98 Suburban A/C not working

[jrsavoie]

The little light comes on but the clutch does not engage.

Pulled and checked both plugs off the pump for voltage. Had at most .07 on any wire.

Changed the relay and tested fuses.

What's next?

Thanks

 

[THEFERMANATOR]

Are you sure it is charged? If so I would jump the low pressure switch and see if it comes on(switch on the silver canister by the firewall).

 

[jrsavoie]

I have no gauges so I have now way to tell if it's charged. Would it hurt to jump it just to check?

 

[THEFERMANATOR]

I have no gauges so I have now way to tell if it's charged. Would it hurt to jump it just to check?

Without having guages or knowing if it is charged, I wouldn't let it run for more than a few seconds by jumping it.

 

[OrionThade]

manifold gauge set is $50 at harbor freight ...

 

[jrsavoie]

manifold gauge set is $50 at harbor freight ...

I had some once. Didn't sell them or give them away.

 

[jrsavoie]

Without having guages or knowing if it is charged, I wouldn't let it run for more than a few seconds by jumping it.

I just touched the plug with the jumper wire and it kicked in. Guessing we have a leak.

 

[THEFERMANATOR]

I just touched the plug with the jumper wire and it kicked in. Guessing we have a leak.

Or a bad low pressure switch. They aren't very expensive and fail often. It's cheaper to put a new switch in than it is to buy a set of guages. If you do have a leak though, the common leak point is teh high pressure schrader valve where the guages hook up.

 

[WarWagon]

You are at the point you need to borrow the tools to do the job or take it to the shop for a diagnosis. Myself I would be careful with the low pressure switch as the valve in the accumulator can leak. The second the o-ring comes off the switch you can't screw it back on with it still leaking. By the time you get to a shop the system will be empty.

Minimum tools are the gauges and leak detector. Vac pump can be rented.

Don't use the high side valve unless you have to. And then expect to replace it as debris from the compressor will make it leak or heat and age ruined the seal so it will not reseal.

Some shops will credit you for 134A recovered. So a diagnosis and recovering the system can be worth the money. You change the parts at home, suck it down and recharge it. Again a leak detector is very useful to make sure repairs are good.

 

[jrsavoie]

I've always wanted to take a class on automotive AC. Maybe one of these years