It started as a low TPS voltage code which clued me into the fact the battery voltage was all over the place. I had the battery and alt tested. they check out. Now I am looking for a wiring issue.
I will do a recap on Wednesday or thursday when I have some time just to organize the actions and findings into a more readable format.

I appreciated all of the help from you guys!

 

correction:

Fort what it is worth..and it is worth a lot....or you can have electrical problems.

The wire from the junction block in the battery box....that runs through the frame and to the alternator is a 6 gauge wire and it DOES have a fusible link in it which is a 10 gauge fusible link.

I had a feeling I was right..but just needed to double check.

Just remember that the only two wires that are not protected are your battery cables. EVERY other wire in the car is protected by either a fusible link or fuse...or circuit breaker.





The junction block is in the top right corner of the photo...and you can see the fusible link (in blue)also.



This gauge chart verifies that the wire is 6 gauge and the fusible link is a 10 gauge.

DUB

 

Thanks for the correction, I looked in my book today at the other house and yep, I was wrong. Well, it was about 8 years ago when I did it and couldn't remember for sure even on the wire gauge. Thanks again.

 

I did find a fried fusible link to the pos. junction from the ALT. Unfortunately it (the fusible link) was inside the frame rail and replacing that wire was a PITA.

I have a different diagram though



my assembly manual shows the wire running through the frame rail straight to the junction w/o a fusible link.

The wires I found were 8awg. Not to discount you DUB but unless that assembly was replaced as a unit there in no way two 6ga wires would fit inside of it.
I tried to get a 6ga one in there ....all day actually...w/o any luck.
(I did manage to make a few new swear words )

Now I am more confused than ever. My diagram and yours do not match what is on my car. Neither matches the assembly manual.

If the alternator, pos. battery cable and the fused wire for the ECM meet at the junction box, would the pos feed from the ALT really need to be fused? Everything else in the car is connected to the positive cable at the starter and those have fusible links

I know this is off topic but it helps me to understand.

here is how I see it in my car. I did not include the fused ecm wire from the pos. junction in the battery box
(enjoy my ninja level artwork)






Thank you all for your input. I am learning a ton and every mistake/problem is an opportunity to learn. I truly appreciate the effort from all of you!!

 

I think your doing good .your taking direction from several guys and doing well .But after you know everything and become a crossfire guru then you have too help all the new guys.

 

That's the plan.....I hope

 

OK, I'm looking at my GM manual here at the house right now and it is like the one DUB used as far as the diagram goes. ALL wire sizes in that manual are in Metric sizes and according to the diagram that DUB and I have the RED positive wire running through the frame is 8AWG, not the 6AWG that DUB pointed out. The fusible link in that same diagram is 12AWG. Using the WIRE SIZE chart in the manual that's what it works out to since it is a Metric to AWG conversion chart. Point is, I have another manual which is not the colored diagram version and could just be a copy of the GM manual and it may be different like the one you presented here. My wife is coming up to the Phoenix house today and I'll have her bring it up here and I'll have a look and see if they match or not.

Generally speaking, a fusible link is 4 sizes smaller than the wire size it is protecting, the GM manual shows it as three sizes smaller. I guess GM engineers know what they are doing...or do they? Anyway, DUB was correct that they all need protection in one form or another.

I would like to pull my wire out of the frame rail and verify it, but it is to much of a PITA, so I won't. Only because I'm beat from pulling the steering box out last night for more mods to the 82 I'm doing. Another PITA, but worth it.

So, it looks like you are definitely learning a lot about CF cars and before its over you will know a ton more. Good luck with your troubleshooting and hopefully you don't run into any Bubba mods, they can be killer.

 

DANG IT!!!!....I had a TYPO!!!!

YES...the wire is a 8 gauge....heck..it is even shown the the chart....I saw it...understood it...but I typed it wrong.

icpr4u,

You hand drawing is not correct...and this because that the wire from the junction block...going to the alternator HAS TO HAVE A fusible link or some type of circuit protection. It is your car and do as you like...but you are really pressing your luck in not having a fusible link in that wire.

But the page in your manual you posted IS correct..and that is because the wire going to the alternator...is coming off the starter solenoid...and THAT wire going to the alternator has a fusible link in it. SO...basically...the stud on the starter solenoid in your drawing is a junction block.

