rear heater.

What is this part called, and can it be generic? Best place to buy it?
The rear heat doesn't work in my '97 van. The blower is fine.
I've traced it down to an electric powered vacuum valve that controls the water valve to the rear heater.
By memory, it's about 50mm long, silver metal with a 12 volt connector (2 wires) at 1 end, and black plastic with 2 vacuum lines on the other. It's located in the engine bay, near the engine, on the passenger side.
It's got 12 volts when heat is asked for,(0 when off), and has a vacuum at 1 line. If I put a vacuum on the other line, I get heat.
So what is it?
Thanks

It's your vacuum actuated water valve control solenoid for the rear heater- makes sure it has vacuum supplied to it. Is this an OEM factory installed system or has your van been upfiitted by a van conversion company?-- they can be designed differently depending on the upfitter.

I'd check for vacuum leaks in the vacuum supply line. and then check to see if the solenoid allows the vacuum to transfer to the output line that goes to the rear heater valve. Sounds like this vacuum solenoid (or vacuum switch) is inop...

If the rear unit is factory equipment, the AC Delco part # is 15-5551

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1371215&parttype=6859&a=FRc1371215k84593 (wait for the entire page to load and it will show you the part.)

If the rear unit is an aftermarket unit, you'll need to go directly to the manufacturer of the unit.

Hi Old Master. Thanks for the link.
It is factory rear heat. That's not the piece though. And there is vacuum on 1 side, and 12 volts when switched on.
The water valve works fine, if I put vacuum on it. It's the electric controller of the vacuum i need. It looks like the top part of # 15-5877, that half metal, half black plastic thing. Mine is a separate piece from the water valve. It looks like they would want to sell me the whole thing.
I'm tempted to put an aquarium air valve in there, on in winter, off in summer, and let the blower do the rest.
http://www.rockauto.com/catalog/raframecatalog.php?carcode=1371215&parttype=6859&a=FRc1371215k84593

Here is a link to the AC Delco site. Enter your vehicle information and select Heating/AC then Heater core and htr control Vlv. It will show all possibilities of water valves used on your '97 van. If your part is not listed, you probably have an aftermarket rear unit.

http://parts-catalog.acdelco.com/b2c/catalog_search.php

Another interesting web site.
I bought the van used, but it sure looks factory.
I'll get my VIN and have a search
Thanks for your help.

You don't need the VIN, you can just enter year, make, model and it will list the parts.

And yes, some of the aftermarket stuff looks like OEM making it difficult to tell the difference unless you know exactly what to look for.