battery drain mysterious clicking noise

So I have a 2003 Tacoma TRD , 6 cyl, manual transmission.

Recently having some issues with a dead battery, thought it was from it not being driven much which seemed likely, but then put a new battery in and it died too. Parasitic drain, seemingly. A mysterious clicking noise ha been heard , when the truck is completely turned off. As in the clicking noise just came on on its on even though the truck had not been turned on at all, whatsoever. Jumped it, truck starts up just fine. Been driving it and seems to be holding, but I am waiting for the the mysterious clicking to come on again and eventually drain the battery - any thoughts ?

 

how many total mile ??

any recent repair work .........???

any upgrades new accessories installed ??

disconnect new battery completely.............................even tho dead new batt should recharge

disconnect ALL accessories b4 reinstalling a good batt

crank then determine if parasitic drain is from OEM wiring harness................or accessories

 

134k miles, no recent repair work, no aftermarket anything on it.

 

oh and I tried to hook it up the diagnostic code reader and it wouldn't connect at all. Nothing. That has worked in the past no problem.

 

Use voltmeter in series with battery cable to check for parasitic drain.

Also, any problems with the ignition key? Mushy, problems getting key out, etc? Maybe ignition is not completely de-energizing when you turn it off.

 

Clicking is probably something magnetic - relay, solenoid, A/C compressor clutch... Disconnect the negative battery cable. Repeatedly touch the cable to the terminal to see if you can trigger the clicking sound, then try to locate the sound. This method doesn't work on newer vehicles, but in a nearly 20-year old 1st gen it can save you some time isolating the problem.

 

hmm will try the disconnected neg cable touch protocol, see what happens.. thank you.

no issues with ignition key at all.

 

Does the charging system light turn on when the truck is running? It would be a red, battery shaped light on your gauge cluster.

I would definitely take Wsidr1’s advice and use a voltmeter to test the system. Here’s a good video if you’ve never done it. https://youtu.be/LGB6ZEjGm7Q

 

my gut is telling me that you have an aftermarket alarm installed and what you are hearing is the relay for the disconnected horn cycling, but… I am not there to confirm or deny, just going off of your description. When I have some time I will save if I have a power distribution wiring diagram I can upload to save you some diagnostic time.

 

Zero aftermarket anything on the truck other than suspension.

 

New batteries sometimes fail!

 

near 20 year old vehicle

ALL owners have absolutely nothing done to vehicle..........hard to believe

no one is tryin to place blame/fault...................no 1 guilty

if NO aftermarket

then the OEM wiring harness is rubbing against the frame or wires in the harness

are contacting each other at some point