115 hp evinrude rectifier replacement 1979

[woolsac]

i purchased a cdi 153-3408 rectifier recently which was recommend for replacement. it came and it had a red wire and 2 yellow wires. the one i have currently that needs replacing has a red wire, yellow wire and yellow/gray wire. does anyone know how to figure out which yellow wire on the new one matches the yellow/gray wire on the old one?

i think that i may need to send this back, but not sure if i have to ask for the specific wire color scheme when ordering this part?

thanks!

[ezeke]

It does not matter which of the yellow wires goes to the corresponding yellow & yellow and gray posts.

[bigtexnick]

wool, i have a 1978 evinrude 115hp, maybe i can see how mine is wired and send pics to you, let me know if i can help. honestly i dont know much about engines/electronics but i'm about to replace my water pump in a couple days..... keep in touch, since we have similar motors --nick

[david_r]

ive got a '79 johnny 115 and i had to look real close at the wires but the wires coming in from stator and the new rec were also marked with the yellow and yellow/gray.

i just unhooked the wires without thinking about the placement but my wires were marked.

i would listen to ezeke ive been reading the threads for a while and he knows his stuff.

[woolsac]

Thanks for the help all. This cdi part has been identified to replace the bad rectifier i have currently. i was shocked to see that it did not have the same color scheme as the one that needs to be replaced. It looks like ezeke knows his stuff, so i will take his word for it. i will hook up the red with red, and whatever yellow wire on the new one with the yellow and yellow/gray wire.

my trouble was that my tach was not working. i read the forums and saw that problems usually lie with a bad rectifier. before installing the replacement, the tach all of a sudden started to work fine. the next test i ran was to see if i was getting a charge on my battery when running above 3500rpm. i did not see any charge imposed on the battery.

the next test i ran was a diode check on the rectifier and i believe i uncovered the problem there. i had a lead to ground and the other to the yellow. one way i had high ohm reading, then with switching the leads I had a low ohm reading. then, i tried this test on the ground to yellow/gray wire and got no readings at all each way. and the same thing when connecting the leads between yellow and yellow/gray.

so i think that backs up the rectifier being bad. any thoughts?

nick - thanks for the offer. i will hook this up and if i have any problems, i will get in touch about pix. let me know how you waterpump replacement works out. i will probably have to do that too at somepoint, maybe over the winter....

[Xcusme]

so i think that backs up the rectifier being bad. any thoughts?

Yup, it's toast....if you're reading open circuit in both directions...

Install new rectifier, place Red lead as original. The remaining 2 wires are A/C voltage from under flywheel stator, and should not make a difference which way they are connected.
The rectifier's input is the 2 wires from the stator (A/C voltage) . The rectifier Output, is the Red wire (DC voltage) which can vary with motor RPM's.

[Vic.S]

so i think that backs up the rectifier being bad

yes it does. BUT you have only tested half of the rectifier. You should also have done the same test between the red wire and the yellows. however you did enough on this occasion to prove that it is faulty.

You will get no reading between the two yellows with a good rectifier.

When you have fitted your new rectifier be absolutely sure that you never connect the battery with the wrong polarity. The new rectifier will be toasted instantly if you do!
Also disconnecting the battery while the engine is running may damage the rectifier, important therefore to avoid poor connections!

[woolsac]

replaced it and everything works great! got a charge on the battery when runnning and tach still works too. thanks everyone for the very useful info.

[bigtexnick]

wool, congrats on getting it fixed!.... water pump replacement was a bit of a headache, but we got it done and replaced and hopefully solved the overheat alarm problem. here are some pics. http://texasfishingforum.com/forums/...ooding_problem (this is a great site for advice and troubleshooting)

[david_r]

sorry i should have mentioned about the better rectifier/regulator sooner but wasnt for sure what to say since i didnt know all the info till today(or if it was even possible) and didnt want to confuse the situation with my own questions.

it might be of intrest to bigtexnick and woolsac.

its best explained in my thread..... ezeke helped fill me in after i fried my rectifier:

http://forums.iboats.com/johnson-evinrude-outboards/79-johnson-115-rectefier-277036.html

it is a little more expensive though.

i think we have about the same motor other than the name.

again sorry about not mentioning that i thought there was a better alternative