Install switch to cure radio battery drain issue.

CraveyDockett · Jul 18, 2024

Hey All,

Just picked up a 2021 1500 5.7 that used to be a rental. It seems to be plagued with the high-amp battery drain issue talked about at length on here. After reading almost everything I'm curious: suppose I were to yank fuse F44, 20A yellow (Radio/ DCSD/ Telematics) and install a little bitty switch instead? It would have 2 leads that went into the fuse box where the yellow F44 used to be and could be mounted to the right where the plastic trim panel begins to curve under.

When you leave the truck just flip the switch down so the battery drain stops. When you return, open the door, get in, flip the switch up and start the engine.

Thoughts? Would not having a functional fuse keep me from opening the door or cause some other issue?

Thanks!

chopperman1 · Jul 18, 2024

No, you cannot replace the fuse with a switch. The fuse is there to protect the wiring. If you are experiencing parasitic draw you need to troubleshoot it vs guessing it's your radio.

CanRebel · Jul 18, 2024

I agree with above. That is a really bad idea.

If your truck hasn't been changed at all. I would first check if there is an update for firmware. I recall that being an issue for some.

John Schmidt · Jul 19, 2024

If you really wanted to, you could put a switch (location tbd) in series with the fuse. Just make sure it's a switch that can handle the DC current rating of the fuse (or greater).

zrock · Jul 19, 2024

find and fix the issue and find the actual draw instead of guessing. Im also thinking that installing a switch will cause other issues as the radio is integrated with more than just sound.

Jas34 · Jul 19, 2024

Pull the fuse every time you leave the truck and verify that stops the draw. If so, then at least you know which circuit it's on. Then divide and conquer the circuit from there (wiring diagram in hand) and locate the source and fix it. Do not replace the fuse with a switch. Find and fix the problem instead.

Also, before you go chasing down a rabbit hole based on something you read, is your battery good and charging system and starter working correctly? How much is the draw? Is it constant or intermittent? Is it running the battery down overnight?

Slinge · Jul 19, 2024

I wouldn't think you would want a switch under the hood. You probably rather have it inside the truck between the fuse and the radio.

markabby · Jul 19, 2024

Jas34 said:
Pull the fuse every time you leave the truck and verify that stops the draw. If so, then at least you know which circuit it's on. Then divide and conquer the circuit from there (wiring diagram in hand) and locate the source and fix it. Do not replace the fuse with a switch. Find and fix the problem instead.

Also, before you go chasing down a rabbit hole based on something you read, is your battery good and charging system and starter working correctly? How much is the draw? Is it constant or intermittent? Is it running the battery down overnight?

i'd do one fuse at a time....or maybe a bad diode in the alternator? Most auto parts stores will check that for you.

There's some youtube videos on how to hunt down a battery drain too.

mtnrider · Jul 19, 2024

Have you load tested your battery to make sure it is good? A bad cell in a battery can cause all kinds of issues including modules not shutting down correctly leading to additional drain etc.. If you haven't I'd get them load tested before you go down this rabbit hole.

.

JW2 Innovations · Jul 19, 2024

Might want to try this LINK for parasitic draw troubleshooting

RamDiver · Jul 19, 2024

mtnrider said:
Have you load tested your battery to make sure it is good? A bad cell in a battery can cause all kinds of issues including modules not shutting down correctly leading to additional drain etc.. If you haven't I'd get them load tested before you go down this rabbit hole.

.

^^^^^^

This is the best advice I've seen here, besides, just fix the problem instead of using a bandaid approach.

A digital battery load tester will often miss a flakey cell. A free test is not always the best solution.

I would suggest you splurge and spend about $20 at HarbourFreight, buy a toaster-style battery load tester and another $3 for a battery post/clamp cleaner.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Battery Terminal Cleaner

Amazing deals on this Battery Terminal Cleaner at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Make no assumptions about anything electronic, testing and verification are always the best approach.

.

