Battery Drain Testing 2002 Dodge Ram

 This one gets a quick charging system check while it is running and looks good. 

I'll be disconnecting the battery for testing but want to keep the electrical system powered up so will connect the memory saver but first, just in case, I do a quick code scan. 

The battery tests good but the tester asked for me to verify the ambient temperature was above freezing which you don't usually see unless there is a questionable test result. Mental note made. It does need a full charge so going ahead with the charge while the battery is disconnected. 

Once the current draw was measured I did find excessive draw. I was told the truck was okay day to day but battery would drain over a weekend. This amount of draw would fit into that scenario. Once you find your draw you have to determine which circuit the draw is on. That is a matter, at first of removing fuses one at a time until you see the draw drop to an acceptable range. I found the problem was on fuse 4 of the underhood block. 

The odd thing about fuse 4 having the draw is that fuse feeds battery voltage directly to the ignition switch and doesn't feed power to anything until the switch is turned on. I suspected someone had been doing some accessory wiring or along those lines. 

I went right to the ignition switch and found someone had bypassed the ignition switch on that circuit and fed the power through a relay instead of through the switch. The problem was the relay was always on. The excessive draw was the relay. 

I'll need to repair the wiring and replace the ignition switch. Getting rid of that relay and going back to original design. 

Now we have an acceptable draw. 

Thanks for reading,

Kenny@GGAuto.Repair

Checking A/C on 1998 Dodge Ram 1500

 "The air conditioner isn't working" was the complaint on this older truck. A look under the hood at the visible parts of the system and I could see the clutch cycle switch had been leaking. When refrigerant leaks from a system it not only emits the refrigerant gas but some of the refrigerant oil as well. So if you look for signs of oil seepage you can spot a leak without having to grab a leak detector or black light. In this case the only oil residue was below the cycle switch at the dryer. It looked like a small leak so I expected to find the system with a low charge but not empty. I connected the low pressure side to the recovery machine and did indeed have some refrigerant pressure. 

Now with that pressure reading you can tell there is enough refrigerant in the system that the compressor should be able to engage. You can't tell if how much refrigerant is in there. If the system is low and the compressor is engaged then the low side should be lower than you would normally expect to see on a fully charged system. When I turned the A/C on, the low side did go lower than normal and the suction hose was only cooling at 58F. Which was only slightly below room temperature in the shop at the time. 

We know the system is low but can't do a proper charge without knowing just how much refrigerant is in there so the next step is to connect the high side as well to the recovery machine and recover the system charge. 

The recovered refrigerant is weighed and reported by the recovery machine. A full charge is 2lb, we recovered 1lb 5oz. Also, like with a leak, some oil is recovered along with the refrigerant. The oil is separated into a bottle and measured so you can see how much to add on the charge. 

 This was a good time to change that cycle switch. 

Next up, evacuate to remove air and moisture followed by a system charge. 

Now it is pulling down to 39F.

On to the next job.

Kenny@GGAuto.Repair