02 Jetta (auto) No AC

[Steve777]

I have not been driving this Jetta much, and was yesterday and to my surprise no AC. It worked the last time I drove the car in the summer (probably last year).

So when I got home did some quick diag work: Blend door was working (air got much hotter when temp switched to hot). Rad fans work, heard and saw them come on when waiting at lights, although maybe not at high speed. Hard to say since I rarely hear/see them in use. When the AC dash button is pressed in, the light comes on, which I think means the fuse is OK. With the vent fan on and AC button on, the compressor clutch is NOT engaged (turning), and neither rad fan comes on???

In checking various posts, I thought it might be the infamous 384 relay, so I pulled the lower dash panel and took a look at the relays. I did not see any 384 relay under there???

So, I guess my questions are:

Which is the AC relay and where did they hide it?

And besides the relay is there any other diagnostics I can do without a set of AC gauges?

 

[mxracer291]

The radiator fans should come on when the button AC light is on. Search mk4 AC diagnosis I know I saw a whole post about this once upon a time.

also some good info here https://forums.tdiclub.com/showthread.php?t=245942

 

[1854sailor]

Your car does not have an 384 relay. That's a B5.5 issue.

Did you check the 30A fuse in the box on top of the battery? I had the same problem with our '01 Golf and it was that fuse. The fuse had not blown, but the contacts looked like they had overheated. I pulled the fuse, cleaned the contacts and closed them up a bit, cleaned the spades on the fuse and put it back together. Problem solved. I have since seen and fixed this same problem on 2 other cars.

Several threads on here about the same problem.

Please report back.

 

[casioqv]

There is no point in hooking up gauges, unless you don't get cooling with the clutch engaged.

 

[whitedog]

There is no point in hooking up gauges, unless you don't get cooling with the clutch engaged.

I think that is close to right. If the fans come on and the clutch doesn't engage, then the charge could be low or zero, so in that case, the gauges are needed to verify sufficient charge. But if the fans aren't coming on, that is a fan control issue and if the fans don't come on, the clutch won't engage.

Check DanG144s guide to troubleshooting the fan system first.

 

[CoolAirVw]

Check the small fuse furthest to YOUR left in the row of 3 in the fuse box on top of the battery. It tends to "meltdown" lots., So pull it out and visually inspect for damage.

Also the clutch coil fails frequently