matt3383

Im getting a different readin at the guage inside the car than i am at the battery and alt. What could be causeing this? The guage is suppsed to get its readin directly from the alt IIRC. If not where does the volt meter get its readin from?

The problem i am having is the voltage on the guage is reading close to right w/o the AC on and when i kick it on it drops to about 11 volts. I checked the alt and battery with the ac on and they both read 13V. The plug that goes into the clutch switch on the compressor also read about 11.7 but i dont know if that normal or low. Thanks for any advise.

Danno

The gauge will always read lower than battery terminal voltage, that is due to voltage drop in the cars wiring harness. With AC and cooling fan on at lower RPM you basically run off the battery. Basically that's normal with the CS 130 gen. I posted an article about using the CS130D gen which solves the problem. You might want to use a larger amp/hr battery, that will help. Make sure the gen is up to snuff. At a cold start with the accessories off measure the battery voltage. It should read up around 14 volts or so, usually average is about 14.3 until the battery recovers from the start discharge.

matt3383

Well i was playing around with the wiring more today and i have found that if i disconnect the high pressure switch from the AC compressor that the voltage will go back up to 13-14. So if i turn the AC on the voltage drops. I can then turn the AC back off and the voltage will not change, but if i disconnect this switch the voltage will come back up. I tried this with the clutch switch and it was good. Is there anything in the path to this switch i can check to see if its bad ?

matt3383

I went and check some continuity between some wires. The white wire from the prssure cycling switch goes to the high pressure switch on the back of the compressor in LT Blue, that checked ok. From the green on that switch to the clutch switch also green it checked out ok.

Danno

Sorry it took so long to reply, I was out of town. You are probably chasing your tail with the AC system. Any time that compressor kicks on there is a big voltage drop, first because of the current demand from the electrical system and second because it takes some time for the IAC to compensate for the RPM drop that the load of the comp places on the engine. Depending on the generator temp they sometimes do back down until the reg IC inside cools down. There is temp compensation in the gen if the field current gets too high and the IC gets above 275 degrees. The newer 130D units will shut down altogether until it cools down. If you have a bad diode(very common) you lose a phase or section of the gen. Without a heavy load the output will seem fine, but load up the accessories and you will get a significant voltage drop. The only way to test it is to have a load test done. I prefer dealing with gen repair shops for this, however most of the rebuilds I do I find either the stator solder connections burn sometimes causing failure of the diode bridge. Some cases the solder repair can fix it but I usuallly replace the diodes and brushes if needed. Don't forget to make sure the connections at the starter junction and battery ground are clean and tight.

matt3383

I fixed it. It was the Ac compressor itself.

Danno

Excellent, was the comp grinding or making noise?

matt3383

well the compressor sound normal before i worked on it. I drained out the old freon, and put new stuff back in. Once that happened the clutch started making all sorts of noise.

Trickster

When you did the freon swap did you flush the system to get all the old oil out and vaccum it down? The R12 oil and the R134A oil have a tendency to have disagreements with each other.

matt3383

Well i didnt do it myself i actually had someone do it for me. It wouldnt hold a vaccum which we found out to be a gasket that was missing on the dryer. But he said he vaccumed it all out and changed it over so who knows lol