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CardinalFJ60
11-01-2010, 04:17 PM
So...I finally got around to putting in the new(used) guages and putting the cluster back together. I was careful to tape up the Ammeter posts so I wouldn't re-fry it. BUT...upon connecting everything and just placing it back in the dash, I touched the circuit board to the metal and it started sparking (!) Now the instrument lights are always on, but turn off when I hit the headlights, and one blinker indicator is always on. I can see where I fried the board. guages seem to all work. that's the carnage.

Here are my questions:
Is that whole circuit board live when connected? I can't imagine it is. If not, then something else must be going on.(?)
What's my next step? get a new printed board?

Rzeppa
11-02-2010, 10:33 AM
Yes, there is unswitched power available - for example, on a 40 you can turn the headlights on without the ignition key turned on. This illuminates the cluster lamps too.

Whenever working with the cluster on a 40, it is VERY IMPORTANT to disconnect the negative terminal at the battery!

Jacket
11-02-2010, 11:33 AM
Bummer - bitten twice. I still haven't mustered up the energy to replace my ammeter since I zapped it a couple years ago.

CardinalFJ60
11-02-2010, 11:50 AM
twice bitten...thrice shy. I guess I just couldn't imagine the whole back panel would be 'live'. I'll get some replace parts and try again. (sigh)

Uncle Ben
11-02-2010, 11:54 AM
You guys are gonna learn the hard way! Please, take Jeff's advice and pull the negative battery cable before working on electronics!

Jacket
11-02-2010, 11:59 AM
I've learned that procrastinating cures all problems.

Uncle Ben
11-02-2010, 12:09 PM
I've learned that procrastinating cures all problems.

:lmao::bowdown::homer:

subzali
11-02-2010, 01:07 PM
why not pull the positive?

Rzeppa
11-02-2010, 01:53 PM
why not pull the positive?

What do you normally use to loosen a battery terminal?

What is that tool made of?

What can happen if it slips and touches anything conductive?

Hint:

:weld:

Air Randy
11-02-2010, 03:51 PM
What do you normally use to loosen a battery terminal?

What is that tool made of?

What can happen if it slips and touches anything conductive?

Hint:

:weld:

True dat but one thing to keep in mind (probably not an issue on a 40): Many of the newer rigs have capacitors built into various electronics. Keeping the positive cable on will allow those capacitors to charge and touching a circuit to ground will still let them discharge even with the battery disconnected.

Uncle Ben
11-02-2010, 05:31 PM
True dat but one thing to keep in mind (probably not an issue on a 40): Many of the newer rigs have capacitors built into various electronics. Keeping the positive cable on will allow those capacitors to charge and touching a circuit to ground will still let them discharge even with the battery disconnected.

There is far less spark jump when the negative cable is pulled first. Capacitive discharge can happen no matter what is disconnected first unless the positive lead on the capacitor is shorted to ground. No amps in cap discharge so other than the knot on the back of your head when you jump back and hit the hood and the hair standing straight up scars should be minimized, however that gold ring your wearing proudly will forever brand you should you short that finger to the ammeter terminal with the batt cables still on!

Air Randy
11-02-2010, 08:22 PM
There is far less spark jump when the negative cable is pulled first. Capacitive discharge can happen no matter what is disconnected first unless the positive lead on the capacitor is shorted to ground. No amps in cap discharge so other than the knot on the back of your head when you jump back and hit the hood and the hair standing straight up scars should be minimized, however that gold ring your wearing proudly will forever brand you should you short that finger to the ammeter terminal with the batt cables still on!

Agreed! Thats why I'm saying you should pull the positive cable or better yet pull both the positive and negative and start with pulling the negative first.

Rzeppa
11-04-2010, 02:23 PM
True dat but one thing to keep in mind (probably not an issue on a 40): Many of the newer rigs have capacitors built into various electronics. Keeping the positive cable on will allow those capacitors to charge and touching a circuit to ground will still let them discharge even with the battery disconnected.

There are only caps in 2 places in a stock 40:

(1) Is when there is a condenser (old-school term for capacitor) on the distributor, and even that one isn't across the rails.

(2) Radio (when so equipped). This one would be across the rails, but I wouldn't expect more than a couple hundred F - nowhere near the stored energy found in a battery.

There's no real harm in removing the positive terminal after the negative has been pulled, but it isn't really necessary.

CardinalFJ60
05-31-2011, 07:56 AM
finally got this taken care of. the issue was that when I put the ammeter back in the cluster-pod, I forgot to isolate/insulate the leads from the back of the pod. I created a massive short. :o:mad:

everything works, I washed her up yesterday and took on the first trip since getting it bedlined. I still need to put lots of things back together and add some stuff, but "she's alive!!".

:cheers:

subzali
05-31-2011, 08:43 AM
Congrats Shawn! Post up some pics for those of us that haven't seen her in a while!

CardinalFJ60
05-31-2011, 05:32 PM
for me, this is significant...it's actually in the driveway instead of on the side of the house. :D OH...and it's clean.

It's more charcoal color than anything, but in certain light it'll look greenish or purplish. I'm so friggin' happy to have this running again.

CardinalFJ60
05-31-2011, 05:37 PM
mmmm....cruiser.

corsair23
05-31-2011, 05:55 PM
Looks purple to me :hill:

Congrats on upgrading her back from lawn art to driveable :thumb:

Oh, and don't try to fit it in the garage...judging by the picture, I don't think it'll fit :)

nattybumppo
06-01-2011, 12:22 AM
Beautiful rig! Does that bedliner help with noise/vibrations?

CardinalFJ60
06-01-2011, 08:35 AM
It does help with noise a little - mostly on that tin can 'echo-factor', and I guess I'd say road noise is slightly dimished (sliiiiightly). I'm still aligning doors and messing with seals so it whistles and rattles a ton. unfortunately the bedliner doesn't help with that. :D

I'll snap a recent pic and post it up later.

Rzeppa
06-01-2011, 01:34 PM
Sweet! :thumb: Nice work Shawn!

CardinalFJ60
06-03-2011, 11:59 AM
Sweet! :thumb: Nice work Shawn!

Thanks! Honestly, I got reeaally discouraged. I only 'mostly' know what I'm doing and I mess up all the time...it when I come close to totally ruining things I get gun-shy.

Here's the end result...