Electrical Problems *No Power anywhere*

[Deathseeker31]

Hello Everyone,

I have been trying to do some research to see if I can figure this problem out without posting but have had no success. I was retorquing my head since the motor was freshly rebuilt a few months ago. I made the mistake of not disconnecting the battery, I know bad move, and managed to tap the alternator ground with the torque wrench. This caused me to loose power to the car completely. It feels as if the car doesn't have a battery but it does and it is fully charged as well.
I checked all fuses they were fine except for the alternator fuse in the fuse box next to the battery. I replaced that fuse assuming it will fix it but no luck as well.
I double checked all the fuses once again to make sure none of them were blown. All the grounds have a good contact as well.
Does anyone have some suggestions as to what this could be? I would think if I damaged the ECU my door lights would still turn on? I'm kinda stumped and don't know where to go from here. Thank you everybody.

 

[Dan_Gyoba]

Check the main fuseable link. That's the wire connection at the battery to the main fuse box. Use a multimeter to test for battery voltage, and you'll see where it's blown. Don't replace the fuseable link with a piece of regular wire, get a proper replacement.

 

[Deathseeker31]

Dan thanks for the advice.
I have a 7MGTE, my apologies for not specifying that earlier. where the fusible link goes on the turbo model there is an ALT fuse which has been replaced. Is this what you were refering to? I tested my battery voltage and it is at a steady 11.5volts.

 

[Dan_Gyoba]

There's also a fuseable link. I could only find the one reference to it in the TSRM, (http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=ST&P=2) where it describes the fuseable link being blown and tells you to replace it.

Basically test for continuity at various locations. First, test that the Neg terminal of the battery has continuity to the engine block, then start testing where you get and don't get +12V. The main starter terminal does NOT go through the fuseable link, so checking that will tell you that you've got a good connection to the battery post, but that's about it.

The base of the ALT fuse is immediately after the fuseable link, so +12V there means that it's not the fuseable link. No power there pretty much confirms that it is. About the next place that I could figure out to test would be the horn/hazard fuse, which is one of the first things that does not go through the Alt fuse from the battery. Going through it, the ignition switch is a good place to check.

 

[Deathseeker31]

I was not aware that there was a fusible link as well, I see the reference on the TSRM but the actual link I am unsure of where it is located. You mentioned "the base of the ALT fuse is immediately after the fuseable link.." the ALT fuse goes bolted to two wires that go to the body harness. Would one of those wires be considered the fusible link? I will get back to you tonight with the numbers on the readings for continuinty and seeing if I have 12+ off the ALT fuse. Which wire of the ALT fuse do I test? there are two. thank you.
I am not an expert on electrical so please bare with me as I try to understand everything and fix this issue.

 

[Dan_Gyoba]

No problem.

The fuseable link looks like a regular chunk of wire with (IIRC) ring terminals at either end.

As to which side of the fuse, if the fuse isn't blown, either end should be the same. If you've removed the fuse then check both sides. Only one side should read +12V. If neither does then the fuseable link is blown. I've got a replacement link somewhere, but haven't seen it in years.

 

[Deathseeker31]

so just to give an update for those that are wondering and for those that looked around. I tested the connection on both sides of the alt fuse and one side read +12V and the other read a little bit less. What I did notice was that after I rebolted the fuse back up one of my bolts for the fuse box was loose I tightened it and I got power to everything again. I am not sure how that all worked out but I have power with no problems what so ever. I think it was the alt fuse initially and it was possibly not grounded correctly when I reintalled it?

 

[SideWinderGX]

The fusible link goes in the same place as the main alternator fuse...you either have one or the other, you don't have both. Either one will work fine.

Bad connection with the fuse would cause some problems, yes. So it runs normally now?

 

[Deathseeker31]

sidewinder yes it runs normal now. Thank you.