Dean2 · Jul 19, 2024

RamDiver and others saying the same thing - Spot on. It absolutely AMAZES me how often this very basic advice has to be repeated. Guys fire the parts cannon or come up with Arcane fixes before they even do the very basic diagnostic work to find out what the actual problem is.

CraveyDockett · Jul 19, 2024

Jas34 said:
Pull the fuse every time you leave the truck and verify that stops the draw. If so, then at least you know which circuit it's on. Then divide and conquer the circuit from there (wiring diagram in hand) and locate the source and fix it. Do not replace the fuse with a switch. Find and fix the problem instead.

Also, before you go chasing down a rabbit hole based on something you read, is your battery good and charging system and starter working correctly? How much is the draw? Is it constant or intermittent? Is it running the battery down overnight?

Jas34, stock battery showed a 2A draw when the system was sleeping. I replaced the battery, cleaned the clamps, it load tested good using the toaster, the alternator is charging properly.

System draw is now somehow down to 114 mA which is hugely better than before but still higher than the 85mA draw that (I think) is preferred for a sleeping vehicle.

CraveyDockett · Jul 19, 2024

RamDiver said:
^^^^^^

This is the best advice I've seen here, besides, just fix the problem instead of using a bandaid approach.

A digital battery load tester will often miss a flakey cell. A free test is not always the best solution.

I would suggest you splurge and spend about $20 at HarbourFreight, buy a toaster-style battery load tester and another $3 for a battery post/clamp cleaner.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

View attachment 546954

Battery Terminal Cleaner

Amazing deals on this Battery Terminal Cleaner at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

View attachment 546955

Make no assumptions about anything electronic, testing and verification are always the best approach.

.

RamDiver, totally with you on this. I own both the post/cable cleaner and toaster and used both in my diagnosis.

Dean2 · Jul 19, 2024

CraveyDockett said:
Jas34, stock battery showed a 2A draw when the system was sleeping. I replaced the battery, cleaned the clamps, it load tested good using the toaster, the alternator is charging properly.

System draw is now somehow down to 114 mA which is hugely better than before but still higher than the 85mA draw that (I think) is preferred for a sleeping vehicle.

If you monitor the draw over a longer period you will likely find it keeps dropping. Deep sleep can take quite a while. Also, make sure you don't have your fob on you if you have push button start and smart entry.

CraveyDockett · Jul 19, 2024

Dean2 said:
If you monitor the draw over a longer period you will likely find it keeps dropping. Deep sleep can take quite a while. Also, make sure you don't have your fob on you if you have push button start and smart entry.

Ahh, good to know! Will do the Long Time Deep Sleep draw test this weekend.

And the key fob, yes. Every time I walk by with it the dash lights come on, like it's saying, "Oh boy, he's back. Let's go cruising!"

CraveyDockett · Jul 21, 2024

Update: A 2 hour sleep test today showed 0.040A. So the longer she sleeps the fewer calories she burns.

Dean2 · Jul 21, 2024

30 to 40 miliamp is very good. After 2 weeks parked it will drop even further as the fob recognition etc goes to sleep too. Also if you store it in a garage unlocked it will draw less. The security system has a slight effect too.

Dusty · Jul 22, 2024

If you start pulling fuses be aware there may be something else on that circuit regardless what it says on the fuse box cover. Also, it might keep reporting a fault because the PCM knows when a module isn't communicating.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 116044 miles.

Tominator223 · Jul 22, 2024

Do a phantom draw test. This will show how much is being drawn with everything off. If it’s more than .5volt something is a mis. The radio may not be turning off completely or a door pin is leaving light on or console light not turning off when it’s closed. It may be slightly more than.5 on the newer trucks ,but .5 volts was a rule of thumb on most vehicles . You can find the specific # in tech info. The way we used to test was pull the positive cable & test between the cable & battery. Turn off everything and close doors. If it has a under hood light unplug it. This should give you an idea of how much of a drain there is. In the cars I’ve done this with , I found a glove box light that didn’t shut off & a trunk light. Also cargo light on a truck & interior lights.

Install switch to cure radio battery drain issue.

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