View Single Post
Old 10-07-2014   #10
Paul Workman
 
Paul Workman's Avatar
 
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
Default Re: Intermittent issue starting the car , VATS or starter problem? ---

Quote:
Originally Posted by alwayscode390 View Post
So the clutch safety switch is depressed with the pedal , like the brake switch right?
No. Just the opposite.


Quote:
Originally Posted by alwayscode390 View Post
I may have tried starting it too quickly , the link Lee shared above stated that you should never try to start and push the clutch at the same time ... I will be more mindful of this from now on.

Thanks! ---
The clutch (interlock) safety switch operates like the door (courtesy light) switch. When pressure (on the plunger) is released (as the clutch peddle is pressed) the switch closes and completes the circuit to the starter (on the 90-92s).



For 93 thru 95s the relatively high current is re-routed so that the start current by-passes the clutch pedal switch, significantly reducing clutch switch failing significantly...



Note: The (above) diagrams courtesy of Mark Haibeck's article from Heart Of The Beast).


Just this past week, I too experienced that clutch safety switch failing. This was in spite of being mindful to depress the clutch pedal completely before turning the ignition switch. The problem was foretold by the starting becoming "sketchy" (intermittent). For verification, I temporarily bypassed the switch, and now there is ZERO hesitation or erratic starting as I noted up to the time the switch finally did fail completely.

Here is a bypass circuit I designed to alleviate the load on the clutch switch for the 90-92 MY cars; moving the load to a more accessible, plug-in relay.



Of course simply by-passing (eliminating) the clutch safety switch eliminates the problem, and this aux. relay (above) would not be needed; so why bother?

Pros and Cons of keeping the switch:

Pro:

Safety. The car will not start unless the clutch is depressed.

Con:

1) The car can be started without having to climb into the drivers seat and depress the clutch. This is convenient in many situations.
2) It is possible to move the car a (very) short distance by rolling the starter alone should the engine be dead (for example).

fWIW,

Paul.
__________________
Good carz, good food, good friendz = the best of timez!

90 #1202
"FBI" top end ported & relieved
Cam timing by "Pete the Greek"
Sans secondaries
Chip & dyno tuning by Haibeck Automotive
SW headers, X-pipe, MF muffs

Former Secretary, ZR-1 Net Registry
Paul Workman is offline   Reply With Quote