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4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

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Old 02-03-2015
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Join Date: Jan 2015
Location: Anacortes
Posts: 3
Phantom loads

Hi, my first post ever anywhere so.....

Just bought a 1998 Ranger XTL 4X4 with 4.0 L engine and auto Xmission w/190k miles. Really nice condition and runs very well.

After it sits for a few days the battery is dead (new battery). I pulled the ground off the battery and inserted an ampmeter. There is a constant draw of little over an amp. Pulling fuses I find that fuse #25 - GEM & instrument cluster is drawing 260ma. Fuse #26 - Relays, Shift control module, dome lamps, & GEM is drawing 235ma. And Fuse # 29 - Radio is drawing 535ma. This is with everything off.

Are these normal? If not where do I go from here?

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Old 02-04-2015
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Join Date: Jan 2014
Location: Vancouver, BC
Posts: 7,573
I think 30 to 50ma is normal on computer assisted vehicles, .03 to .05amps, that would be computer memory and radio memory.
There are also alarm systems and keyless entry to consider.

Check the obvious, glove box light, under hood light, also check that all lights work, 3rd brake light, cargo light can draw power with a non-working bulb.

The 1998 Ranger will have a 20 to 45 minute power draw after key is turned off.
So hard to check power draws right away.
The modules stay "awake" for awhile after key is off

You need to hook up the amp meter without disconnecting the power as well, if you disconnect the power then the module giving you the problem may shut down(like it is suppose to when key is off) so you may not find the problem.
You can use a jumper cable; remove battery cable from battery, use jumper cable to connect battery and removed cable, start engine, let it run for 1 or 2 minutes then shut it down and remove key, now connect meter to jumper cable and battery cable before separating them.

Wait for 20-45min. check meter for drop, GEM will go to sleep and power will drop quite a bit.
Start in the engine fuse box.
Don't forget about the alternator, they can draw power when going bad, remove the B+ cable from the back, to test.
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Old 02-05-2015
Thread Starter
Join Date: Jan 2015
Location: Anacortes
Posts: 3
Ron, Thanks for the reply. When I find it (buried in a box somewhere) I'll install a meter shunt in series with the battery lead. That way the car won't recognize anything in the line. I should then be able to make an initial reading then wait for a couple of hours and check again.

Thus far it is isolated to the 2 GEM fuses and the largest current drain is the radio circuit. It is off but still drawing about 1/2 amp.

For now I just pull the 50 amp fuse that feeds the sub panel in the cab. A nuisance but it will have to do until I can sort this mess out.

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