No lights-No start-Good battery!

[woodwiz]

Howdy everybody!
My appologies in advance for what may seem to be rambling. Put in a digital dash from(Dakota) months ago and it works terrific in my 70 RR 383.
Went out to go for a spin last Saturday and noticed no dome light and upon turning the key no dash light up or guage activity and of course no start.
With the key removed i don't even get the headlights to come on. The dash clock and mileage window in this unit will light on acc. I checked the battery posts and all is clean. Checked all the grounds in the engine compartment and all is good.
Put the key in ignition to on and did jump across the starter relay and all i got was light sparks. Also tried that at the starter and got the same results.
I"m scratching my head on this!!! Could this just be the starter relay is bad or do i need some more Bad ground diagnosing??

Thanks in advance!!

 

[quikbird]

Have you tested the battery to see what voltage is?

 

[woodwiz]

Yes! 12.96V at the posts
Jumping across the starter relay and down at the starter as well have produced no clicking just small sparking.
Do any of these things inhibit the headlights from lighting...starter relay,loose connection at the brain box for the digital dash,a ground somewhere i haven't found and or the key switch itself????

 

[Russ69Runner]

Will have to check the bulkhead connector. Check the fusible link. That is where I found my no spark problem. Mine was only on the brown wire. But on the other electrical connections possible a loose connection at the connector per say. Just a thought. Don't figure no head lights. Everything feeds off that connector. Wish you luck it drove me Battie looking for my problem. If you jumped the relay on the starter sounds like you don't have a good ground. What is the voltage to the starter itself.

 

[woodwiz]

I’m still trying to run down all possible grounds,there might be some still hiding. Jumping the starter relay and at the starter and getting the same results is frustrating for sure.
Power is getting through to the brain box on the digital dash so there is power going to the bulkhead which I replaced. Is their a reason when I I turn on the headlights with no key that I notice a barely lit single headlight on each side then it fades to black?

 

[woodwiz]

Got to the bottom of this issue. I’ll back up a bit and tie this to the digital dash conversion. With the original dash out with the troublesome ammeter gauge disconnected i get a more true accurate volts reading and with the alternator that was put in the car by a previous owner,the volt gauge was showing 17-18volts in digital….way too high. Researched and discovered that the alternator for a 70rr is different than a 68-69. Once I got that right alternator in the volts back to the battery showed 13v. So back to the beginning here, the current battery was at 12.96v but the battery suffered internal damage from all this big volts and I had no amps. New battery/problem solved…relieved for sure….now onto the tranny
Thanks for all the input!!!

 

[Russ69Runner]

So glad you got the problem solved Woodwiz. Sometimes things are so frustrating. But don't give up just walk away for a day or so and things fall into place.

 

[woodwiz]

You are so right sir!! As for the door jamb switch, I’m working on it. Just need a 2 pin connector and the right size threads in the door jamb.
Thanks!

 

[69hemibeep]

I was going to suggest turning the headlights on to test the battery but you got it!

 

[woodwiz]

I did learn something new about batteries through this that they can show full volts and not start the car. I must have cooked some of the plates inside when my wrong alternator sent 17-18v in to it.
Nice to have it solved. Never too late to learn. On to the tranny forum!

 

[Rapid Transit]

This seems a classic example where a test light beats a test meter.
Puts a load on the wires, connection or battery power supply
Looking at the OP it now jumps out that the OP was referring to digital indications as well that did come on.

 

[Russ69Runner]

Buy a good load tester at Harbor freight. Takes the guess work out if they are good or bad.