I developed a cold no-start last week when I tried to drive home after work. I went to start and acted like a dead battery, no gauge, fan, clock, radio and buzzer. However, the dome light was dim and the rear window worked normally with the key. I'm at work and all I had was my free HF DMM (which failed LOL) and a mini leatherman tool. The symptoms led me to believe it was a fuse. I pulled and visually checked the big 30A and 40A AM fuses, visually inspected the 80A and they looked fine. I checked the usual suspects on the bladed fuses and they looked fine. I'm at work and stumped. I noticed though after pulling and checking fuses the dome light was back to full brightness. I put the key in and everything came back, radio, gauges, fan, buzzer, clock. I turn the key and it starts. Woo-Hoo! I can get the 4Runner home.
That night I recreated the problem. I turn the key to run and everything works. I go to start it and everything dies. I wiggle the AM fuses and things come back. I try to start and everything goes dead. Well this officially became a weekend project.
I check voltages at the AM fuses and they look fine. I pull the 80A and it seems fine. I check resistance and they seem fine. I inspected all the connections in the relay box and they looked solid. No wiggling, no wire damage and no corrosion. Since it looks like circuits for both AM fuses I start looking at the 80A. I clean all the contacts put it back together. I go the the F1 connector by the airbox and clean those contacts. Nothing really looked corroded. Nothing really looked out of place except I did find an abandoned trailer light box behind the airbag that was scotch locked to the tail lights in the cab. I pulled and fixed that. It couldn't have been involved, but what the hey.
Everything works now and has since last Saturday. First, I am a complete loss at the symptoms. The AM fuses were almost acting like breakers. I have no clue how to explain those symptoms.
Anyone smarter than me have any ideas? That should include everyone. I didn't do any load testing which I guess would be the next step. While I'm glad the 4Runner is working, I'm not a fan of self-healing electrical problems.
That night I recreated the problem. I turn the key to run and everything works. I go to start it and everything dies. I wiggle the AM fuses and things come back. I try to start and everything goes dead. Well this officially became a weekend project.
I check voltages at the AM fuses and they look fine. I pull the 80A and it seems fine. I check resistance and they seem fine. I inspected all the connections in the relay box and they looked solid. No wiggling, no wire damage and no corrosion. Since it looks like circuits for both AM fuses I start looking at the 80A. I clean all the contacts put it back together. I go the the F1 connector by the airbox and clean those contacts. Nothing really looked corroded. Nothing really looked out of place except I did find an abandoned trailer light box behind the airbag that was scotch locked to the tail lights in the cab. I pulled and fixed that. It couldn't have been involved, but what the hey.
Everything works now and has since last Saturday. First, I am a complete loss at the symptoms. The AM fuses were almost acting like breakers. I have no clue how to explain those symptoms.
Anyone smarter than me have any ideas? That should include everyone. I didn't do any load testing which I guess would be the next step. While I'm glad the 4Runner is working, I'm not a fan of self-healing electrical problems.