electrical question on 1992 3.0

[nhcris]

So I just installed new plugs, cap and rotor on our boat, Launched it into the lake on Sunday and it ran beautiful. We ran it for 3-4 hours without a hiccup, and then it started going downhill from there... It would run ok until I hit the next bump, it felt like it had bad gas or was losing spark in a cylinder or two. I limped it back to the launch and backed the trailer in, when my wife went to restart the boat it was dead. My friend in the boat with her looked at the battery and found the negative cable loop had snapped off the battery post, he held it on while she started the boat and got it on the trailer. Yesterday I replaced both battery cables so I dont have that problem again...Question is, would that cause a runnability issue? Shouldn't the alternater be providing all the power it needs? Or is it something that the hei needs power for? Any ideas if I should be looking for other problems?

 

[Kainon]

Re: electrical question on 1992 3.0

you should be able to run without the battery, never tried it on a boat though I have on my '69 Car. Good way to Check the Alt.

SO with the engine running should have 13.5V at the battery with all connection clean and tight. I would add Nylock nuts and Toothed washers ( not lock ) to the battery connections. You may also either need to replace the cables or just the ends. I like to solder new ends on.

 

[cr2k]

Re: electrical question on 1992 3.0

So Kainon did you read that he did replace both cables?
If your cable end was sparking as it was breaking it very well have blown the diodes in your alt. there by rendering it usless and you would have no electricity to power the boat or the shorting feedback could interfere with in ignition.

 

[nhcris]

Re: electrical question on 1992 3.0

The old negative cable looked like it had arced a few times. The boat never stalled but it did stumble pretty hard. I would try running it on the muffs but it seemed to idle fine. I really don't want to dump it in the lake to find out....

 

[Don S]

Re: electrical question on 1992 3.0

DO NOT disconnect the battery cables on a running engine. That is a sure way of blowing the diodes out of the alternator.
It also doesn't test anything.
Hook your new cables up using regular nuts (NO wingnuts). Then, if you didn't damage anything when the cable came loose, you should be good to go. You have electronic ignition, without a good ground, you don't have anything for the electronic distributor to work with.

Run it on muffs before heading to the lake.

 

[nhcris]

Re: electrical question on 1992 3.0

Thanks Don, thats what I thought with the electronic ignition. Is it safe to run it for a while on the muffs above idle?

 

[Don S]

Re: electrical question on 1992 3.0

Just keep it under 1500 rpm. Biggest problem is getting enough water for cooling. If it runs ok, then put it in the water and run it up. At least on muffs you can check the alternator to make sure it's Ok, and if the engine is smooth, it should be fine in the water too.