No spark

[cwehralaska]

We have a 1991 SeaSport Pilot with a Volvo 740A carbed engine and a 290DP drive. Last fall, due to a noise in the bell housing, we took in to be worked on (turned out to be a good thing, the "Y" was shot and we ended up replacing manifolds & risers, too). At the same time we replaced out fuel tanks and we're just now getting everything back together. Apparently, while our mechanic might be a good mechanic, he's no electrician! After tracing numerous wires and grounding many circuits that were left loose and fixing things we didn't even know were broke, I've run out of wires to try! There just isn't any spark. The starter runs fine but there isn't power to either side of the coil or to the electric choke.. The neutral switch seem okay. Does anyone have any other place to look? The weekend is going to pass us by.......

Carolyn

 

[cwehralaska]

Re: No spark

Just wanted to add- there is voltage at the breakers- both sides.

Carolyn

 

[Don S]

Re: No spark

Start at the ignition switch, turn the key to run, and track the power on the ignition wire (purple) from the switch to the + terminal of the coil.
The 740's usually had a fuse for the ignition at the helm someplace.

 

[cwehralaska]

Re: No spark

Don- Thanks for the quick reply!! I went out and I have voltage from the ignition switch to the connector behind the 50 amp breakers. From there, the wire becomes two purple wires. One goes into the main wiring loom to the + terminal of the coil and the other goes to what my wiring diagram calls the "speed limiter" on the transom. The grey wires that are on the - terminal also split, one going to the loom and then the tach, the other going to the "speed limiter". I don't know what the speed limiter is (maybe a rev limiter) but could that go bad?

Carolyn

 

[Bondo]

Re: No spark

From there, the wire becomes two purple wires. One goes into the main wiring loom to the + terminal of the coil and the other goes to what my wiring diagram calls the "speed limiter" on the transom.

Do these Purple wires show 12V,..??.....

 

[Don S]

Re: No spark

First of all, the purple wires should NOT be hooked to that circuit breaker at all.
Click Here for a wiring diagram of your 740. I touched up the wire colors to make it easier to see where things actually go.
The red wire starts at the starter to the breaker, then to the ignition switch. When you turn the switch to the run position, then you have power to the purple wire which goes to the choke, and the coil and to the rev limiter.
Yes you can disconnect the rev limiter to test.

 

[cwehralaska]

Re: No spark

Don,

Thank you for the diagram- I'm going to go out and see if I can straighten this mess out. I do have one more question, though. Does the plug to the main wiring connection come apart? It looks like it should, it's a round, rubber plug that seems to come apart but I haven't had any luck and I sure don't want to mess up anything else!

Carolyn

 

[cwehralaska]

Re: No spark

Don- I checked everything against the wiring diagram and as near as I can tell, I'm missing one purple wire. I lose it after it goes into the main wiring cable. On the + terminal of the coil there are only two purple wires- one to the rev limiter and one to the choke. Do you have any idea where the other one should come out of the cable?

Carolyn

 

[cwehralaska]

Re: No spark

Don-

I found the problem- the purple wire was not carrying current through the connector. Should be fixed by this afternoon. Thank you again for the diagram- I found a couple more disconnected wires!

Carolyn