I have a 94 Blazer Sport that has a periodic starting problem. When turning the key to the first position (dash lights, etc.) going to the second position sometimes starts the truck & sometimes it won't start. Nothing, does not turn over or make any sounds (click). Like I said this is a periodic problem it doesn'thappen all the time although it seams to be happening more frequently. Brought it in to be checked & they couldn't replicate the problem. Starters good so I think it sounds like some kind of relay...not sure if there's one for starting? I see an optional relay & fuel relay under the hood. If anyone has had this happen I would appricate any input.Thanks.

 

I would suspect an ignition switch problem. I know it is a fault of many s-series vehicles, but not sure of how prevalent it is on the fullsize trucks.

 

I appricate the quick response. As a new member reading about ignition problems others have experienced & your input has help me. I was wondering if you know what the optional relay is for? Somehow I feel it's for more than just options. Would you have a print of the electrical starting system I could look at so I can get a better understanding of the control circuit. Once again thanks for the help.

 

You have to be more specific. There are many different diagrams for your vehicle and I cannot find and post them all for you. I also cannot find information on this "optional" relay you speak of.

 

Thanks for getting back to me. On my 94 Blazer Sport engine compartment right rear wall there's a terminal relay cover that reads "GND, Fuel Pump Relay, Optional Relay, & GND. Removal of the cover revealed the two relays and a four lug terminal board however I can't find anything on the Op,relay.
I guess I'm looking for a schematic of the starting circuit that would include a start relay and/or the optional relay. Once again I appreciate your assistance.