The A/C in my 98 RR 4.0SE still works off and on and the restart still works, but I have interest in IDing the system relays functions.

RL-6 and RL-7 show a large fan icon for auxiliary power, what does each relay control, and if it's bad what fails to work?

RL-13 and RL-14 shows a large snowflake for AC condenser fans. If either relay is bad, what does not work?

RL-18 also has a large snowflake, and says A\C control. How does it control the AC.

Sorry for three question, but for my AC to come and go like it has for almost a year, I'm thinking maybe a bad relay or a failing relay that works until it gets warm and cuts off.

I'm ordering three yellow relays just to keep on hand, just in case.

 

BY the way,neither condenser fans are working. I tested them both to 12V and they both ran great.

 

My yellow Relays should arrive tomorrow, should I disconnect the battery before changing the fans and AC control relays, or does it matter?

Thanks

 

The blower motor relays give additional power to the blower motor fans, they will still work without the relays, but it will not blow hard. they usually smoke due to dirty pollen filters causing the motors to work extra hard. The condenser fans wont come on until the ac high side pressure is north of 400 PSI (hardly ever)

 

Is all the Green Relays the same relay, but given different duties to perform in different slots?

Are all the Yellow relays the same way too?

Thanks

 

check your fuse box under the #6 or #7 relay, I bet you will find signs of over heating. common p-38 problem

 

Today I replaced three yellow relays, RL-6 RL-7 and RL-18. And replaced two green relays, RL-13 and RL-14.

I inspected the fuse panel closely and it appears to be in good condition without any burnt spots or burnt relays.

But no improvement in the AC system. I still have AC working on most 5 minute restarts.

I'm still digging for information and a cure.

Any and all suggestions are welcome.

 

Too complicated for you to diagnose. Could be: Low system pressure, Bad outside temp sensor, Bad evaporator temp sensor, Bad trinary switch, bad low pressure switch, low freeon, bat temp control head. You get what I mean.

 

I changed the outside temp sensor, the one inside the airduct last year, so we can forget that item. The old sensor said it was 52 degrees when it was really 90 degrees. The A/C control screen now displays the correct fresh air flow temp.

But I'm willing to go as far as it takes, to first understand the system, diagnose the problem, and to try to repair the A/C issue without dropping the RR off at the Dealer.

Everyone else at this forum is either looking for help with their Range Rover or is here to actually help someone resolve a problem with their Range Rover.

What would the next step be? One down ten to go?

 

I'm not giving up yet...

This weekend I'm picking up a set of Manifold Gauges. I've try to learn everything I can about the A/C system of a 98 RR. I've found the Trinary switch, the low pressure switch, the TXV, and I'm ready.

I've got a vacuum pump now, 134a, some compressor oil and weather permitting I'm going in.

Six years ago I took the RR to the RR dealer in Baton Rouge after the A/C compressor got noisy and they replaced just the compressor, it's a RR compressor part. Total over $1300.00.

When the A/C system works it works great. It may be the Control unit, but I'm ready for that too. Either way I'll have a new system.

I'll post the results