It has been discussed in different threads about when the I/C pump runs, I for one had started a thread called "Pulse Voltage" it was a term in the SRT 6 repair manual. I had finally called RENNtech and they said if the key is in the on position the I/C pump is running and a few other members had agreed that it was a true statement. Well yesterday I hooked up a meter to the pump and placed it where I could see it from the drivers seat. I turned the key to the on position, no voltage was displayed on the meter. Then I started the car - still no voltage, I slowly depressed the gas pedal all the way to max RPM while in park (around 3,800 RPM), still no voltage. I then shut the car off then started it back up and started revving the engine, starting out slow and kept revving more aggressively each time. The meter finally displayed 14.xx volts if you nailed the gas pedal fast and the voltage stayed on even when just ideling, I shut the car off and turned the key back to the on position - no voltage. So basiclly when certain conditions are met a relay latches for the pump control module and the pump stay's on as long as the car is running. I hooked up the meter to fuse #13 and done the same thing that I had done with it connected to the pump and got the same results, I believe this fuse is the last component in the I/C pump circuit. I went ahead & ran a couple wire's into the car to an LED I mounted by my HE temp gauge so that I would know when the pump came on. Wondering if the supercharger had anything to do with one of the conditions that needed to be met for the pump to come on, I pulled the connector off the S/C clutch and inserted a couple solid small gauge wire's then plugged the connector back in. I connected a LED to these wires to tell me when the S/C engauged and started this process over again, the pump came on, but the LED connected to the S/C never did. Being concerned that I did not have a good connection with the wire's stuck in the S/C connector, I had the wife come out to operate the gas pedal while I took the meter leads & periced them into the S/C clucth wire's. I had her slowly rev the engine and each time rev it more aggressively, the pump light finally did come on, but I never did get any voltage to the S/C clutch. I then had her rev the car slowly up to around 2,500 RPM - hold it for about 5 seconds then go ahead and nail it while I still had the leads stuck into the S/C clutch wire's. I got the crap scared out of me, I never did get any voltage on the meter, but at the top end of her nailing it hard the clutch did engauge for a split second and let out a BIG CHIRP. I don't know for sure, but I'm guessing some how my meter caused this split second of the S/C clutch engauging. I don't think the S/C has anything to do with the conditions that must be met for the I/C pump to come on. Now that know that the pump does not run with just the key on, I will be running a second circuit isolated from the OEM circuit to the I/C pump using a relay operated by my remote control HE fan circuit. This will let the coolant circulate and be cooled by the HE fans while the car is shut down, thus helping with the heat soak issues.

 

I found similar results on the pump. When I changed mine I used a test light to see when it was on.
It does not run just because the key is on that is for sure and it also does not continue to run when the key is shut off as reported. (at least under all conditions)

 

Nice test Steve, i was under the impression the s/c clutch only engauges in drive. Have you driven on the road yet to confirm when it engauges?

 

I think you are right about the S/C, I didn't run a wire in the car for a S/C clutch for a light. My car is still sitting on my car hauler trailer when I done all of this and still is, I was just trying to see if the S/C clutch had anything to do with conditions that needed to be met for the I/C pump to turn on. I just wanted mainly to see if the I/C pump wood run with just the key on after shutting the car off after the pump was running. I'm heading to town now to get some parts to build a circuit to get the pump to run anytime my fans are on.

 

Great test Steve! - The only variable left to discover is how the pump reacts (and you have the LED and a IC coolant gauge to observe) - when the IC coolant is warm/hot or at some pre-set temperature. You might need to take it out and run that SRT hard.

I thought when my car was sitting on the dyno between runs (hot hot hot) and they left key in the "ON" position - I squeezed one of the IC hoses and felt the coolant flowing. With your test - the engine running at high rev's and cold IAT's - the relay may have signaled the IC Pump on in anticipation of what's to come...

Thanks for the heads up PM - I am pulling the front bumper today to install the Johnson pump and do a slightly different mod to the HE. - But the phone just rang and a part I ordered for my motorcycle is in - so a quick detour before I start.

 

I finished confirming that the connector hot wire at the pump is one side of fuse #13 & the ground at the connector is grounded at all times. So whipping up a seperate circuit is a peice of cake. Using a small power relay you would just pull #13 fuse - run a wire from the side that is hot when the pump should be running to terminal #87a of the relay. The other side of where the fuse was,(goes to pump connector) you would connect an in line fuse holder and run it to terminal #30. Then for the aux. power, use one of the hot studs at the fire wall end of the fuse box and run a perferably fused wire to terminal #87. Then for the coil of the relay, ground terminal #85 and use a 12 volt source (toggle switch or ???) to terminal #86 to change from OEM circuit to AUX. circuit. All of this can easily be hidden under the top of the fuse panel. My relay will be operated by the remote control for the HE fans and I will have a small green LED inside the car that will be connected to terminal #30 that will tell me the pump is running. With having the the other small blue LED connected to the remote control fan relay, I'll even be able to tell witch circuit the pump is running off of .

 

Nice to know this for sure, I figured that's the way it worked. I upgraded to the johnson pump a while back and wired a seperate circuit controlled by a switch. I think your fans are a great idea and I might need to invest in some once the 90+ temps hit here in Louisiana.

 

Sunday, (yesterday) I used a SPDT power relay to install an aux. circuit for the I/C pump and done as I stated in the 6th post on this thread. The nice thing about the way it is set up is that I can shut down the engine, leave the key off and turn on the fans and pump from a small key fob. The fans were already connected to a fused constant 12 volt source so I hooked up a fused constant 12 volt source for the aux. pump circuit. The pump aux. circuit relay is turn on by the remote control fan relay with a little green LED mounted on my HE temp gauge to let me know the pump is running. So this sould help cool down the I/C coolant while circulating it with the fans sucking 660 cfm of air through the HE between runs at a track by shutting the car down and clicking the little key fob. That is if I ever make it to a track.