And the reason the wire is different gauge in your drawing ...versus what I posted is the length of the wire.

AND...also keep this in mind. the 'pig tail' wire coming off your positive battery cable going to the junction block MUST be at LEAST a 8 gauge wire. SO if somebody got in there in the past and cut off the end and butchered it with other wires and b.s. And that short wire from the positive battery cable area to the junction block is smaller than 8 gauge...it should be corrected...

DUB

 

Your drawing is just fine.

IF you are looking in an ASSEMBLY MANUAL...they will not show the fusible link in the drawing...because the fusible link is a part of the wire they are showing how to install.

I am sorry that I typed out the gauge incorrectly...but if you looked at the schematic...you would see the gauge wire size is labeled as an 8.0...which when you look at the chart I posted...it is an 8 gauge wire.

SORRY for the mix up.

YES...GM used both wire routings. BOTH a re correct...including the fusible links.

YES...that wire REALLY needs to be protected. 'Google' fusible links and fuses and read why these are used and the reason they are used.


And that is CORRECT. Like I wrote...the ONLY two wires or cables that are NOT protected with a fuse, fusible link or circuit breaker are you battery cables...and that is it.

*** Whatever this is worth*****
When I am wiring up a custom job. I am still a fan of using fusible links becasue what they DO and how they act...which is NOT the same as a FUSE....but I also will use the new style Maxi-fuses...and just about everything you can think of.

GM has changed their dynamics in wiring in the new Corvettes...because I have seen that they are going more towards using fuses instead of fusible links. maybe it is being done for quick repair times..and not so much it actually being a better design.

DUB

 

Thanks guys!
I think you've given me a great start
It is wonderful that you take the time to explain the reason for why things are the way they are. It will definitely pay off.
Gonna be a few days before I can get to it again.
I'll keep you posted.

DUB
I didn't mean to bust your hump about the wire gauge. Just trying to do it correctly

 

Its OK to 'bust my hump'....I ALSO want to try to provide correct information.... so.... if I am incorrect...I have no problem in admitting I made a mistake.

For what it is worth..the fusible link is 6 inches long and here are photos of that wire assembly out of a car like yours that I have saved.








DUB

 

Dub
Your pic is exactly what I had in my car. Thank you for going the extra mile!

Can I just put that link in the engine compartment where it's easily serviced instead of under the battery box?
My fusible link was tucked inside the frame rail. They must've built my car Monday morning after a long weekend

 

Putting it in the engine compartment won't protect the wire against short circuits. The protection has to be at the source end of the wire, not the load end of the wire.

 

Honestly...try not to re-invent the wheel...put it back like it was..because...it is not that hard to service once you remove the wire from the alternator and the clamp that holds the split loom. In the scope of thing i do daily...that would be a 'walk in the park' compared to some of the things I have to do on a daily basis.

That is how the wire was made..and did not have to do with being a 'Monday car after a long weekend'. If you look at the schematic I posted...you can see the fusible link is NOT at the end of the wire.

If you need me to measure the wire from where it attaches to the junction block and to the fusible link..I can do that...no problem at all....in case your wire is all screwed up.

THIS does make a difference!

DUB

 

No need to measure. Thanks for the offer though.
I'll just put it back the way I found it. (also the same advice I got from my mother)
I should be able to get to it Monday.
I will report back my findings.
Thanks again for helping out. You guys are great!

 

I got the fusible link and alt positive cable replaced and all the associated connections were cleaned and reinstalled.

Fired it up and it is charging at 14.4 v (according to the multi meter) but WinALDL says battery voltage is 18-19v

Any guesses as to what to check next?

 

check battery

 

it checks out.
The winALDL data seems suspect.
When I have problems it says the car is running with 5v battery. It will die shortly after and start right back up.
I am going to try to recreate the problem this week and check voltage at the ALT and battery when it happens

 

I would check for clean connections.

 

The fuse holder in the battery box is for your ECM, fuel pump relay and oil pressure switch..

If you are absolutely certain the alternator is charging at 14.4 volts or there abouts....which is fine....but you are getting another value with another tool....I would be possible suspect of that tool or the ECM.

Make sure you also have very good clean grounds.

DUB