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JHZR2 · #5 04-19-2007, 07:58 AM

Quote:
Originally Posted by JHZR2

Now, option #2. Say I obtained a new or good used Klima relay. Could I modify it such that of the three functions it protects for, i.e. 1) Signal from the CCU going through the Evap. temp switch and the low pressure cutout switch. This signal tells the Klima to close. 2) Signal from the kickdown switch. This signal tells the Klima to open. 3) Signal from a temperature switch. This signal tells the Klima to open if the temperature it above the setpoint. 4) Signal from the tach.

Could I somehow modify the klima such that the tach signal (not present) is always set in the relay to be correct and so the AC can operate? This way, assuming that all the rest of the wring is intact, I still get the low pressure protection and the kickdown shutoff conveneince.

Is this possible?
I don't understand what you want to modify on a perfectly good Klima? If the Klima works properly, you get the protection you seek and the dropping of the compressor during kickdown.

Quote:
Originally Posted by JHZR2

Finally, option #3: assume that all the connectivity to the Klima other than the tach signal is still in tact. Also assume that it is not smart/possible to modify a working klima to operate the rest of its logic without the tach signal. Could I then buy a different relay, use the pins from the klima setup, and have the relay operate such that if the CCU calls for cold air, it closes unless only two options, kickdown switch or temperature signal? That is, use a relay with one less option to cause it to open. I assume that with a single different relay (not necessarily drop into the existing holes) or a set of simpler relays wired up some way, I could gain this functionality.
Again, I fail to see the need to reinvent the wheel.

Well, the problem is this... The Klima will not work properly if everything that Ive found in my research is correct. Apparently though it is unknown why an RPM signal is sent to the Klima, it is necessary for its correct operation. However, since my 85 car doesnt have an 85 engine, it can't get the correct signal through he EGR computer and sent along as a normal klima and egr relay equipped car would.

Thus my problem...

My angle is that it would be nice to have the temperature protection and disengagement at kickdown that was designed into the system. The problem is that if I just jumper around the klima alltogether, I loose both of those options.

Is it a biggie? Not really, but it seems that there would be a way to solve the problem with either a klima relay mod, or a different relay being used. Relays are relatively simple things from what I know.

I cannot imagine it would be that tough to get the protections and conveniences that I desire with a slight mod.

Let's assume that the Klima is set to close for all times that the ACC calls for cold air, except for four cases - temperature irregularity, presure irregularity, kickdown switch is closed, and rpm signal is not present. It seems that these are the four Klima opening faults that it is designed to disengage the AC system for.

So, this means that the relay is set up in some way such that all is well unless those four faults have a 'signal', which defaults to making the klima open. So, there would have to be a way, jumpering or otherwise, where the 'correct' signal for the RPM inpt, could be forced inside the relay. This way the relay always thinks that the RPM signal is correct, it is fine, and so the klima relay will never open due to tachometer input.

By bypassing the RPM fault in the klima, the relay goes from having four protections to having three This is my hope and desire - to maintain the protections designed into the klima system without having to have the correct rpm input signal. My two options to gain same are depending upon if it is thought to be easier to modify a relay that has four potnential fault inputs that would cause it to open, bypass one (rpm input) to maintain the other three, or if it would be smarter to find another relay that is designed to only have three potential inputs that would cause it to open. There are all sorts of relays out there, and Id guess that a bit of research would locate the right one.

Any thoughts???

Thanks again for considering my crazy idea!

Best,

JMH