79 evinrude tilt relay troubles

[78mfg79evinrude115]

Hello,
have 78 mfg w/79 evinrude115..When i got her the tilt unit was out of the boat, fixed pump motor and tested, worked great.. put it back on boat and goes up but not down..swapped relays..goes down but not up. So i figure no prob, bad relay. Buy new one, install, connect neg battery cable, relay box starts smoking like crazy nearly caught on fire but luckily disconnected quick enough(some melting did happen obviously but got to dark to work so i wont know what until tomorrow). I realize a few possible causes right in the junction block(connections arching together), but what are some other things to check..and what possible damage was done.. I am a complete newbie to boating, this boat was bought for $1, been trained auto tech for 16 years and have enough electrical knowledge to get me by in the garage. Any help is much appreciated...

 

[78mfg79evinrude115]

Re: 79 evinrude tilt relay troubles

should prob add the manual says 3 wire system for 79 115, mine 2 wire..tag says 115993R on motor.. must be hybrid of sorts

 

[emdsapmgr]

Re: 79 evinrude tilt relay troubles

Your model number says 1979. The 79 models came standard with a 3-wire trim motor and a special junction box which mounted remotely under the rear splashwell of the boat. It had it's own cables connected direct to the battery. The single solenoid inside controlled the up movement. The down movement current goes through the switch on the control box handle only. The factory glued the wiring diagram inside that control box cover. Newer 2-wire trim motors use a different trim box which mounts at the back of the engine exhaust cover and uses two interchangeable relays. If the engine goes up but not down, you can swap the relays. It should go down but not up. Buy a new pair of relays and install both, keep the good one as a spare. These different systems are not compatible with each other. You need to make sure you have the right components to go with the number of wires on the trim motor. You can match your parts with the original factory parts list on the web at epc.brp.com

 

[78mfg79evinrude115]

Re: 79 evinrude tilt relay troubles

yes i can see in the manual that the 79 is 3 wire, i must have newer tilt unit, 2 wire ...there is no solenoid just relay box mounted inside the boat..but in the day light i can see that the smoking wires are destroyed...upon further inspection the rest of the wiring is a nightmare...spaghetti and electrical tape everywhere..the tach doesnt work..but the temp gauge does..i am going to get a new relay box and some new gauges, and remove the rest of the wiring from the boat.. for now i cleaned some spaghetti up and will just touch wires to the battery to activate tilt motor until new parts come in..but not a penny more until i get it in the water and can be sure all is sound and safe for my family-aside from the wiring, as i said i paid a dollar for it and dont mind my labor time and some money but i dont want to get in over my head until i know how well the motor runs on the open water...sound great in the driveway on the hose..to any one interested i will post after the test run this weekend..wish me luck

 

[emdsapmgr]

Re: 79 evinrude tilt relay troubles

A converted 2 wire system should work fine. If you have a factory 79 service manual, it won't be of much help. Any OMC service manual from midyear 1981 and later will have a 2 wire electrical diagram in the back of the book that should apply to your trim system.

 

[78mfg79evinrude115]

Re: 79 evinrude tilt relay troubles

yes i think i have the proper 2 wire diagram but now i have the issue of melted female relay plug and wires... i have been searching but cant seem to find just 1 relay plug and attaching wires, seems to be a couple used relay boxes on ebay prob grab one of those clean real well and start fresh... thanks for the help

 

[emdsapmgr]

Re: 79 evinrude tilt relay troubles

You may also have luck finding complete used relay boxes at marine salvage yards. They are pretty common and you should be able to find a suitable replacement in good condition.