fuses keep blowing on lights.
 

i have a problem. my lights wont work.

first thing i did was check bulbs. the one up front was no good so i replaced it. the one in rear i assume is good since i put a volt meter on the two connectors on the bottom and they had continunity.

i looked under the dash and fuse was blown. i tried to replace it and once it thoched the panel it blew. any ideas?

im gonna go and disconnect the front light then try a new fuse and then the back. any help would be great.

Re: fuses keep blowing on lights.
 

I'd say you have a short-circuit somewhere in your lighting circuit. Easy to check. You'll need a decent multi-meter, but that's a tool every boat-owner should have in his tool kit, anyway. Remove all lightbulbs. With the multi-meter set to measure DC voltage, check both sides of the fuse-holder. One side will measure 12VDC, the other: Nothing. Now switch the meter to measure resistance (ohms). Put it between ground and the side of the fuse holder that measured nothing. It should measure infinity, which would be an open circuit. I'm guessing it'll measure close to zero ohms resistance. Now all you need do is find out where the short-circuit is.

Try the resistance/continuity check with the switch for the lights both on and off. That will narrow-down the location of the short to "before" or "after" the switch. Try it with and without the rear light pole in-place.

Since the boat is, like, 99.999% non-conductive fiberglass, my guess is you'll find the short in one of the two light fixtures.

Jim

Re: fuses keep blowing on lights.
 

ok heres the news.
i pulled the stern light fixture then tried to put a fuse in. it blew

i pulled the front light fixture then tried to put in a fuse. it blew.

so that tells me i have a short either in the wires or on the switch or im runnig to small a fuse.(15amp) but i think it would have to be a short cause its blowin fuses even with no light fixtures.

and there is not a short in front fixture or the pole.

does anyone know which switch it would be cause since ive had the boat(3 months) the light have never worked. i have a 4 switch panel and it has to be one of the two left switches case the two right are courtsy and bildge.

im thinking of just running new wires. does anyone know how i would hook up new wires to switch.

Re: fuses keep blowing on lights.
 

At the rate you're going through fuses, you could buy a servicable multi-meter at Harbor Freight and be money ahead.

A bad switch would cause the lights to either be on all the time or off all the time. It has to be in the wiring.

A 15 amp fuse is more than enough for a couple of light fixtures.

When you say "no light fixtures," do you mean you literally removed the light fixtures, or simply the bulbs?

They aren't labeled? All the switches on our Mariah are labeled.

Seems a pretty easy process-of-elimation. But buy a meter, ok? Doesn't make sense to keep burning thru fuses like that.

Well... yeah. It's not hard. But neither is locating short circuits. If you can do one, you can do the other. If you can't do one, you probably shouldn't try tackling the other.

I've seen Amazon.com: Boatowner's Mechanical and Electrical Manual: Nigel Calder: Books recommended often. Perhaps you should pick up a copy of that, and a meter, before attempting to go any further?

Jim

Re: fuses keep blowing on lights.
 

Which lights are we talking about here? Nav lights or interior courtesy lights?

Re: fuses keep blowing on lights.
 

i have a multimeter. i just didnt have it on me. fuses are cheap.

ill hit it with the multi tonight.

yes fixtures were removed not just the bulbs.

both left switches say acc.

Re: fuses keep blowing on lights.
 

nav lights courtesy works

Re: fuses keep blowing on lights.
 

You are more than likely looking for a short in the wiring, but it is possible that there could be a screwed up connection/short at the back of the switch. The switch on mine is a rotary 3 position (nav/off/anchor) with a ground for the switch indicator light. Yours could either be rotary or a 3 position toggle with the same functions.

Dash schematics: http://www.mariahownersclub.com/foru...read.php?t=116

Re: fuses keep blowing on lights.
 

You'll need to understand how such a basic circuit works. I'll try an "ASCII art" drawing:

+12VDC ------- fuse ------ switch -------- load ----- -12VDC (ground)

(Where "load," in this case, is your lights.)

