1968 W115 220 Starter problem possible cause

[marlin]

My starter seemed to have intermittent failure over the last three weeks . Same problem with a Fiat years ago . Good Bat + Grounds . I'm getting 12-13V at the Bat and the Starter posi terminal . But no voltage at the lower terminal . Purple wire on W115 . That's with the key cranked all clockwise . No voltage . My very first thought was the ignition switch . The Fiat had contact problems from the ig switch to harness . I removed the plastic terminal clips . Soldered the wires , tossed the clips and it worked . Soooooooooo I'm going to buy a ignition switch and give it a shot . What do you think ? Alot of people don't agree with my idea . But there's not much to rule out between the key and a good starter . I sure hope so !!!!!! Let me know your opinion .

[Mike D]

I've had a couple of ignition switches come apart. The crimps fail and the switch spreads to the point where it doesn't make contact in the "start" position but does at the "run" due to wider contacts.

I'd check the wiring harness to ensure the NSS jumper is in place. On the LH frame rail, in front of the master cylinder.

[CTD]

Does the starter turn when you connect its solenoid to a live 12-volt power source?

[marlin]

Originally Posted by CTD

Does the starter turn when you connect its solenoid to a live 12-volt power source?

The starter in there is new . I personally did not test it . I don't know if a screwdriver test would work . Can I jump to the Solenoid live while the starter is installed .

[marlin]

Originally Posted by Mike D

I've had a couple of ignition switches come apart. The crimps fail and the switch spreads to the point where it doesn't make contact in the "start" position but does at the "run" due to wider contacts.

I'd check the wiring harness to ensure the NSS jumper is in place. On the LH frame rail, in front of the master cylinder.

Is NSS the contact plug on the LH Inner fender ? I did clean that one up . Also that's a good idea . On the female harness which connects to the back of the ig switch . I will try crimping in the female clips a little . Good idea .

[Mike D]

If you've got the instrument cluster out try touching a 12V lead to the "start" circuit wire at the switch end. If the starter engages you will at least have eliminated the bit of wiring between the switch and solenoid as the culprit.

The crimp I am referring is on the actual switch not the connector. There are four or five crimped "ears" holding the plastic portion of the switch to the metal body.