Experiencing extreme battery drain. Have removed the negative battery cable and put a 12 volt lamp in the circuit. With the keys out the light burns brightly, went into the fuse/relay box in the engine compartment and started pulling fuses and relays. Found only one had an effect, when I pulled #24 (PCM power relay) the 12 volt bulb went out. Is this normal or does it point to the relay being bad?

My next step is to check the Battery Saver relay control under the dashboard.

Anybody have any help or troubleshooting info for this problem. Thanks in advance for helping out.

 

Is #30 (30amp) in the CJB hot at all times?

Pulling #113 (30 amp) in the BJB should have the same affect with the bulb.. When you remove/install the PCM relay does it 'click' What engine in the 250?

 

Hayapower - Thank you for your reply. Sorry I have not gotten back to you, but with work and not having my truck things have been a little hectic. The good news (I think) is that I believe I have found my problem. It seems that relay 1 (interior lamp relay) in the under dash distribution block was the culprit. In my initial check with the 12v lamp in the circuit I went through and pulled all the fuses and relays working by myself and was looking for the 12v lamp to go out and as mentioned before only the 1 gave me that response. Decide to go through the process again the next day only this time I had someone else outside watching the lamp and when I got to fuse #4 under the dash and pulled it my observer said he could see that the lamp did not go out but did appear to dim somewhat. Went to wiring diagram and found that relay #4 was in the circuit and decided to repace it.

Now the weird part for me. When I did the second run through I had totally dicconnected the secondary battery and had only the Positive on the primary battery connected and the Negative with the lamp in it connected. When I replaced the relay in this configuration the bulb stayed lit, which made me think I had not found my problem. I'm not sure why, but decided to reconnect the secondary battery and noticed that when I did reconnect the secondary the bulb would go out right away. Okay I thought lets check it out. Put everything back together and started the truck, All good so I drove the truck for about a 20 minute errand and returned home. Let truck sit for about 6 hours and tried it again last night and it started right up and then checked it this morning and again started right up, so it seems that the battery drain is gone. When I put everything back together yesterday I checked the battery voltage and it was 12.80 and I checked it this morning before starting it and the voltage was 12.67 so all seems okay for now.

It seems as though if I had not reconnected the secondary battery I would not have been able to see that the drain had gone away, not sure why. Any input on this. I bring this up because I think it may be helpful to someelse who finds themselve in this predicament. Thanks again for taking the time to respond to my question.