Ballast Resistor Mounting...a quick tip

[nick_vw]

Well we put in a resistor with the new coil, bypassing the resistor wire. It only came with a pre-cut length of wire and the resistor was kind of hanging there (with unprotected leads that could short out)....My buddy grabbed a zip tie and put it on the cold water intake line..I was worried it might melt the line so I wrapped in electrical tape first...After 45 mins the engine gets a little rough and progressively worse, coil is overheating AGAIN. Luckily, one of my friends new the head mechanic at the marina, and he spotted it right away. Cold water intake keeping the resistor too cold, therefore not heating up and limiting the current to the coil :facepalm:

So just a tip, external resistors need to heat up in order to work properly, don't attach to cold water line (only someone dumb us would do it in the first place)

 

[chrisrooter]

Re: Ballast Resistor Mounting...a quick tip

Well we put in a resistor with the new coil, bypassing the resistor wire. It only came with a pre-cut length of wire and the resistor was kind of hanging there (with unprotected leads that could short out)....My buddy grabbed a zip tie and put it on the cold water intake line..I was worried it might melt the line so I wrapped in electrical tape first...After 45 mins the engine gets a little rough and progressively worse, coil is overheating AGAIN. Luckily, one of my friends new the head mechanic at the marina, and he spotted it right away. Cold water intake keeping the resistor too cold, therefore not heating up and limiting the current to the coil :facepalm:

So just a tip, external resistors need to heat up in order to work properly, don't attach to cold water line (only someone dumb us would do it in the first place)

Hello I been waiting for someone to respond to my post, coil wire related post. My coil gets pretty darn hot too. Not using a resistor. Did you just install a automotive ballast resistor? Did you protect the wiring terminals some how, or not necessary?my boat somebody removed a starter selonoid and is feeding starter with yellow/red wire from harness. Could you give me a run down how you wired it up. My one side of the coil has a combo purple/black with red/black looks like. One of these would or should have the factory resistor but I did not tear open the harness. I am running a 2.3l what motor u have?
Thanks so much for any info
Glad you found a fix for your problem! I carry a spare coil and points with me. Ya never know!

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

this is a 2.5L 1986 model 400 out-drive. the resistor should be between the alternator and the positive side of the coil. Mine had a resistor wire that was spliced and generally a mess, so got a standard coil with automotive style ballast resistor, just used the included crimp on connectors.

there should be a wire from the starter solenoid to the positive side of the coil as well, withOUT a resistor. This is to feed the coil while cranking the engine, that wire is dead once you stop cranking the starter.

on the negative side of the coil you will have a few leads , one for RPM tach, one feeding a shift interrupter system (if your boat has it) and one to the distributor

I did not cover the connectors on the resistor, which is what made us zip tie it to the raw water intake line..needless to say that kept the resistor from heating up and, well, becoming resistive like it should.

 

[Howard Sterndrive]

Re: Ballast Resistor Mounting...a quick tip

the odd thing to me is that all the cars I saw driving around northern Canada in the 70's had ballast resistors and they worked fine at -40 degree ambient. They'd be mounted on a fender or something way colder than your water line. And every time you'd blast through a snowdrift they'd get hit with snow.

Makes me think you may have went a touch too low on the resistance if the ballast is requiring it's own heat to develop enough ohms to drop the coil V.
You might want to carry a spare coil and points. If the coil got hot enough to cause rough running, it may be hurtin'.
Easy enough to check the V at coil + (referncing batt neg)
I had mine mounted on the exhaust riser. Then I switched to an internally resisted coil and hooked B+ to it.

 

[jerryjerry05]

Re: Ballast Resistor Mounting...a quick tip

Chris,Just replace with a coil with an internal resistor.
Or go to someplace that sells Volvo/Chrysler IB parts and get the inline resistor.

 

[projo198]

Re: Ballast Resistor Mounting...a quick tip

Do you have a link or other information about the resistor you used?

I am wanting to do this as well, and know many people have, but no one can elaborate on exactly what kind of resistor to get.

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

Just go to the parts store and ask for an ignition coil resistor. Got mine at napa here in canada. Came in a little box with no information regarding resistance values or wattage...its just universal. Its ceramic with two connectors and a mounting hole.

Regarding the cold temps and snow, my thinking was the same..how can a water line be colder than a canadian winter? I guess,as it turns out, a cold water line is very good at thermal transfer, kind of like when you throw a plastic water bottle in a fire...it doesn't melt or leak for quite a while.

 

[projo198]

Re: Ballast Resistor Mounting...a quick tip

Just go to the parts store and ask for an ignition coil resistor. Got mine at napa here in canada. Came in a little box with no information regarding resistance values or wattage...its just universal. Its ceramic with two connectors and a mounting hole.

Regarding the cold temps and snow, my thinking was the same..how can a water line be colder than a canadian winter? I guess,as it turns out, a cold water line is very good at thermal transfer, kind of like when you throw a plastic water bottle in a fire...it doesn't melt or leak for quite a while.

Ok, thanks for coming back to this.

