I am planning to swap out the IC pump this weekend with the CM30 unit. How to wire the CM30 so it is on constantly when the car is running. Also what size fuse to run with this setup. Would 3amp be ok.
thank you.

 

Vadim added a very clean line for mine. I dunno the fuse, but can look it up. the install is very clean so it is hard to even see it.

 

I have an 03. Initially, it was wired to the acc battery in the engine compartment. Do not do this. It causes the relay for the acc. battery to burn out and is like $400. Some say they wired to an accessory fuse opening in the fuse box but I couldn't find one. I ultimately had it wired to the alternator 5k miles ago and have had no problems. When the engine is on, it runs continuosly.

 

there's no need to wire it to run constantly as the ecu does it already (except when in cold start mode).

 

Hmm didnot know this. See you learn something new everyday.

 

I did too. Sorry for the false info Shardul.

Could have swore the pump only runs when needed in higher temps or under wide open throttle.

So I guess to bleed her, start her on up and get it warmed up.

 

bump, is it an 03 thing for it to run all the time?

I'd like to do this today, but don't want to waste my time if already does.

 

Really?

I ask b/c when the pump is running I can tell by looking into my little fill in tank that I have in front of the engine (water moving around in there from the pump action). When I start the car up in the am, when its cold, I notice that the pump is not on (water not moving around in the tank). After I take it for a drive or when the engine is hot, then the pump comes on (water moving around in the tank). I assumed all of this meant that the ECU is only turning on the pump when its at a certain temp or at WOT. Is that correct?

 

that's exactly what i'm saying. the ecu turns on the pump once the car gets warmed up and from there it's on continuously. unfortunately, i don't know what that temp threshold is...

 

I spliced into this wire:



And grounded the pump, it now runs in key 2 position. Just to confirm, was this the proper wire to splice into?

 

for my slk32 when the rpms reach 2000 the pump kicks on and stays running umtil the car is turned off. most wire the pump to run via a switch so they can circulate the fluid at the track when the car is not running

 

This is not true,the pump only comes on when the blower is engaged.

I can see the temps drop right after I give it enough gas to engage the S/C

early 03 cars ran all the time and MB stopped that since the pumps were dieing fast.

04-06 cars do not run all the time.

 

drove mine around, no noticeable drop in temp

 

ok. thanks!

 

i have mine hard wired, unless you have a big reservoir in the back no need to keep it running at the track. the HE really needs airflow

 

that may be true for later models as i've only tested my '03. however, the problem wasn't even recognized until '06 and to this day mb refuses to admit there was ever a problem with pumps. with that said, i can't see them making the change as early as '04 or '05 and if there was a change in the way the ecu controls the pump, i'd be willing to bet it came out with a software update much later.