Sometimes my car does start

[yogi_123rd]

I have an interesting problem. It started this winter and persists into the spring. Car always cranks, but won't start - Sometimes. In order to start the car, I have to roll down the windows. It takes five or ten minutes of toggling the window switch, - relays softly clicking - then louder and eventually the windows go down. The car then starts.

Door locks don't work, either. They hum like low power as the windows do. I suspect all or most items controlled by fuse box number 2 under the glove compartment are affected. Most notably, the fuel pump relay is in this fuse box and could be the cause of the car not starting. Wipers, lights, and the radio works and the engine cranks.

The problem seems to be I have no/low power.

Now my question: What controls the power going into fuse box 2? There are two relays in that fuse box - the "Retained Accessory Power Relay (IGN)" and the "Retained Accessory Power Relay (Accessory)". Do they control the power when the ignition is turned on.

My problem behaves like a bad relay - intermittant as it is.

[HotZ28]

The device that controls the courtesy lights and retained accessory power (RAP) is the body control module (BCM). RAP, it is part of battery protection and will cut off all power to accessories within 10 minutes after the driver exits the car, or when the lock is pressed on the remote. If you will notice, after you turn off the ignition switch and sit in the car (do not open door) that all accessory power remains on for 5-10 minutes. During this time, you can listen to the radio, open & close windows, move seats and numerous other things, and then all of a sudden, the power goes off. (The timer expired)! If yours is not working like this, I would suspect the BCM or RAP module. The module should be clipped to the bottom of the fuse block passanger side. It’s black, and about 2" X 3", with 6-8 wires plugged into one of the narrow sides. It’s a pain to see, but easy to get out. You might also try changing the relays with one for another purpose. They are all the same in that panel.

[yogi_123rd]

The RAP is working normal.

My question is basic - how does power get into fuse box 2. Does it go thru a relay?

[HotZ28]

I do not have a wiring schematic for this particular car handy; however, I have never seen a fuse & relay panel powered by a "relay". I would guess that the power would come from the other fuse-relay panel, or a fusible link. Maybe someone with a schematic could help clarify.

[yogi_123rd]

You may have something with the RAP relay being bad, although the symtoms are different.

A sticking relay would keep power on after 10 minutes and not shut off.
I think I may have a relay with poor (high resistance) contacts.

I'll know for sure when the problem happens again (usually in colder weather). I'll open the door (to shut off the relay) and try restarting.