merc 115hp mod 1150 thunderbolt ign.

[wbeckelman]

With ignition off, but battery connected I inadvertantly shorted two of the contacts together with a screw driver on the "switch box assembly".
I'm not real good with outboards but I believe the switch box assembly contains ignition circitry . the wiring diagram I downloaded does not show the internal diagram or any componants for the switch box assembly.
what test can I perform to determine any damage I may have caused and what to do to correct the problem.
Before this happened the engine started quite easily. not so now.
any info about this box would be helpful.
Bill

 

[Dave1027]

Re: merc 115hp mod 1150 thunderbolt ign.

Use a DVA and voltmeter to diagnose ignition problems.

 

[Gomer50]

Re: merc 115hp mod 1150 thunderbolt ign.

Courtesy of another member here,if this applies to your switchbox this test will tell you if your good to go or you are in need of another switchbox.Good Luck.These things dont come cheap...
MERCURY BATTERY-POWERED CDI TEST FOR DISTRIBUTOR MODELS

This test is for the 332-2986 switchbox used from 1967-1978 on all the inlines.

This test assumes your coil is good (problems with CDI coils are rare).

DISCONNECT BATTERY

1. Turn off ignition;

2. Disconnect all 3 distributor wires on the Port side of the switchbox (and the ?mercury switch? if present);

3. Remove the High Voltage lead from the ign coil to the center of the dist. cap (remember it unplugs from the coil and unscrews from the cap);

4. Reconnect the H.V. lead to the COIL only;

5. Position the free end of the HV lead approx. 3/8" from ground (block, shrouds etc), and find a way to hold it there;

6. Jumper the brown and white terminals on the distributor side of the switchbox to each other.

RECONNECT BATTERY

7. Check that you have +12V at the red terminal (even with the ign off);

8. Turn on ignition and verify +12V at the white terminal (same side as the red terminal);

9. Ground the black terminal on the distributor side of the switchbox - this should cause a spark each time you touch ground.

If you get spark with the distributor bypassed, and it won't fire with the distributor connected, the trigger is bad and the entire distributor housing assy must be replaced.

If you get no spark using the test, the switchbox is probably bad. In that case, be sure to check for correct power on the switchbox, check all connections, and check the coil's resistance to make sure it's OK."