Electrical black out... any suggestions welcome

[FreeOfThoughts]

Hey everybody, I have a 99 Si that is not a daily, i got in it the other day for the first time in a couple weeks flipped the key and the battery was a touch low (lights were very dim) so i did not even try to crank it over, I grabbed my daily, went to jump it and when i put the key back in no lights worked, nothing worked, i let it charge for a sec, tried it again and the horn started blaring but no lights, nothing else. I quickly unclipped the horn as it was really annoying.

I have checked the main fuse box, fuses check out, i checked the grounds they look alright, i charged the battery and still get nothing. I do have an alarm system on the car but it was off, is there any chance it could be wired to trip and shut down the car if it (the car) receives a large gain in voltage, and if so should i try to unplug the ecu to reset maybe whatever happened? any suggestions before i start thinking about calling someone else or spending money. Thanks

 

[RonJ]

Swap the battery from your daily into the Civic. Does the engine now start?

 

[FreeOfThoughts]

Tried it when it happened and still no response. I hooked the jumper cables up properly btw, and it seems more like something tripped over something got fried but I don't own any good testing equipment so I am asking before I have it looted at and towed somewhere. Thanks again for any help.

 

[RonJ]

Does anything electrical work -- headlights, hazard lights, cluster warning lights?

 

[FreeOfThoughts]

Nope, nothing interior or out, and it drive fine the last time out and had dim lights before I jumped it. A friend suggested pulling the ecu harness to reset things as a limp mode type of last resort. RonJ, I appreciate your constant efforts on here, is there a quality testing tool I can use or rent to trace voltage thru lines and grounds that can pick up a snag in the flow of juice? I'm just being patient with it for now.

 

[RonJ]

Remove the battery ground wire attached to chassis and clean it and the bolt with a wire brush. Do the same for the battery post connectors.

If that doesn't help, buy a digital multimeter to troubleshoot the problem. Harbor Freight Tools sells an adequate one for $3-4.

 

[FreeOfThoughts]

Cool, i am charging the battery over the weekend and i hit the posts already with a brush. I'm going to go thru all the grounds next, I'll work on it next week when I can, I'm busy this weekend and get back with results thanks.

 

[FreeOfThoughts]

Thanks for the suggestions i finally got around to working on in and found that the main 80A battery fuse had popped. I had already replaced the 40A ignition fuse but was still hung up. The filament was touching and with a tap it would connect and work but with another bump it wouldn't work. Simple problem. Now owning a test light, i have a new friend in the tool box.