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More tales of electrical woe...fixed

Posted: September 29th, 2010, 9:43 pm
by wytbishop
So this morning I put the key in the ignition, heard the normal beep, turned the key to the on position and heard the radio come on for just a second before turning the key to the start position and...darkness.

Zero life.

Checked the main fuse and it's intact. Checked the battery and it's at 12.7V. I looked at the wiring diagram for the starter circuit and it's very straight forward. Looked at that diagram for the ignition system and it shows a "Main Relay" which should be easy to check. The battery has been relocated to the rear for over a year now. I will check the sheath on the 4G wire through the cabin, but if it was grounded the battery would have been discharged or exploded I think so I don't see that being it. I unwrapped the harness to the alternator last weekend and I could well have done something bad when I put it back together but it seems unlikely that it would work for several days and then snafu...but I will unwrap it again and see what's going on in there.

Have any of you encountered a situation like this where something got crossed and a relay or something blew and rendered the car completely dead? If so, what was your solution? Any help would be great.

Thanks.

Re: More tales of electrical woe...

Posted: September 29th, 2010, 10:16 pm
by Newfie_dan
Yeah I had that happen once and it was an engine ground issue after I had put a 2nd engine in my buddies car a few years ago, found it pretty quickly though. Just put a test light on the starter solenoid that will let you know if you have power there or not. You can also try jumping the solenoid with the key in the on position see if that starts it.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 1:36 am
by wytbishop
No...it's deader than that. No interior lights, no life of any kind with the key in the on position. Being that there is no power to any accessory, I cannot believe there will be any sort of power to the ignition system. Even if the starter does turn, there will be no starting.

There was a trickle of power at the hot side of the starter, but only about 2 volts. Something is not connected.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 1:49 am
by solo_ryder
I'm no electrical genius by any means but it def sounds like there is a problem between the battery/alt/fuse box. Somewhere along the line power is not making it through. I would just go through any area you recently worked on and take a multimeter and test points to see if there is 12v at any point, once you find 12v then look to see where the drop occurs.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 2:02 am
by Gunny1162
My advice would be to check all of the connectors in the wiring where you were last in since it is entirely possible that the securing lock wasn't fully engaged and it slipped loose or became partially disconnected. If that doesn't work, start checking your ground points and your main power relay. Just remember to use a dvom and check for continuity and resistance values for both the coil side of the relay and the power side of the relay once it is energized. If that doesn't work then I don't know for sure.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 11:38 am
by Ryan
Testing relays is simple, I imagine you know how to do it already.

If you go through the wiring diagrams, start at the battery and move down the components till you hit the problem. probing into terminals for relays/fuses is also a good idea, to make sure where and where power isn't getting.

Also, clean your battery terminal and ground in your trunk. KISS, do the easy things first. And of course make sure your battery is charged...

make sure to check power at the ignition switch, too.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 12:14 pm
by wytbishop
I won't have time tonight before it gets dark to do much but I will get the alternator/starter harness unwrapped again and see if I can find where I'm losing my 12V. There is 12V accross the battery terminals and the 4G wire is continuous to the original battery harness eyelet so I should have 12V there. The trouble is tracing it from there. The harness is pretty convoluted going to the main fuse box and the diagrams only show the part of the harness that is pertinent to the circuit being shown in the diagram. Just a little confusing is all.

I'm pretty sure that the main fuse blew and power is not getting to the ignition switch...explaining why there is no accessory power. This does not however explain why there is not 12V at the hot side of the starter. The charging/starter diagram shows a single unfused, uninterrupted wire from B+ to the starter. I'm thinking somewhere in that harness I may have allowed that main B+ wire to contact something else...which blew the main relay.

Keep offering suggestions. It's helping. Electrics is the bain of my mechanical existance.

Re: More tales of electrical woe...

Posted: September 30th, 2010, 1:27 pm
by Daninski
I had the exact same problem you have and even after your negative comment in the other post that by the way hurt my feelings I'm still willing to help you. :D The battery + wire on the connector at the battery looked fine but was not. After taking it apart cleaning it then reassembling my car was fine. Remove them from the battery and confirm no open condition

Re: More tales of electrical woe...

Posted: September 30th, 2010, 3:08 pm
by wytbishop
Thanks Dan. I hope I didn't scar you too badly. It's just jokes man...just jokes.

I had also thought of that so I will be opening the harness up all the way to the fuse box. When I relocated the battery I removed the original battery post clamp and replaced it with a 3/8" eyelet and bolted it to the cable which I ran to the new battery location. I'll make sure it's still good. I redid all the grounds at the same time and bolted them to clean metal so I doubt it's that, but I will also check them.