What is this? and why is it running my battery down?

[Midlothian Electric]

Everytime I connect the battery, the device circled clicks. It's on the driver's side firewall

[john]

Looks like a TCS relay. Most people throw all of that system away.

[Longhorn Man]

Originally Posted by john

Looks like a TCS relay. Most people throw all of that system away.

Just unplug them.

[ibad57]

it could be horn relay unless horn is working properly

[kbs71]

It's not the horn relay there ain't no red wires going to it.

[hvychve]

I am gonna make a stab at this one, I had another guy with the same question about a year ago.
The Horn Relay wire colors are going to be Black, Red and Dark Green.....
I have included a few photos of what I think this other relay is, I have colors for one of the relays but not the other, never the less, you may be able to figure which one it might be.
Check your wire colors and see if these are on it: Pink, Orange, and Two Dark green wires.... if these four wires are there and match , this is an Anti-Dieseling relay....I think
On Automatic equiped Vehicles that had A/c. what it does is actually turns on the A/c compressor clutch for about three seconds after keys is switched off, this allows extra load on the engine to keep from dieseling....
There is another photo of a relay that is sorta in the same purpose, it plays a roll with manual transmission models, operates a few function of the vacuum advance. The dist. vac. adv. has been eliminated in the low forward gears ,the control of the vacuum advance is accomplished by means of a solenoid vac. sw. which is energized by grounding a switch at the trans.thus , two seperate throttle settings are now possible-one for curb idel and one for deceleration hydrocarbon control.(emissions). This type of system is incorperated for a couple reasons , lower emissions at lower obrainable idle speeds and for dieseling purposes. if the idle is allowed to be lower , this in turns allows for the lack of dieseling....so to put it mildly, These may be removed, hopefuly the wire colors might match, I seriuosly doubt tht this had the solenoid mounted on the throttle, but It may have...
components involved would be : Time-Delay Relay, Reversing Relay, Note that in the diagram, it has switched power from ign. sw. to both relays, So it should not have power unless key in accessory, which dont make sence to me, however, maybe some of this may help.....

[72k20+afew]

don't know what it is but i just threw one out maybe i could dig it outa the garbage for ya the truck still runs must not be important

[oldgold70c10]

A lot of neat guesses, but it looks like the TCS, or Transmission Controlled Spark system relay. This was a gimicky first-gen emmisions control device that only allowed distributer vacuum advance in high gear when the engine was warmed up. Like LonghornMan says, just unplug the wires. You'll probably find a {leaking} vacuum valve in there somewhere too. Just remove it and route your vacuum advance hose directly to the port on the carb like nature had intended.

[VetteVet]

I agree with everybody that it's a tcs relay. That doesn't explain why it clicks when you hook up the battery unless there is a switch stuck somewhere.
Unplugging the relay should fix the current draw though so you won't run the battery down.

[hvychve]

vettevet, I can tell you dont know, you must be new