Could a trim sender short take out entire main harness?

[pantaloonz]

Hi Gang

Yesterday I finally replaced the trim sender in my 1990 OMC.

The installation was a little rough due to the logistics of it all but I got it all connected and it actually worked (I was a little surprised)

We took it out, started a little hard (hadnt run for 2 weeks) but otherwise started normally. The belt squeaked more than normal till it warmed up.

Took it to my favorite fishing spot, killed the engine and that's all she wrote.

No horn, no gauges, no lights, no START!! Before I would lose gauges but could still start, I replaced the old fuse block last week to fix that.

I did check the lanyard, and the gear was in neutral.. which is kind of moot considering NO electrical at all at the helm

note 1: The kill switch is a plunger style, I noticed when electrical was good, it will pop out 1/4" when released. Now it's staying fully depressed.

note 2: the trim tabs work fine (must not be wired into main harness?)

note 3: the bilge pump is controlled by a float switch, which is also wired direct to battery, but also wired back to the helm. I can manually engage the bilge but the bilge switch at the helm does nothing.

note 4: I took a piece of wire (I know not recommended) and ran it directly to the horn.. BEEP BEEP.

note 5: the main engine plug (the cannon connector) with the screw strap appears connected fine, but I'm going to look at that next

note 6: one of the two 50AMP fuses near the cannon connector has "play" in it, meaning I can push the one on the right in just a little bit, but not sure how hard I should push.. maybe this one is tripped?

== The item that has changed was the trim sender, I find it hard to believe that it shorted out and blew the main engine fuse? I suppose anythign is possible?

note 7: I've since disconnected the trim sender to try and rule it out.

I'm going to go look at the main engine connector, my voltmeter indicates I have power UP to that main connection area, checking all other components past that junction point appear to have NO power...

any advice is greatly appreciated. ... we are talking about 26 year old wiring here so something may be crapped up somewhere :0

-Pantz

 

[Bondo]

my voltmeter indicates I have power UP to that main connection area, checking all other components past that junction point appear to have NO power...

Ayuh,.... That sounds like yer answer,....

 

[pantaloonz]

Hi Bondo,

Do you get alerts when "dummies" like me make posts? You tend to respond so quickly.

Futher voltmeter checks turned up the following:

There was power past one of the 50 AMP breakers, the one leading to the trim pump.. hence I guess why the trim pump worked.

There was no power passing out the other 50 AMP breaker, it was difficult to test since the posts were gooky.

I removed the housing so I could get at the posts better, sure enough there was 12volts coming in from the first 50 AMP breaker, but nothing going out..

When I removed the seemingly failed circuit breaker, the incoming post broke, there is green corrosion where the bolt broke.. I guess that circuit breaker is toast.

Back to the original question, let's say the trim sender DID short out, maybe the wire housing was shitty and water got to it, could that have caused such a systematic failure like this, or perhaps these weird one off electric issues was actually this "bleeping" 50 AMP breaker the whole time?

Thougts? .. now I gotta find the damn part.

-Pantz

 

[Bondo]

When I removed the seemingly failed circuit breaker, the incoming post broke, there is green corrosion where the bolt broke.. I guess that circuit breaker is toast.

Ayuh,..... It may, or may not be the original problem, but corrosion is no doubt a problem,.....

Jumper the bad breaker, 'n see if things work, or not,....

 

[Bondo]

Hi Bondo,

Do you get alerts when "dummies" like me make posts? You tend to respond so quickly.

Nope,.... No alerts,....

But,.... I surely do spend Waayyy to much time on iboats forums,.....

 

[pantaloonz]

Hi again, with update

Ayuh,..... It may, or may not be the original problem, but corrosion is no doubt a problem,.....

Jumper the bad breaker, 'n see if things work, or not,....

That's exactly where my next test was heading. the cables are very tight and that connector did not fit well onto the other breaker, however why I made good contact to the output on the first breaker, my guages turned on and I got a nice 12v reading to my gauge. I had my son beep the horn and that also worked. I've ordered the replacement here from Iboats. I think that's a pretty solid confirmation that part had failed.

But I'm still back to the inital quandry; if I reconnect the bad trim sender (assuming it's shorted) will I blow the circuit breaker again? I want to say no. I should think the sender just wouldnt operate correcty or not at all and not blow out the entire circuit. The good news is I ordered a push to reset type so that should help me.

While I was down there, I noticed the bilge pump and fuel guage positve leads were hanging on by a thread, so I cleaned, stripped, and reconnected those.

I learned a lot about how the wiring works too (always a good thing) I was not able to piece in my head how all these components were getting power, I was assuming like the ground wires there would be a bunch of positive leads eventually connecting to the battery.. not so; the big red positive line goes into this primary junction area, through the 50AMP breakers,...THEN to the rest of the stuff.. I get it now. ... sorta

....hrm I think I should proably order a spare breaker or twoo..

-Pantz

 

[Bondo]

But I'm still back to the inital quandry; if I reconnect the bad trim sender (assuming it's shorted) will I blow the circuit breaker again? I want to say no. I should think the sender just wouldnt operate correcty or not at all and not blow out the entire circuit.

Ayuh,.... I ain't an OMC guy, but,.....

The sender should only be readin' resistance to ground, for the gauge,....

 

[pantaloonz]

Agreed,

I'm ordering a 2nd breaker now, just in case when I do reconnect it all up it blows again, I have all the tools needed to do a field repair right there if needed.

Thanks again Bondo.

I'll repost after the job is done.

-Pantz