First post on the forum, have been lurking for a while though.

1970 Toronado GT, was attempting to set the dwell on the distributor while engine was running, shut it off so I could get the Allen key in easier, then when I went to turn the car back on, there was a large spark (dare I say explosion) from the rear of the engine bay. From what I could tell, I accidentally grouded out the distributor to the engine via the Allen key, and once I quickly pulled that out, I attempted to start it again. There was a starter click and the car lost all electrical power. I was able to go in with a test light and see how far power got, I could see there was power to the starter motor and through the starter solenoid. There was no power at the coil, headlights, or anywhere else on the vehicle. There was power to everything there should be up to the point where it clicked and everything lost power. Need advice as to what likely broke and would need replaced, hope we can figure this out.

UPDATE: If i wait for a time, power returns to everything, but goes away again upon first crank.

 

You have a loose or corroded connection somewhere. Unfortunately there is no easy way to find it. You have to trace the circuit all the way to the coil, checking and cleaning all connections. Don't overlook the firewall connector.

 

Clean the positive connections at the battery, starter, horn relay, and block. Also clean the negative cable connections at battery and block.

 

Dumb question, but what/where is this? Was told i would have a fusible link near it that could be my issue

 

Download the 1970 Toronado assembly manual from the sticky threads:

https://classicoldsmobile.com/forums...manual-157088/

These manuals are awesome for locating things like that.

 

Is it possible the horn relay itself went bad? I noticed it was clicking before when I had a door open, and upon testing it with a test light everything on the main terminal had power, but it seemed like the connectors on the bottom weren't getting it. Power to the horn relay but not to the coil. If the part is good I don't want to drop $100 on a new one, but if it's my potential fix then I'll do it. Is there a possibility my problem is at the starter?


I was looking through the Assembly Product Manual (really helpful by the way), and saw in a diagram what and where the horn relay was as well as the location of the fusible link. I got a picture of the area but I'm not entirely certain if what I'm seeing is in fact the fusible link. Whatever it is, it had current on both sides. Thanks for your input so far

 

The horn relay really doesn't have anything to do with the power to the rest of the car other than being a junction block where the positive battery cable connects to the other circuits. The relay is attached here out of convenience for the horn. I hope that makes sense.

So, lets say for example, that your horn relay was indeed bad......you'd have no horn, but your car will function just fine. Now, if your fusible link was blown (it should be part of one of the wires coming off the horn relay junction block) that will definitely cause a no start. The fact that you're getting power occasionally tends to lead towards you having more of a bad connection somewhere, possibly on the ground side of things.

If I was you, the first thing I'd be checking for is the connections of the negative side of the battery and also where it connects to the engine block. Make sure you have a good connection here. A decent quick test to tell If you have a really bad connection here, is putting your test light to battery negative and to the engine block - with the key in crank you will have a bright test light which indicates a bad connection on the ground side.

Can grab a big ol jumper cable and run it from something solid on your engine block to the neg post of the battery and give er a try.

 

Sorry for not getting back to you guys, I hate to be the guy who asks for help but doesn't report back on how it went.

I had recently replaced the negative battery terminal but neglected to clean off the old wire, and that poor connection, like you said, was causing the ground issue. I pulled that off, cutting off the exposed wire and peeling back some new wire. Cleaned it up good, then slipped it into the terminal and the engine fired right up. I was able to set points gap, dwell, and timing, and she now purrs like a kitten again. Just today, I picked up and installed a whole new battery cable from NAPA to replace the temporary style terminal for peace of mind.

Thanks guys for all your help, I will be back here again.

 

Thanks for posting the fix to your issue.