I got my son a project truck, and we're trying to track down a problem. It has a parasitic draw of around 200-230 ma, which I have isolated (by pulling fuses) to the GEM. 176 ma of the draw is on a single wire leaving the GEM. I found a pinout diagram online for that connector and it says the wire is for circuit 792, the "battery saver relay output".

Pulling relays under the hood (near the battery) has no affect, so I'm guessing that's not where the battery saver relay is.

My question is: does anyone know where the "battery saver relay" is on this ranger? And how do I tell if the problem is the relay or the GEM? Any other ideas?

1997 ranger 4-cyl, 4x2 XL, 155,000 miles.

Thanks!

 

Welcome to the forum

First thing is that .20-.23amps should be a draw just after you shut off the key
And most of it will be from battery saver relay circuit and GEM

The GEM has a timer that starts when key is turned off and all doors are closed, after 20-30minutes it will OPEN Battery Saver relay and then "go to sleep"
At this time amp draw should drop to .03-.07amps(20-70ma), this is from computer and radios KAMs(keep alive memory) and Keyless Entry module(if so equipped)

So retest but WAIT 30min and then see what draw might be

In 1997 Battery Saver Relay should be in Relay box 1, which is above gas pedal area under the dash, there are several relays inside it

Diagram here: https://wiringdraw.co/wp-content/upl...n-explorer.gif

You could pull out Battery Saver relay and then see what draw is, but GEM will still be "awake" unless you wait the 30min


Batteries can have there own parasitic draws, shorted plates inside, its the usual failure mode for these types of batteries, can occur anytime after 3 years old, even sooner if they are over charged by failing alternator.
So always test battery first, disconnect it from the vehicle and put voltage meter on it, write down voltage, i.e. 12.45v, leave it connected for an hour, if voltage has dropped then battery has a short inside and will slowly drain on its own, even faster if it also being drained by .03-.07amp draw of vehicle

 

Thanks!

So now we're just watching the clock before checking again...

The battery looks maybe a couple years old, and it is not a quality battery (its the cheapest one available at Walmart). And its been through some abuse the last couple months since we got the truck. A door was hard to close, so the light got left on a couple times. I was unsure if the battery draining problem was a bad battery or a parasitic drain, which sent us searching for the source of the 200ma drain. If we have a parasitic drain problem, I'd just like to get it figured out before we go buy a new battery, so we don't abuse a new battery.

If the whole problem turns out to be a bad battery, that would be good news to me, because I already thought we needed a battery.

 

If you have the hood open for the test make sure you tape closed the pin that turns on the under hood light, or remove the bulb

Just test battery and see if voltage is dropping, it shouldn't

 

You were right. After sitting a while, the draw dropped to 9-13 ma. Its a base model xl, so it doesn't many options & electronics to keep powered up.

The voltage was dropping constantly on the battery with the truck just sitting in the garage. From full charge it would drop a few tenths of a volt within hours and drop to 8.5v in a couple weeks.

Walmart tested the battery a few minutes ago and said it was bad. They said it was 3 years old (and their cheapest one). I got a new battery, so we should be good to go now.

Thanks again!

 

Good work

Thanks for posting the update

 

I know this is an older thread, but thank you!

I recently went to start my '98 after it had sat in the garage for about a month and found the battery was down to about 10.5v. Charging it this weekend, the truck fired up no problem and I monitored the battery voltage a bit. Over 17 hours, the battery went from 12.46v to 12.37v. Measuring for a parasitic draw, my multimeter was showing 190-200mA not long after running. I isolated the draw to the #26 Battery Saver Relay fuse. When I pull it, it drops to about 80-90mA. Checking after 30 minutes, the amp draw is 84mA. 30 minutes after that, it was showing a 27mA draw.

Just throwing this out there, but is there anything else I should check for? Is it concerning if the battery is losing that much power over the course of 30 days.....or, maybe is that just how this older vehicle is?

This thread has certainly steered me in a better direction. Thanks!

 

Never the age of the vehicle, only the age of the battery

GEM keeps the battery saver relay ON for 30-45min after key off doors closed
So pulling it's fuse should cut that amp draw instantly
80-90mA is not that bad, 27mA is good, I assume no keyless entry?

"the battery went from 12.46v to 12.37v" was this with battery disconnected?

Best way to test a battery is to disconnect the Negative cable
Test voltage, write it down
Test voltage again after 6 to 10 hours, should be EXACTLY the same, if lower then battery is self draining

Car batteries last 5-6 years in normal operation, generally the end of life is they become self draining
New battery is 12.8-13.0volts
3 year old battery is 12.5volts
5/6 year old battery is 12.3volts and time to shop for battery sales

Car batteries are not made for long steady amp draws, under 100mA(0.1amps) is usually OK
Car batteries are made to provide high amps for starter motor(CCA), then to be recharged quickly right after
They do not like to be drained under 12volts

Deep Cycle batteries are used for long steady draws, but these provide lower CCAs

 

Answered your questions in red. Thank you for the help. Just being able to check the amp draw in real numbers correctly is reassuring. I'm thinking once the truck gets on the road and is used more regularly, the battery will be fine. Thank you for your help.

 

You have to wait at least an hour after charging to test actual battery volts, chargers or alternators heat up the battery and it will show a false slightly higher voltage, once it gets back to "room temp" it should show true volts
At 2 years old I would expect 12.6v/12.7v but all battery are slightly different

Keyless entry should be 0.03amps, 30mA on its own
Computer and radio memory, 20-30mA
So 50-60mA would be expected