SyberTiger

I'm trying to diagnose an intermittent start issue with my girlfriends 1998 Chevy Blazer she has owned since new.

The problem is, that on occasion, when she turns the key to engage the starter it does not crank. On other occasions the starter engages and the vehicle starts up like you would expect. It is just about impossible to figure out why sometimes the vehicle starts and other times the starter will not even attempt to engage. The battery is fully charged, the starter is about one year old, when the starter does kick in it sounds normal...no hesitation, no clicking...it sounds good and strong and the engine fires up quick.

When the problem does occur, the vehicle may have been started up five times that day but on that sixth time coming out of the grocery store with ice and a box of ice cream or in a hurry that will be the time the starter doesn't engage. Basically, when the key switch is turned to the run position everything looks normal...lights, gauges, radio, and everything you would expect to function when the key is in the run position. However, when you turn the key further to engage the starter it does not crank like you never even tried to engage the starter.

For now, my theory is that it is the starter relay which sits in the fuse box under the hood. There is an identical type relay (maybe for the defrost system?) and I have swapped the two in an attempt to determine if the problem is a dying starter relay. I can tell you that four months ago this startup/crank problem was happening once every few days and was getting worse so I swapped the two relays mentioned above and it would appear the crank problem went away implying the problem WAS THE RELAY. Now four months later the problem is back.

Because the problem comes and goes it is difficult to diagnose. My question are...Has anyone in this forum experienced this problem? What are the symptoms of a relay going out? How do you diagnose exacting where the electrical problem is occurring? What else is in the start circuit could be failing which would give intermittent cranking problems.

To add to this story I also want to mention that my girlfriend about 5 months ago, because the vehicle would not crank, had the Blazer towed to the mechanic who had 6 months prior installed a new starter. The vehicle sat in the mechanics lot on a Sunday evening and on Monday when the mechanic went to check up on the problem the vehicle started right up so there wasn't anything for him to diagnose. I know that on several occasions where the girlfriend abandoned the Blazer because it would not crank but came back the next day the vehicle cranked right up. Again, the problem I am trying to solve is why sometimes the starter will not engage and other times it will. When it does not engage there is no sound, clicking, popping, etc. but rather it is like you never even attempted to turn the key past the normal run position in the key switch. I should also note that trying to jump start the Blazer using jumper cables does absolutely nothing to resolve the issue.

Another mechanic my girlfriend uses went through the entire system including verifying all connections where tight could not find a thing because as you would guess the Blazer would crank while they had it.

Perhaps, I should have the girlfriend but a new starter relay for $20 at Autozone then see if the problem goes away. I don't know but I hate like hell just swapping out parts until the failed component is found.

tim_cleav

Take an old pair of booster cables and tear them apart.. take the black one and cut the ends off and make a new ground cable out of it by putting connection ends on it. run it directly from the battery to the bolt that holds the starter onto the engine. it will fix your problem. its not a relay. I had the same problem and spent 1000 dollars in the shop and I got no where, next thing I know a buddy of mine with an old pair of booster cables he fixed the problem in under 20 mins !

SyberTiger

I'm wondering if your buddy had an explanation as to what is going on as this is an intermittent problem. That is, about one out of 20 or 30 attempts to engage the starter nothing happens but all the other times the vehicle starter activates just fine. Any plausible explanation would be helpful in understanding what has deteriorated over the years.

tim_cleav

mine was the same way! it would crank one time and not the next.. I would put money on it being the ground cable.. all the lights and instrument cluster will light up fine too, because they don't require the power the starter does..

I asked my friend about your specific case however and he says to check the cables at the battery and the starter for corrosion and file the connections!

edac

They have a history of bad ignition switches, how much junk do you have on your key ring?