So all the fuse and switch do are open up the 12VDC positive path to one side of the light. Somewhere you have a short-circuit between 12VDC+ and 12VDC- (ground).

If you examine the fuse block carefully, you'll see one side has a strip running along it and the other side of each fuse holder has a Faston tab for connections. The side with the strip is the +12VDC common bus. The other side of each fuse holder is the load side. So, with the fuse out, if you measure resistance between the load side of the fuse holder and ground, with either the switch off or the lightbulb out, you should measure an open circuit (infinity). I'm guessing you'll measure zero resistance, which would be a short. But it there are dash lights (for the gauges, etc.), on the same circuit, it might measure very low resistance. (See "This confounds me," below.) Unless the short is between the fuse and switch, you should be able to use it to figure out which switch is the one for your nav/anchor lights.

There could be several things being the "load" (e.g.: nav light[s], anchor light, gauge lighting) and there could be more than one switched circuit on a fuse. (I tried to draw these, but the darned proportional fonts won't let the spacing come out right.)

You're going to have to do some painstaking wire tracing to figure out how all that was wired, I fear.

Well, you know it isn't the fixtures, then.

You just need to trace the wiring and find the short. Going by the simple diagram I did, above, you should be able to get it.

Here's what confounds me: You say you have only four switches, none of which are labeled as nav or anchor lights? That was a weird thing for Mariah to do. Of all the small boats we looked at recently, I can't think of a one that didn't have a switch complement like our boat has. Our '94 182 Barchetta has... um... five: blower, bilge, anchor, nav and courtesy on the left side. (Plus blanks for "acc" and something else I can't recall on the right.) So it's kind of sounding like the boat never originally had nav and anchor lights (hard to believe) and a previous owner added them and wired them up to an accessory switch?

In fact: You have no bilge blower??? :eek_animated:

Can you show us a picture of your dash?


Jim

Re: fuses keep blowing on lights.
 

Re: fuses keep blowing on lights.
 

next to the ignition to the right i have two rotary switches. neither are marked(p/o didn't use a cover and sun faded everything). one is fuel the other is the blower. the only other switches are the 4 on the dash.

light have to be OEM. a boat with no lights from factory????

im taking the boat out for the weekend and ill try to get some pics.

thanks alot SEMIjim and wetwilly

Re: fuses keep blowing on lights.
 

"Fuel?" What does a "fuel" switch do? (ISTR seeing reference to "fuel" switches, and wondered about that. Our sailboat has an "automatic" fuel switch atop the fuel tank that turns the fuel supply on/off when the ignition key is turned. Are these manual switches that do the same?)

Well, that was my thought. But if the OEM installed lights, one would think they'd install switches for them. Certainly they wouldn't have labeled nav and anchor light switches "acc," I would think.

You're quite welcome. Good luck with your wiring.

Jim

Re: fuses keep blowing on lights.
 

Can I add a question to this thread?

I have no Nav lights or Instrument lights. The Dock lights and courtesy lights are OK. Are they on different fuses or is there some other reason why only the Nav and instrument lights dont work?

Could there be a problem with the switch or dimmer (how can I tell)?

There is a fuse panel on the right side under the steering wheel but I cant work out how to remove the fuses to check, I know it sounds stupid but I have tried unscrewing them and they wont budge.

Also, there is a fuse bus behind the dash (near the right-hand bank of switches) that holds about 5 fuses, but only one of them has a wire going to it. Are the others spare or have some wires been removed?

Cheers

Grommett

Re: fuses keep blowing on lights.
 

Looks like you just did :) I doubt discussion about lights and fuses and so-on will bother the OP. Perhaps something will be mentioned that will help him out, too.

On our 1994 182 Barchetta the navigation and anchor lights are on their own fuse. (It was daytime, so I couldn't tell, but I assume the instrument lights come on with the nav lights. Thus they'd be on the same fuse.)

Here's our fuse layout:
Meter. Tracing. Testing. Btw: Does the anchor light work?

