auxiliary water pump

[TchTchr]

It has been discussed in other threads, but I thought the guys at the top may pay more attention here. Where on the switch would I wire an auxiliary water pump. Also, where should I get 12 volts from?

Thanks,
Brad

[greasedltn]

I would wire the auxiliary pump to a switched power lead from your fuse box, through a relay and switch so you could controll it yourself. You can wire from a switched lead in the fuse box to a toggle switch then to the relay post #85. Post #86 to ground. Battery lead to post #30. And post #87 to pump.

[Clay]

I would wire the auxiliary pump to a switched power lead from your fuse box, through a relay and switch so you could controll it yourself. You can wire from a switched lead in the fuse box to a toggle switch then to the relay post #85. Post #86 to ground. Battery lead to post #30. And post #87 to pump.

Why does it have to be that complicated?
12 to switch to pump is how i ran mine...

[greasedltn]

I believe in using relays to protect the truck wiring, I also don't know what the amp. draw is for the pump. I just like being safe and wiring's like second nature to me. I didn't think it was too complicated but you are right, you could just put a switch and go with it.

[Jack_Toepfer]

Relays are and I think "should be" common practice, but I never seem to find the time to use them on my own stuff
I won't hack on someone else's truck though... so they get all of the fancy wiring. lol.

[Marv]

I've always just thought of relays as good, cheap insurance when it comes to wiring in vehicles.

Guess that's why I always use them...

[skyskijason]

Relays are good policy - but at 2.5 amp draw of coolant pump, not really necessary. A fuse at the 12v source (to protect entire circuit) is sufficient.

Sorry for such a late entry on this...

[Clay]

Relays are good policy - but at 2.5 amp draw of coolant pump, not really necessary. A fuse at the 12v source (to protect entire circuit) is sufficient.

Sorry for such a late entry on this...

only a month late

[Jack_Toepfer]

Would a key-on power source be a bad thing? I don't see a problem with having the pump on all of the time, unless you're trying to kill the system entirely, then you'd just un-plug it.

[Marv]

Would a key-on power source be a bad thing? I don't see a problem with having the pump on all of the time, unless you're trying to kill the system entirely, then you'd just un-plug it.

Jack, I would think an in-line fuse at any 12V switched source would be fine. Just find one in the fuse box and put in one of the "add-a-fuse" holders from Autozone or advance.

Just make sure it's switched, otherwise it'd run even with the key off.

[Clay]

mine is switched and keyed. I turn it off this time of year and won't use it again till temps drop some in Oct. My tank gets plenty hot when its 100* outside.

[Jack_Toepfer]

switch and key.... good idea.

I'm working an angle on picking up a welder from a friend of mine, and when I do, the cover/guard will be complete... complete with a spot for the aux pump to mount directly to the guard (rubber mounted). The manifold isn't light... and getting a nice hinge that will flip out like I need it will have to be pretty strong. The pump doesn't weigh but a pound or so though right?

[TchTchr]

Finally getting around to putting the auxillary pump on. Correct - it is only about a pound. I have three of them scavenged from pick-and-pulls for about five bucks each. Look around the yards for Mercedes - both gassers and diesels - they are on the passenger side wheel well area.

[Jack_Toepfer]

Perfect, thanks!