I asked a question about the A/C not working the other day. I received some excellent advice and it appears that it is either a failed DCCV or a short in the harness [that was the problem last time I repaired it 4 years ago]. To get a look at both problems requires the same amount of prep work so I thought I would order an new DCCV just in case.

My question is - there seems to be a number of manufactures of this particular valve and the price varies from $45 to $200. Is there a preferred brand? Rock Auto offers a couple of brands but the Gates Corporation seems to have the most extensive spec sheet and offers a limited lifetime warranty for under $100. Other manufactures include Four Seasons, Ultra Power, SKP, Bosch etc. It a bit of a PITA to replace this valve and I'd like to avoid an inferior product that will fail quickly. I understand that these units tend to have a short lifespan.

Is it possible or advisable to bench test the unit before installing it? I have other vehicles to drive/ride and with the current situation in the Detroit area I am in no hurry.

Also, my memory fails me but it seems with my previous fix of the system I was never able to shut off the HVAC system from the control knob on the dash [turned out to be a short in the harness but I replaced the DCCV, upgraded the CCM and replaced interior and exterior sensors. Currently it blows cold until the engine warms up then I get full hot on driver's side and reduced heat on the passenger's side - I can shut off al heat by turning off/pressing the control knob on the dash.



Thanks for all the help

 

Hello,

I bought a gates dccv from Rockauto. For me it can be a chinese dccv. The OE part comes from Bosch and it's made in France (engraved on the top of the part). That Bosch part is known to fail and to leak, so imo the brand doesn't matter so much. Just buy one with a warranty just in case.

I've just seen that the gates part has a lifetime warranty. You should buy the Gates.
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I ended up buying the Gates from Rockauto. The current one in the vehicle is a Bosch - which I replaced 4 years ago which replaced a Bosch which the previous owner replaced 4 years prior to that - don't know the history before that. Looks like they fail around every 4 years regardless of the mileage. I liked the fact that the Gates has a lifetime warranty - looks like a US company hut the part is stamped made in China - really makes no difference where it is made to me, just looking for a quality replacement part.
I got it out yesterday [ PITA - buat I've done it before so I knew a few tricks] and then dropped the retaining bolt from above when I attempted to install the new unit - heard it bounce twice in the engine compartment - can't find it anywhere. I am going to replace it with a standard size 6mm x 30mm with a flange 10mm head as that is all I can find at the moment.

 

A bench test won't hurt, but won't give a definitive answer to confirm a DCCV is good. It can weed out some (but not all) faults.

I think the most common fault is coolant leaking into the electrical side and shorting it out. This would be very unwieldy to test on the bench.

Another common fault is crud collecting in the coolant passages, and restricting valve motion. This one is a crapshoot, with no way to test for it.

For electrical tests, some data is here:

https://jaguarclimatecontrol.com/dia...test-procedure


Those are in situ tests, so you'd have to extrapolate for a bench test. Each coil draws about 0.6-0.9 amps. You could rig up a FUSED power supply and ammeter to test each side. Power to the center pin, ground on an outer pin for each side. You should hear the valve click and might be able to see movement inside one of the tubes.

With an ohmmeter, you can test continuity of each coil. Not sure of the exact numbers, but probably 10-20 ohms on each side. Whatever the numbers, the two sides should be fairly close.