S/C Coolant Pumps

Some of you may or may not have this situation - when my truck is off, after an unspecified amount of time the S/C coolant pumps come on. I am under the assumption from reading other posts that this is due to the S/C pump wiring being connected to the Fuel Pump circuit; and since the ECM will activate the Fuel Pump when the truck is off at times for testing that this causes the S/C coolant pumps to activate as well during the self tests.

It's not a big deal and I only notice occasionally when in the garage that my truck is "alive" by the whirring sound of the S/C pumps coming on randomly.

So I happened to be looking at the main fuse block in the engine compartment and I am assuming (bad) but need clarification that the yellow wire in my photos is that of the S/C pumps/etc being connected to the EFI 10A fuse.

What I am thinking is if the empty fuse slot above the EFI fuse is an option that if I put a 10A fuse there and change the yellow wire to run off of that if it will put an end to my S/C coolant pumps randomly coming alive when the fuel system self tests.

I plan on testing this out, but if there is someone that knows I absolutely should not, speak up. I am planning to add a 10A fuse the to black slot where the green arrow is.

My concern is also that, in changing this yellow wire to the empty 10A circut that the pumps will not function properly while the truck is running resulting in an overheat situation with the S/C.

Yay or Nay?

 

I'd leave it. Toyota specified the fuel pump fuse for a reason... probably, so if the pump screws up, it'll blow the fuse & the truck will stall so you don't hurt it by filling it with hot compressed air (detonation, melted pistons...)
It's not like it'll kill the battery- mine only ever runs for 1 minute max (probably a lot less, actually)

 

I'm probably going to err on the side of caution then and leave it as it was installed.

 

If your that worried about it you could unhook it. Then use a fused power source to a new relay, then to the sc pump and install a switch wire to the relay (recommend using the key switch so your don't forget to cut it on) that way its only on when the truck is on/off when off. If its not killing the battery I wouldn't mess with it.

 

Ford Lighting uses a similar pump. However, it is better. Also, if you inspect your pump closely, it might still have the "Ford" symbol on it. Earlier models did, while not sure if the later models do. They pumps on the TRD s/c have been known to stop pumping, even though they are energized. Some just plain stop working.

Even though it is off topic, since you mentioned the pump, I figure it relevant for you in the possible future. .

 

Thanks, I was wondering about that. My pump is still working but the sound of it pumping has changed since it was new and I really think offroading is a little rough on it, bouncing around and all.

 

Just sharing the knowledge.