98 s70 t5 A/C problem

johnmc70 · Post by **johnmc70** » 30 Jun 2013, 19:15

I have a 98 s70 with an a/c problem. the recirc light and ac off light flash for 20 seconds when I start up. every function on the ecc work except for ac it doesn't kick the compressor on but the compressor works when I took off the relay cover and manually supplied power that way. Anyone have any ideas or wiring diagrams for the ac unit because I really don't want to take it to the dealer

Post by **jblackburn** » 01 Jul 2013, 10:52

Is the air cold when you jump it? Is there refrigerant in the system?

IF there's refrigerant in the system, a pressure switch may be bad.

johnmc70 · Post by **johnmc70** » 01 Jul 2013, 17:16

There is refrigerant in the system and it barely gets cold when I do jump it

Post by **jblackburn** » 01 Jul 2013, 17:24

Jump the low pressure switch with a paper clip and add freon to it. Do not let it pull it below 15 psi. It is on the line at the top right of the engine compartment.

Reconnect the switch when it is holding steady and make sure the compressor will stay running.

johnmc70 · Post by **johnmc70** » 10 Jul 2013, 18:44

ok, so now everything seems good with the ecc, no lights are flashing. I jumped the low pressure switch and made sure I had enough Freon in it and we are good but the compressor and fan don't kick on and when I jump the relay only the compressor kicks on. Where else should I look to next??

Post by **abscate** » 11 Jul 2013, 03:39

You can't do too much more diagnosing without manifold hoses. You could try a used/new low pressure switch. The have a valve under them so you won't lose the refrigerant charge on removal

johnmc70 · Post by **johnmc70** » 13 Jul 2013, 08:30

do you think it could be a bad relay or does it sound more like the low pressure switch? I would hate to buy parts that aren't needed?

Post by **JimBee** » 13 Jul 2013, 11:48

Tracing upstream from the low pressure switch: The system works when you jump the low pressure switch.

The low pressure switch works when you trigger the relay.

But the relay isn't triggering on demand (as set by the ECC dash control). I would grab my multi-meter and determine if I'm getting signal input to the relay (you're getting voltage, b/c it's powering the rest of the system when you manually close it, right?

If you're getting an input signal to the relay, then the relay is strongly suspect. If no signal into relay, then what's next upstream from there?

johnmc70 · Post by **johnmc70** » 14 Jul 2013, 09:38

no the system doesn't work when I jump the low pressure switch and I check the relay and 13v are coming out of 1,2, and 3. Does this sound like a bad relay?

Post by **jblackburn** » 14 Jul 2013, 10:26

johnmc70 wrote:no the system doesn't work when I jump the low pressure switch and I check the relay and 13v are coming out of 1,2, and 3. Does this sound like a bad relay?

What do you mean it doesn't work? The compressor turned on, didn't it?

The fan kicks on when the high pressure side reaches a certain PSI