chazzone]

12.8 at both... I changed the belt and tensioner a few years ago and used silicone grease on the connectors when I put everything back together. No corrosion. So, it looks like I'm in for a new alternator. This has always been a super reliable vehicle, and I don't really mind putting a little into her to keep it that way. Besides, 20+ years on an alternator isn't bad.

 

[RonD]

Battery Light is also the ON/OFF switch for alternator/voltage regulator, that circuit is the Light Green wire on the 3 wire connector

With key on 12volts from fuse panel is sent thru the Battery Light bulb to the alternator on that light Green wire
Since engine is off the alternator is essentially a Ground(low volts) so Battery Light is ON
But voltage regulator now has 12v on that light Green wire to use for "Startup voltage"

After engine starts up alternator is now producing 14.5v
So Battery light now has 14.5v from fuse panel and light Green wire is also 14.5v at the alternator, if a light bulb has the same voltage on both terminals no current flows thru it so............no heat and no light

If alternator volts drop below Battery volts, i.e. 12.8v, then battery light will start to flicker, the bigger the difference the brighter the bulb glows