 

Hmm... I'd be curious if the ECU doesn't allow the SC clutch on unless you are actually moving under a load... hmm... where are those test leads I had laying around...

 

After looking over the drawings in the tech manual yesterday, I think that the S/C clutch is in series with another component. Not just a ground & hot wire to the clutch. But I'm pretty sure that the S/C will not engauge in park, unless you have meter probe's stuck into both wire's . When the wife nailed it hard while I had the meter across the clutch wire's, it let out a big chirp and scared the crap out of me .

 

Steve,

Please let me know how this works out. I'm very interested on doing this to my car. The mod, that is, not scaring the crap out of you....

 

If it ever quits raining and gets warm around here, the car is still on the car hauler in the garage. I had it out a few weeks ago when it was warm to check out the new fans & HE temp gauge for the first time. When I pulled in the drive to park the car I turned the fans on, the HE temp was 133 and dropped to 124 in five minutes while idling. But I think I might have shut the car off and turned it back on, so it's possable the I/C pump wasn't running all the time. Now that I will be able to tell when the I/C pump is running the results may be better. I figured I'd post a few pic's of the LED's that comes on when the fans & I/C pump is running. The pic with the HE gauge on with the green LED is of the car running and the pump is on the OEM circuit. The one with the HE temp gauge on with the green & red LED on, the car is running and the I/C pump is on the Aux. power. All the pic's with the HE gauge off and the LED's on is with the car shut off & the key off. The green LED is the I/C pump & the red one is the fans.

 

Man, I wish they would have put an indicator on the dash for both the IC pump and the SC. That is a great idea. If I get ambitious enough, I just might wire something up. Thanks for the good info Steve!

 

Wiring up a light to the OEM I/C pump is pretty easy, just add one of those little things that slides over the fuse blades (#13) that has a male spade connector. Insert the fuse back in & run a wire from the spade inside the car then find somewhere under the dash for a ground. That's what I done before I built the aux. circuit to get the pump to come on when I turn the HE fans on. When I done what's posted in this thread the car was on my trailer sitting in the garage. I already had the HE temp gauge & fan light wire's ran into the car, when I done them I had the whole bottom of the dash out and they were tie-wrapped up to things. But when I ran the wire for the pump light I just threaded it into the firewall with the rest of the wires and just dropped the dash low enough to fish the wire to the temp gauge. I figured the wire would just lay on the bottom of the dash with no problems, WRONG. I pulled the car off the trailer Wed. and when I went to put the car back in the garage I was turning the steering wheel then I felt some resistance then it went away . I kind of had an idea what happened, I turned on the fans and had no pump light. Talk about luck, when I fished the I/C pump light wire in, the wire went right through the "U" joint yoke of the steering shaft. If a person was tring to do that, it would never happen. I dropped the whole dash out yesterday and re-ran the wire with the rest of them with tie-wraps like I should have done in the first place.

 

Just so I can be sure I understand how you wired it up, let me repeat it and see if you agree:

You wired an LED poistive lead to one of the blades on the #13 fuse and the negative LED lead to ground, and it lights whenever the IC pump engages. Right?

I don't suppose there is a similar fuse that could be done to for the supercharger? All I want is an indicator, I don't need the extra switching you're doing.

 

On the fuse #13 right and since an LED does not draw hardly any current you could use a very small gauge wire, strip about a 1/2" of insulation off, pull the fuse, put the wire directly under the fuse blade and put the fuse back in. Either side of the fuse will work, but it would be best on the side that goes out to the pump. If I remember correctly it's the one toward the middle, but if you have a meter pull fuse #14, turn the key to the on position and see witch side of where the fuse plugs in has 12 volts. You could do the same with #13, but you would need to get your pump control module to turn on first then put the wire on the side with no power. As far as the supercharger goes I've not confirmed that the two wires going to the clutch are + & -, looking at the drawing in the tech manual the clutch appears to be in series with another component. I've not found a fuse just for the supercharger yet, but I have not had the time to look hard for one.

 

Thanks Steve!

 

When I was trying to find a supercharger clutch fuse in the tech manual I was at home and my computer kept locking up on me. But I'm at work now and have been doing a little looking at the tech manual, the supercharger clutch does not have a designated fuse. It does have a fuse but it is built into the Relay Control Module (page 2583 of the tech manual), when the key is turned on it activates the Engine Control Relay and sends 12 volts to the clutch. The clutch is sitting there waiting for a ground in the Powertrain Control Module and it will not recieve the ground until certain conditions are met. So basiclly if you connected a small LED to pin #2 on the clutch connector as shown on the same page (2583) the light would be on any time the key was on, but I think if you connected a small LED to pin#1 wire, it would only light up when the clutch is engauged. If you really want to do this, you might PM MMZ_TimeLord or (he may read this and jump in) to make sure it would not harm anything. He has better GRAY MATTER than me .

 

I finally got my car out yesterday to see when the pump LED comes on under normal conditions. I started the car, let it warm up a couple minutes and drove slowly out the drive. I turned out onto the road slowly and still had no pump LED on, but as soon as I gave it enough pedal for the S/C to kick on the pump LED came on. I kind of thought thats how it would turn out, but after shutting the car off then just turning the key to the on position the pump does not run.

 

Steve - this is probably one of the best discoveries yet!!

Now you need to wire the IC Pump to a relay and remote fob like you did for your fans. (I think I might just do this) It might be more effective then installing a larger HE.

I would think having the IC coolant flowing through the HE while the fans were running would get you the best results.