Are they cartridge fuses? Glass tube with a metal cap/connection on each end? They clip into the fuse-holders. You just pry them out. You can carefully sneak a small, flat-bladed screwdriver under one end and gently pry it up if a fuse is reluctant to move. Be careful! One side of those fuses is the +12VDC bus, and accidentally shorting that to ground could have serious consequences. (Tho our boat has a 35A master fuse in an in-line fuse-holder right next to the battery.) Also, the fuse bodies are glass. They're usually pretty tough, but still... they're glass ;)

I have two 6-postion fuse blocks, one above the other, on that side. The top row is filled and the bottom has only a single fuse in it--which seems to serve no purpose.

Btw: You might find this enlightening (pun intended :)): Fuse Confusion

Hope this helps.

Jim

Re: fuses keep blowing on lights.
 

This doesn't help the original OP, but your question made me think of a question on your Z model. Not sure what differences there are between the 94 and 96 models but here it is........

Since I just started mine after a 2 year layoff and haven't had any electrical issues ever (knock on wood) I don't remember ever seeing fuses on mine exept for the in-line fuse to the JVC stereo .

Didn't the Z models back in the mid 90's come with the breakers on the dash instead of a fuse block or did they have both? I know mine has a bunch of breaker pop out buttons on the left side of the dash just to the right of that row of switches. When I look at my 94 brochure it shows the breaker switches as standard equipment on all the Z models.

Re: fuses keep blowing on lights.
 

94z190talari

You may have answered one of my questions... the pop-out switches you mention could be the fuses I was trying to remove :D

That would explian why they wouldnt budge, I assume they pop out instead of blowing?

In which case I have no blown fuses so it must be the switch or dimmer. Will get to work with a test meter.

Also Semijim - not sure what you mean by anchor light?

Re: fuses keep blowing on lights.
 

That 360-degree, white light-on-a-stick at the stern of small boats. On bigger boats it's atop the bridge. On sailboats: Atop the mast. It's supposed to be on while you're anchored--thus: Anchor light :)

Jim

Re: fuses keep blowing on lights.
 

So thats what my "light on a stick" is for! :yes_grin:

Re: fuses keep blowing on lights.
 

Yup, that's what it's for :). It actually serves two purposes on a small boat: The rear running light and the anchor light. You operate both the red and green bow lights, and the "anchor" light, whilst under way. You operate the anchor light alone when anchored :).

Here's a more thorough explanation of the requirements: http://www.uscgboating.org/SAFETY/fedreqs/equ_nav.htm

Failure to display the proper lights at the proper time will get you ticketed by the water cops. If you're involved in an accident on the water and you weren't displaying the proper lights: You will almost certainly be charged, your insurance company may refuse to honour any claims, and it may make it exceedingly difficult for you to prevail in court should a civil suit arise.

Oops! I just realized you're in Merrie Olde England! :p Well, I'll leave it to you to look up the rules there. I'm guessing they're little different than they are here. (Tho, since y'all drive on the wrong side of the road... :D.)

Jim

Re: fuses keep blowing on lights.
 

I would have to assume that the laws would be somewhat the same as it is as deadly over there to drop anchor at night and not have that "lite stick" turned on and someone zooms past you (or through you) and you will surely have to change your knickers. :eek_animated: That is if you live through it... :shakehead:

Re: fuses keep blowing on lights.
 

these are all of my switches.

on the rotary one i know the one on right is blower. the one on left i think is fuel selector but not sure. its a three position. when i first got the boat it seemed like it would not turn over until i put the left on on th middle position.

Re: fuses keep blowing on lights.
 

"Fuel selector?" You have more than one tank?

I suspect that's your nav/anchor lights switch. I know I've seen others comment here about a three-position rotary switch for that purpose. If so: One position would be "off," one position would be nav lights (red/green on the bow, the white 360 degree anchor light [aka: light-onna-stick] at the stern), and the 3rd position would be just the anchor light.

Jim

Re: fuses keep blowing on lights.