LaoBron

Pump won’t turn on unless I fiddle with the fuse box.

I checked pump relay it’s good
check pump itself and it’s good
cleaned the connection at the pump and relay
Took fuse box out and cleaned that too

After the cleaning of the fuse box it started working again for about 3-4 starts then after that it stop and I would have to open the hood to slap the fuse box then it would turn on. I’ve searched the forums and people were changing out some clips on the fuse box but I don’t know what?

captain vette

How do you know the pump is not working one can’t hear it from the cockpit, just curious if it ever happens to me

SIK02SS

The problem is almost guaranteed in the fuse box. I literally had this exact problem and tried quite literally everything, including tearing my fuse box apart to find a problem and replacing it. The problem for me and a couple others I've spoke to is in the connector that plugs into the BOTTOM (underside) of the fuse box. I have spoke to a couple people that the copper links inside had some how shorted/broke a connection joint, so that is a possibility too. But check the under side of the fuse box, I didn't look close enough when inspecting mine (wasn't looking for that to be honest) but there is light electrical scoring where that plug goes into the bottom of the fuse box. I'll try to upload a pic for you later. The fix was a replacement plug

SIK02SS

You can squeeze your hand in and feel it. It's not hot, just get your hand down there and touch it and you'll feel it working or not working. You can also feel the coolant lines, but it's not as good as feedback from all the engine vibration. Or get a dashlogic to be able to see your IAT2 temps. If they are on average higher than 20-30 degrees over ambient (on a hot day) or creep up to 160+ with standard driving, then it's most likely not working or you have other problems like a leaking brick

LaoBron

Yes the connector replacement is what I’ve been hearing about but never knew what it looks like. I have a dashlogic that reads my IAT2 so that’s how I know it’s working and I also feel the hoses and water pump itself.

When you say check the fuse box it’s not that copper grid line that I’ve seen right? Where you have to break those 4 metal washer out and then take it apart some more

SIK02SS

When you unbolt/unplug/remove the fuse box as a whole, it'll be a large grey (iirc) plug on the side closest to the firewall. I just checked my old fuse box, the scarring from the arc (bad connection) was on the actual surface of the plug itself, not the pin on bottom of the box. So remove the box and inspect the plug face for any scarring from an arc. To be honest I didn't find this, my local dealer finally got their really good corvette tech back and he found the problem but he showed me everything and the fix was actually less than $100 for me. The rest of that service dept is useless and so was his short lived replacement.

Yes, some people have had issues with the copper grid having a break in it. I don't know if they attempted to re-solder the broken joint or just replaced the box, but after you break the box apart, it doesn't hold back to together very well and if it were me I'd just replace it (which is what I did after I cracked mine open).

LaoBron

LaoBron

I used crc electronic cleaners on the pins and dielectric grease

LaoBron

So I got the pump to turn on and off while the car is on by tugging and pushing this bunch of cables gently.

SweetZO6

I don’t have any electrical issues on my ZR1 but it is 10 years and this post made me pull my under hood fuse/relay panel apart. Took an hour. Fairly easy job. Good preventative maintenance. I found no corrosion or signs of arcing or bad connections. I did find the power plug wires showed some mild rubbing and that was corrected by repositioning those wires. Also applied CRC dielectric grease to the connector faces. It sure went back together easier. Also, I swapped the relays and greased as required. I do the same to the passenger floor fuse panel. Doing that every 6 months is a good preventative maintenance thing.

Ed

LaoBron

Was able to take apart the fuse box
you guys see something I’m missing?

chassed

I had this issue as well.

replaced the fuse box it worked. Then it stopped working again.

ended up being the harness so we hard wired it bypassing the harness.

LaoBron

where did you end taking the power cable? So it just comes on every time you start the car?

LaoBron

I tested the fuse box with my multimeter going through every one of the connections and got all good readings. So I just closed it back up. Start the car and it works.

I take it for a spin to the store. I started her up for the ride home and my whole car dies dead no lights can’t get out. I pull the lever and got to the trunk to check terminal and it was loose. As I reached to tighten the negative cable ther car lights came back on. I tightened it and everything since then has been working just fine pump and all. I took out for 2 straight days and it works every time now.

so this whole time it might have been just a loose negative terminal. I did add the battery tender cable to both positive and negative terminal and maybe that’s why it wasn’t tighten all the way because the nut cone was screwing into the battery tender cable. I took that cable off and placed it on top now with a M6 wing nut.

all is well now I’ll report back if it stops again

Itbites

My ZR1 wouldn't turn on the CAC pump. Same symptoms as several others. I finally traced the problem to the fuse box, as others have as well. My copper traces were fine. For me, the solution was to 'tweak' the correct terminal in the gray bundle connector at the very bottom level of the fuse box that is shown in an earlier photo in this thread. I tweaked the spring-contact terminal to have better retention in its location as well as to have stronger contact force with the blade inserted from the level above. I basically bent a few of the 'spring-load' features of the terminal for better connection. No recurring issues. I can state that the contact at the blade to terminal connection showed some conductivity when using a DVM to measure the circuit (15-25 Ohms usually and it should be close to zero), which misled me for days. The connection would not, however, pass even the low current needed to pull in the relay, so it drove me crazy. Anyhow, just one more vote for checking the lower levels of the fusebox, if your CAC pump is not turning on.

LaoBron

thanks I ended up swapping out the fuse box and all is well since then. I was able to get a new one for $225 so that wasn’t too bad came with all new fuses too

Gum1993

Reviving this thread. I'm thinking of hardwiring my coolant pump and was wondering where and how this was done.