This is what I was looking at, I was just concerned because I believe they all push out 6V when we are supposed to be getting 8-9V at the ignition coil.
http://www.oreillyauto.com/site/c/d...ck=Search_02773_1326293_-1&pt=02773&ppt=C0334

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

that resistor is identical to the one I got, although mine doesn't have the BWD brand, I think its a mass produced item. Not sure what the output voltage is on my resistor. Make sure you don't use a resistor wire + ballast resistor, then you will definitely have low voltage to the coil.

 

[jerryjerry05]

Re: Ballast Resistor Mounting...a quick tip

That resistor is the same as Chrysler/Volvo.Just put 12 v in and measure the output.
They can go bad and be bad right out of the box??

 

[Grandad]

Re: Ballast Resistor Mounting...a quick tip

OK, I bit my tongue til it bleeds, and I still have to ask: Why would someone want to replace a functional resistance wire with an equivalent resistance ballast resistor? I've had to replace 2 of these ballast resistors in cars that let me down when they failed. Got a towing charge and parking ticket the first time it happened at an inconvenient time and place. No place on the water is convenient. Automakers replaced the ballast resistors with a resistance wire to avoid these failures. No hot spots to worry about, either. Has someone established that the engine manufacturers made a mistake when they changed their designs? - Grandad

 

[Howard Sterndrive]

Re: Ballast Resistor Mounting...a quick tip

I was wondering why people don't just get an internally resisted coil and make it all that much simpler... the resistance is just built into the coil primary. The hotter starting spark of the ballasted system was designed for winter starting and most of us don't start our boats in the winter.

I got mine at TSC - they have 2 on the shelf - internal resistor and external resistor. I just chose the internally resisted and threw the ballast resistor in the garbage, and also eliminated the bypass wire to the R starter terminal. Makes the whole thing simpler. I did the same conversion on my old Volvo 122.
And safer in my opinion. Those ceramic housed resistors get bloody hot.

One mistake people can make when choosing a ballast resistor is to measure the ohms cold and assume that will be the value in the circuit. At temperature the resistance can almost double. Need to measure amps and voltage drops and use ohms law if one wants to know resistance value while in operation. Same idea as light bulbs- cold resistance is not hot resistance.

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

Internally resisted would be simpler, and my thinking was that if the internal resistor went bad, then the whole coil is bad..but if what howard sterndrive said is true then there isn't necessarily a resistor in those coils, its just part of the primary winding in the coil making it a more reliable option.

In my case, I had 2 coils break down in 1 year (1 last season, and one this spring) , I realized that over the years the resistance wire was spliced and bypassed and who knows what else...usually resistor wires are pre-cut and sold with a P/N at the marina, not just off the roll. Unfortunately OMC parts are difficult to cross reference these days so I just grabbed a standard coil and a coil resistor from the auto parts store. For some reason, standard coils are easy to find for around $40 here in southern Ontario, but I could not find any internally resisted coils. If I were to order one, it would be $90 so I decided against internally resisted coils.

 

[projo198]

Re: Ballast Resistor Mounting...a quick tip

well I bought the ceramic resistor from the parts store and tested it from the battery. It was supposed to be the right specs but I tested it on the battery and it let 12v go through no problems.

Checked a lot of my wiring and I'm gonna stick with the original resistor wire for now I guess, until I find a better solution. I'm getting anywhere between 7 and 10v at the coil with it running so not too bad.

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

well I bought the ceramic resistor from the parts store and tested it from the battery. It was supposed to be the right specs but I tested it on the battery and it let 12v go through no problems.

Checked a lot of my wiring and I'm gonna stick with the original resistor wire for now I guess, until I find a better solution. I'm getting anywhere between 7 and 10v at the coil with it running so not too bad.

sounds right...without load there will be full voltage through a ballast resistor, only when load is applied does the voltage begin to drop (hence, when the points are OPEN there will be 12 V at coil, when closed it will fall to 8-9 V)

 

[projo198]

Re: Ballast Resistor Mounting...a quick tip

Oh I see. I didn't have it under load. I was gonna take it back, maybe I'll hold onto it in case I can utilize it in the future.

 

[Howard Sterndrive]

Re: Ballast Resistor Mounting...a quick tip

For some reason, standard coils are easy to find for around $40 here in southern Ontario, but I could not find any internally resisted coils. If I were to order one, it would be $90 so I decided against internally resisted coils.

Store Locator
http://www.tscstores.com/Coil-12-Volt-P2733.aspx

 

[nick_vw]

Re: Ballast Resistor Mounting...a quick tip

amazing, I live in midland (one of those towns without a TSC store) so I never would have guessed. I just did NAPA after seeing the inflated prices at the marina. I think ill be making the trip to TSC stores more often

 

[projo198]

Re: Ballast Resistor Mounting...a quick tip

Yep, that's where I found the wheel bearing kit for my boat trailer this week. only after going to 3 different parts stores.

 

[bruceb58]

Re: Ballast Resistor Mounting...a quick tip

A power resistor is not going to change resistance significantly when its hot or cold. Not sure what happened when your friend moved it off the water hose but it wasn't because of the temperature.

The reason you want to use a coil with an external resistor is so that at start, you can bypass the ballast resistor to get a higher voltage to the coil. The problem with the internal ballast coil is that you will get a much lower voltage while the engine is cranking.