Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Peter Frederick
Jumpeingr 5 and 7 is what the relay does, so your compressor is good and the clutch coil conducts enough to at least spin it, but that does not mean the KLIMA is good. As I said, the PBCU switches on the compressor by grounding the wire from the low pressure cutout switch, so if the KLIMA

Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Kaleb C. Striplin
If the ovp relay was bad you would also not have any tach or electronic idle control, correct? Sent from my iPhone On Jul 14, 2013, at 8:09 AM, Peter Frederick psf...@earthlink.net wrote: Jumpeingr 5 and 7 is what the relay does, so your compressor is good and the clutch coil conducts

Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Peter Frederick
More than one circuit in there, you can lose one but not the others, I think. Good luck, I hate tracing down automotive electrical problems! One last thought -- make sure the ground at the PBCU is good Peter ___ http://www.okiebenz.com For new and

Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Kaleb C. Striplin
So I ran a test wire from the plug on pressure switch to ground and compressor started up. So we either have a wiring issue to the pbu or a bunch of bad pbu's? Sent from my iPhone On Jul 14, 2013, at 8:09 AM, Peter Frederick psf...@earthlink.net wrote: Jumpeingr 5 and 7 is what the relay

Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Peter Frederick
That is what I would say. Check the ground wire for the PBCU -- no ground = no operation. I'd suspect the wiring on that age car though -- 95 was right in the middle of the magical disintegrating insulation period. Every wire in the car is subject to that problem, not just the engine

Re: [MBZ] Why is my ac not working?

2013-07-14 Thread Benz Hogs
I'll give you $500 for it. Luther KB5QHUForest Park, IL '98 ML320 Max (168,xxx mi) On 7/13/2013 9:40 PM, Kaleb C. Striplin wrote: I had one clutch fail, but have had many klimas fail. This one has me baffled. Sent from my iPhone ___

[MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I have been jacking around with this 95 e300 for a couple of weeks. Ac is charged and compressor kicks in when 5 and 7 at Klima are jumped. I have run thru test in manual and my suspect is pbu not working because I am not getting 12 volts at the pressure switch or what is it pin 10 on tr Klima?

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Peter Frederick
The KLIMA Is probably bad -- the signal goes from the PBCU to the KLIMA to the low pressure switch on the receiver/dryer. If the KLIMA relay has burned contact, it won't switch the compressor on no matter what you do as the clutch current goes only through that relay contact set. Check

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I have also tried about or 5 different klimas also. One out of my other 95 and several out of 2.5 that I know work in those cars but do have the 12th pin for temp sensor cutout that the 95 does not. I pulled the Klima apart and I do not see anything that appears burned. In prep for the test it

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Peter Frederick
The PBCU provides a ground to the voltage signal, so I suspect you don't have voltage at the switch due to a failed wire somewhere between the battery and the pressure switch. I almost forgot -- some engines are equipped with a wide open throttle switch to disconnect the AC compressor at

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Dieselhead
The KLIMA Is probably bad -- the signal goes from the PBCU to the KLIMA to the low pressure switch on the receiver/dryer. If the KLIMA relay has burned contact, it won't switch the compressor on no matter what you do as the clutch current goes only through that relay contact set. Check the

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Peter Frederick
I've only seen one failed KLIMA so far, but it was in the car where the clutch coil shorted. Burned the internal relay contacts. They can also start to leak and get corroded, but failure is no more common than other failures in MB relays. Peter ___

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I checked for cont between the switch and pin 10 of Klima, it was good, pin 1 and ground, it was good, switch and pin 7 I believe of pbu it was good. Pin 13 at pbu is power I believe, if I put positive there and neg pin 7 I show less than a volt, like .6 or something. I even ran a test wire

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I had one clutch fail, but have had many klimas fail. This one has me baffled. Sent from my iPhone On Jul 13, 2013, at 8:59 PM, Dieselhead 126die...@gmail.com wrote: The KLIMA Is probably bad -- the signal goes from the PBCU to the KLIMA to the low pressure switch on the receiver/dryer. If

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I was something online about a failed Klima, having a couple of small relays inside the box, remove the cover and clean the contacts. I pulled the cover off this one and I do not see anything that looks like mini relays, it's all computer circuit. Sent from my iPhone On Jul 13, 2013, at 9:36

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Peter Frederick
You might try grounding the low pressure switch wire that goes to the KLIMA with the engine running. This should engage the compressor if the KLIMA is good as the only signal to the KLIMA from the PBCU is a ground. If it does not come on, there is something wrong with the KLIMA or

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
I will give that a try tomorrow. If it runs I assume it indicates what? The pbu or wire between it and the switch is bad or wire to Klima is bad or what? Sent from my iPhone On Jul 13, 2013, at 10:55 PM, Peter Frederick psf...@earthlink.net wrote: You might try grounding the low pressure

Re: [MBZ] Why is my ac not working?

2013-07-13 Thread Kaleb C. Striplin
Ps with the wire jumpers between 5 and 7 at the Klima compressor runs. Sent from my iPhone On Jul 13, 2013, at 10:55 PM, Peter Frederick psf...@earthlink.net wrote: You might try grounding the low pressure switch wire that goes to the KLIMA with the engine running. This should engage the