How to use AIR pump relay for a CSI

Guide for using the AIR pump relay, wiring, and harness for your CSI electric waterpump

I just happened to be doing alot of modifications at once, and was searching on CamaroZ28.com on how to wire up my CSI electric waterpump. I found a post asking the same thing I wanted to know. A member named Buttercup (Thanks!) posted about how he used the existing AIR system wiring and relay for his waterpump, after he ditched the AIR system. As soon as I saw that, I knew that's exactly what I wanted to do, since I was removing the AIR system, as well as installing my CSI, new Opti, etc. Perfect opportunity! I asked him alot of questions about this, and he answered. This is all basically his instructions, but I thought I'd do a page for it.

The following was done on my 1994 Formula, so your application may vary depending on year. I know OBD-II cars will be totally different. This will also work with other brands of electric waterpumps I'm sure, like the Meziere. For tips on the CSI install, click here.

Step1: Solder the AIR pump connector to the waterpump wiring. If you haven't removed the AIR system yet, click here. This connector will make it easy to hook up the waterpump to the rest of the wiring once in the car, to the harness shown. The black wire is negative. The red and orange are both 12V+, I just soldered those two together and to the positive wire on the pump.

Step2: Disconnect the positive terminal on the battery if it hasn't been done yet. Remove the 20 amp fuse in the fusebox for the AIR pump, and replace it with a 15 amp fuse for the CSI electric waterpump.

Step3: Pump activation. We need something to tell the waterpump to activate, stay on, and turn off when needed, so we'll use the signal wire from the PCM to the fuel pump relay.

WARNING Most relays are grounded through the PCM, but the fuel pump relay is fed power through the PCM. Splicing into the fuel pump PCM signal wire with the AIR pump PCM signal wire can result in a short circuit and damage the PCM. Either use the PCM side of the AIR wire as I'll show below, or remove the pin from the PCM.

Unbolt the PCM, and pull it out a bit. You'll notice it has 4 connectors, and each are labeled on the PCM... Blue, Red, Gray, and Black.

The wires we'll be dealing with are all on the RED connector. If you look at the connector, the wires are numbered. The fuel pump relay wire is dark green with a white stripe (DK GRN/WHT) and is pin #7 on the RED connector. The AIR pump relay wire is brown (BRN) and is pin #14 on the RED connector. see schematics I used a neat little splicer for this step, it's that blue thing in the pic. You wrap it around the wire you want to splice into, the green/white fuel pump wire. Then you insert the other wire, in this case the brown AIR pump wire. Just cut it a few inches from the connector, stick it in there, and clamp it shut. Notice on the connector, the other half of the brown wire is stripped and ready, we'll use that in a little bit...

Step4: Reversing polarity. Originally, pin #86 on the AIR pump relay was jumpered to #30, which led to the 20 amp fuse and then to the battery. Pin #87 provided the AIR pump with power when the relay was "switched on", while pin #85 led to the PCM which was the ground. But for our setup, we need to change things a bit. Below you can see the fuse/relay box lifted up, showing the wires underneath... it's a mess!

You need to find the #30 and #86 pin sockets, and the corresponding wires underneath. Both are brown. If I remember right, pin #30 has two wires coming out of it, goes a few inches, and one loops back up to pin #86. That is the wire to snip. The end going to pin #86, the single wire to the relay, I soldered on more wire to lenghthen it, and grounded it under a bolt on the chassis, it's the yellow wire shown.

The other end, from pin #30 with both wires, one going back up to the AIR pump fuse, is where we'll add the resistor...

Step5: Tricking the PCM. Now, it's either time to use that brown AIR pump wire at the PCM from Step #3, or remove/tape it off. You can use a resistor to trick the PCM into thinking you still have an AIR pump. And if the waterpump fuse blows, this should activate the SES light. I got out some wire and soldered it to the brown AIR pump wire, then routed it up to the front and over to the fuse box. Used some zip ties, and followed the factory wiring pretty much. You can see in this pic, it's the yellow wire snaked through there.

Now that we have run our wire to the fuse box, we can put in that resistor, and connect it to the wire going to pin #30. We measured the resistance of the AIR pump system, and decided on a 100 ohm 10 watt resistor to fool the PCM. Part # 271-135 at Radio Shack, they come in a pack of 2 for $1.69. Just solder it inbetween the last two wires, and that's it. I tucked the resistor up under fuse box, and zip tied the wires in some spots to keep wires from hanging all over.

That's it, you're done!

SCHEMATICS

AIR PUMP REMOVAL

To make the above project work, you need to remove the AIR system. This is fairly easy. The AIR system consists of an electric pump, pipes that direct the air to each manifold, and a rubber hose that feeds the air from the airbox to the pump.

I think 3 bolts hold the pump and bracket in place, I forget, but easy to remove. The rubber hose is easy to remove, but you'll need to find something to plug the hole in the airbox or CAI, some sort of cap. The metal piping that is routed to each manifold can be tough to remove, mainly the passenger side. I had to chop my pipe up with a Dremel. Plugging the AIR fittings left from this can be difficult, or sort of expensive in my case. Or maybe you have headers without the AIR fittings. After searching and searching for a cheap solution, I caved in and bought the M22 drain plugs from NAPA... I think they cost around $8 each. Later cars have a different size bolt, 96+ use 3/4-16" bolts I think. 93-95 use 22mm bolts.

So after you have removed the AIR system, you'll have much better plug access! And you'll have a free relay and wiring harness to work with. Speaking of harness, try to get as much of it as possible from your AIR pump. I smashed mine up and broke it apart... so I could get more wire to work with.You can also preserve your pump for later and leave it intact, heck, you don't even have to use the harness. But I think it's pretty nifty though.

CSI TIPS

You need to remove the mechanical part of the pump to install the CSI. Instructions said to use a punch on the shaft I think, but I got tired of pounding on it, and took it to a local parts store with a machine shop in the back. The guy put the pump on a press, and popped it right out, cost only a few bucks.

You need to grind in 4 notches for the CSI, so I took some pics to show how much and where. I used a Dremel for most of it, but it wore out the grinding stone pretty quick... I might have been using the wrong one. I used a rounded file for the rest, and just kept grinding it down, test fitting, grinding, etc. It wasn't too hard, and worth it considering the price, compared to the easier Meziere which requires no grinding.

I spray painted the waterpump housing with a high temp engine paint. I wanted a dark red color to match the car, but the selection of colors was limited. So it's Chevy Red. Just tape off the gasket surfaces and plumbing, then spray it. I think it looks nice, and makes repairs a little bit more fun.

Guide for waterpump install