Tn75s air conditioning relay

[LouNY]

Again with the tractor running I opened both manifold valves and the low side went to 175 and the Red High side dropped to 190.

Never open both valves on a charged system.

OK, step one.
all the gauge set ups I have used when checking your pressure the manifold valves are CLOSED.
With the valves closed the lines feed to the gauge but not into the manifold.

With the tractor shut off, connect your gauges to the correct fittings on the system leave the manifold valves closed, at this time you should have the same pressure indication on each gauge, this is your static pressure.

Start the engine and turn on the AC DO NOT OPEN the manifold valves, now you are reading the operating system pressures.

The ONLY time you should open the manifold valve(s) are when adding freon or pulling a vacuum on the system.

When adding Freon only open the LOW side valve to draw from your source into the low side of the system.

The only time to open the HIGH side valve is when evacuating the system or when pulling the vacuum.

Here is a link to a U tube video on using the gauges and manifold, I did not watch the entire video but it seems to explain the proper use of the gauges and manifold.

 

[jammer48]

Never open both valves on a charged system.

OK, step one.
all the gauge set ups I have used when checking your pressure the manifold valves are CLOSED.
With the valves closed the lines feed to the gauge but not into the manifold.

With the tractor shut off, connect your gauges to the correct fittings on the system leave the manifold valves closed, at this time you should have the same pressure indication on each gauge, this is your static pressure.

Start the engine and turn on the AC DO NOT OPEN the manifold valves, now you are reading the operating system pressures.

The ONLY time you should open the manifold valve(s) are when adding freon or pulling a vacuum on the system.

When adding Freon only open the LOW side valve to draw from your source into the low side of the system.

The only time to open the HIGH side valve is when evacuating the system or when pulling the vacuum.

Here is a link to a U tube video on using the gauges and manifold, I did not watch the entire video but it seems to explain the proper use of the gauges and manifold.

Wow Lou Thank you! I will get to this in the next day or two and report back... I am feeling a bit under the weather. I am determined to get this right.

 

[nyone]

I put freon in and touching the evaporator I had cold going in to touch and warm to touch coming out

It sounds like the system is working. Maybe not working well but working. Are you sure the evaporator and condensor are clean and clear? Can you see light through them?

 

[5030]

Everyone that's willing to learn or do things them self is in over there head at some point. It's how you get out of it. If your going to smack every project with your check book you will never learn anything.

OP AC in this and vehicles arnt very hard to work on. We just need a few key questions awnsered.

Over your head with an ac system can result in very expensive component replacement. Usually leaks can be attrobuted to charge valves not seating properly.

 

[nyone]

Over your head with an ac system can result in very expensive component replacement. Usually leaks can be attrobuted to charge valves not seating properly.

I have also had compressor seals leak and condensers have holes that where 2 weeks old. In fact I replaced the condensor 3x on one vehicle in 1yr. Finaly figured put that out of the box they had multiple pin holes. Could be a million reasons for a leak.

I have a leaking service port on a vehicle I'm driving right now. The cap holds pre pressure all year.

 

[5030]

...and for some reason AC techs fail to replace the caps when servicing them. Sort of like valve caps on tires....

 

[jammer48]

It sounds like the system is working. Maybe not working well but working. Are you sure the evaporator and condensor are clean and clear? Can you see light through them?

No both are extremely dirty... I am working with basicly one arm... shoulder surgery
in 10 days... trying to get this all done before surgery.

 

[5030]

You will find that the cost of relay's at your dealer will most likely be 4-5 times the cost from an electrinics supply place like Digikey or Dell Electronics. Not Dell computers FYI. My relays were 85 bucks per from the dealer and I crossed the catalog number at Digikey and got the same exact relays for 8 bucks each. I bought a few extra, just in case.

Pays to shop around on some stuff.