Wiring experts needed....

[JimG]

BigGrizzly, Scott Pearson, etc. I need help!

Still sorting this thing out. BigGrizzly, you said something a while back about the ignition circuit running through the old-style tach? I've got a red(green stripe) wire that was connected to the old Holman Moody tach. It runs to the engine compartment and terminates on one end of the ceramic ballast resistor. On the other end of the resistor are two wires: a green one runs to the solenoid and a red one to the coil. When I hook the red(green) wire to hot(ignition), the ceramic ballast gets hot to the touch(not good, I think). When I put a meter on it I've got 12v going in and 5v coming out. Is this normal? Or a bad resistor. (The solenoid will not fire now, but it's only getting five volts.)It also backfeeds into the lights (the lights will come on even if the key is off.

I'm thinking the resistor is bad. What do you guys think? Should the wire from the old tach be hooked to ignition, or am I screwing up? I'm not too good on old wiring yet, but I'm learning!!

Thanks a ton!

JimG

[RawHide]

Jim, on the old tachs, you should have 4 connection points. One (BAT) will go to the battery or a hot terminal perferably through the ign switch. Another (SND)will go to the coil (-side). The one from the light will go to the light switch. The 4th will be for your ground. Make sure you have a good ground wire all the way to the battery. This is where the back feed is probably coming from.
E-mail me if you need more info. (stuchamp)

[RawHide]

Your resistor is probably ok, a drop from 12v to 6-9v would be normal. If checking with ohms, disconnect the battery ground and then connect the meter between the coil + and - posts. If you have a reading of 1.30 to 1.45 ohms, the resistor is ok. If not certain, replace it with a new one.

Refer to the diagram that I sent you earlier for the basic starter & ign wiring.

[JimG]

Thanks Rawhide!
Ok, so the resistor's OK. I'll pick up a new solenoid today. (The right one hopefully!)

My wiring doesn't jibe exactly with your diagram. One of the wires coming out of my old tach was a red/green. It connects to one side of the resistor. I guess this is how the coil gets its power. I connected it to the IGNITION side of my switch last night. (I had installed a new tach.) Still no worky, but now I'm suspecting the solenoid. It won't throw at all now.

Thanks!! JimG

<small>[ March 11, 2003, 07:55 AM: Message edited by: JimG ]</small>

[RawHide]

Jim, for now I would leave the tach unhooked. Get your basic wiring working so you can start and stop the engine, then go back and add in your accessories, tach, etc.
If the boat still has the original wiring, you might want to consider replacing all of it.

[boatnut]

Looking back at your original post and the ongoing saga I would guess you have created or at least are experiencing more than one fault in this ignition circuit. Originally you had the solenoid working and the engine starting but it would quit when you released the key to the run position --- this is (almost) always caused by either the ballast resistor or the key switch.
(the key switch provides power to the ignition in run through different contacts than it does when the starter is engaged) You have since swapped lots of parts and wiring connections maybe creating a difficult to analyze set of symptoms.
I think you have proven if I read correctly that the ballast resistor is working.
Have you ever carefully tested or replaced the ignition switch? As others have suggested, you may have created a situation that now requires rewiring the entire ignition circuit. This is fairly easy but be careful about "trying" different wires in different positions as you may have been doing and then powering the circuits or you will continue to create new problems and short out things etc. Also keep in mind that a neutral switch may be in one of these circuits to keep someone from starting the boat in gear. Good luck, view this as fun.

[JimG]

Thanks Boatnut!

It IS fun!

The tach is unhooked now. The ballast resistor appears to be working. Can anyone verify the red/green from the tach to the resistor? Is this how the coil gets it's juice?

The switch is new. I've got a spare, and tried that too.

Thanks!

JimG

[BigGrizzly]

When the tach is bad just hook a JUMPER WITH ALLagator clips to the resistor to the positive cable the engine shoukld start and tach will probably be bad.The other pole on the Ford solinoid is just to jump the resistor. That tach isn't like the old tachs in autos. the power runs through the tach. No tach no power to coil!

[JimG]

BigGrizzly, I replaced my tach with a new one. (Not hooked up currently) Should the red/green (out of the tach running back to the resistor)be hooked to the ignition side of my keyswitch?

<small>[ March 11, 2003, 04:29 PM: Message edited by: JimG ]</small>