Utah rewire help

[demoktm]

Ok so i have a 92 2655. Pulled the batterys out for winter didnt mark the wires now i have a mess. Trim gauge not working rpm jumping all around or will read like 2500 prm tap it and it will go to 3. Volt meter jumps all around. Ive called my local shops to see if they do or could refer me to someone to re wire my dash clusters. All shops said they will only do 95 and newer. So where does a go guy to get the rewire done here in utah? Or maybe a diagram of wires and colors. When i looled behing the dash someone has already cut up wires. The tack has a red and a black wire the black wire was linked with 2 more black wires and the red one got ran to a purple one but could not trace that purple to the back. Just to give you an idea of what im working with. Any help would be great thanks!

 

[alldodge]

Howdy

Knowing you have a 92 265 doesn't tell us much of anything. So right now we have :noidea: of what your working on other then were pretty sure its a boat.

What engine, what drive?

 

[Chigwalla]

It was pretty common for a while for OEMs to use the instrument ground as a dash DC ground and it creates exactly the symptoms you describe.
To check, move all of your DC grounds onto a dedicated ground bus with its own lead back to the batteries and keep only the guages grounded through the control harness. The only other circuit that I'll generally put onto an instrument ground is the sender ground on a 2-wire fuel tank sender.

Same goes for the purple switched power lead. If you use it only to fire a relay, you'll clean up a lot of electrical noise.

Pulling the batteries out shouldn't make a mess since you're only 'allowed' four terminals on a post.
Sounds like you might also need to move some leads onto dedicated buses.

But, like AllDodge said, it would help to know more about what you're working with.

 

[demoktm]

Howdy

Knowing you have a 92 265 doesn't tell us much of anything. So right now we have :noidea: of what your working on other then were pretty sure its a boat.

What engine, what drive?

I have a 91 5.7 merc motor alpha1 out drive.

 

[alldodge]

Being a 91 I'm thinking a TB-IV ignition. In the link below use the V6 for TB-IV, the wiring is the same. Further in there is also the instrument wiring diagram

http://www.boatfix.com/merc/techbk/96/96hgd4.pdf

Does sound like the PO used all black to replace about everything.

 

[Bondo]

Ayuh,.... If the problem started when puttin' in the battery, why would ya think the problem is under the dash,..??

I'd start at the battery myself,....

 

[demoktm]

Ayuh,.... If the problem started when puttin' in the battery, why would ya think the problem is under the dash,..??

I'd start at the battery myself,....

Well i have and im pretty sure i have that end figired out. Here whats going on. Boat at idle 12v as i throttle about 1500 the volts go up to 13 13.5. On bank1 same rpm range bank 2 at 2k prm the volt meter is pegged light bright up like stars and started a fire behind the instruments panel. But if i put the selector to all it wont peg the volt meter. Also my fish finder always says low volts even with volts at 13???

 

[alldodge]

bank 2 at 2k prm the volt meter is pegged light bright up like stars and started a fire behind the instruments panel.

Might have bank 2 in series with bank 1, and if so you have 24V instead of 12

 

[mla2ofus]

This is hindsight, but before removing batt(s) take a picture(s) of wiring, print it and store it where you can later find it. Like maybe in the batt box.
Mike

 

[demoktm]

Might have bank 2 in series with bank 1, and if so you have 24V instead of 12

I only have the ground connecting the 2 batteries. That i assume is the correct way

 

[alldodge]

Yes, all grounds are connected together.