Auxillary water pump for turbo

[dds28]

Recently my water pump for the turbo stopped working. How do you test the relay (951 618 149 00) to see if it is good? It doesn't look like other 5 pin relays. I think it's because of the timer built into it.

[blueline]

Recently my water pump for the turbo stopped working. How do you test the relay (951 618 149 00) to see if it is good? It doesn't look like other 5 pin relays. I think it's because of the timer built into it.

I haven't the answer but will give your post a bump in the hope that someone (@Tom ?) can offer advice.

[dds28]

Thank you!

[Tom]

Sorry, missed this the first time around, so appreciate Tim bumping it . I'm always up for a 951 question. Pin 30 supplies battery voltage to the relay; the thermo-switch on the turbo coolant pipe connects to pin TS (center pin) and pin 87 supplies voltage to the water pump when the timer is running. When the thermo-switch temp exceeds its switch point, it simply connect its wire to ground (via the grounded sensor body) which in turn grounds the center pin on the relay and as a result switches power to pin 87/pump for ~30 seconds.

I made this video showing how to bench test it, but I also confirmed if you just pull the wire off the thermo-switch and ground it, the pump will go on for 30 seconds or so. If nothing happens when you ground the thermo-switch wire, it could be either the relay or the pump. You can check check to see if the relay is trying to deliver power by pulling the one-wire connector off the aux pump and checking for battery voltage on the non-pump side of that connector right after grounding the thermo-switch. That pump wire is connected directly to 87 on the relay, so checking it for power after grounding the thermo-switch is the in-situ equivalent of the test I'm doing in the video.

[blueline]

Tom, your video is marked as private. Is that on your end?

[Tom]

I made a change to it after initially posting it, so wonder if you clicked while the video was in limbo. Can you check again?

I think I confused youtube with the edit. I just updated. Should work now. Right?

[dds28]

Tom,

Thank you for the video. I will check my relay again and report my findings.

David

[blueline]

I made a change to it after initially posting it, so wonder if you clicked while the video was in limbo. Can you check again?

I think I confused youtube with the edit. I just updated. Should work now. Right?

Yes. It's good!

[dds28]

I just tested my relay. I couldn't reproduce what Tom showed on the video. I think the relay is bad. I got no readings at all. No clicking sound either.

[Tom]

I just tested my relay. I couldn't reproduce what Tom showed on the video. I think the relay is bad. I got no readings at all. No clicking sound either.

If my math is right, you could also pull the relay out and jumper the socket by applying 12 volts to terminal 87, just to confirm the pump and that side of the harness is working too. However, if you faithfully replicated my video test and didn't get power on terminal 87, that's pretty conclusive proof of a bum relay....

If you are posting elsewhere about this, feel free to link that video. I made it after googling and realizing there wasn't much out there on how exactly that relay works... We're all about going the extra mile here on Carpokes.