Starter or starter relay

I am having the same starting / starter failing/grinding problem that I had back in 2015 when I had a harness and relay added between the battery and the starter as part of a recall. The added relay was a 4-pin Omron 12177235. I have two questions. Can I swap another 4-pin relay from say, the cooling fan - to test and see if it makes any difference and/or can I use a wire to connect 30 and 87 on the relay connection pins to do the same thing - so that I can know if it is the starter or the relay? I am stuck in a situation where I cannot use a meter to test the relay off the car so that won’t help.


Yes you can, as long as the plug is compatible. Those things are inexpensive, less than $10.

Update: I took out the relay from the starter harness, tested the connections using a wire from 30 to 87 - same result as with the relay that was in there. Swapped the cooling fan relay into the starter relay location - stared right up 5 times like new, no problems. Thought the problem was fixed - went for a drive around to make sure nothing funky happened, and to charge up the battery. Started fine 3 or 4 more times - so went to bed thinking all I needed to do was make a quick stop by the parts store for a new starter relay. Got up, turned the key - back to square 1. Same no-start / grinding / scraping hell sound. I just don’t get it. Very upsetting and disappointing. The connection/plug that the starter relay fits into has 4 pins - the same as the cooling fan relay. The difference is that the cooling fan one is from the regular fuse box and a small cube-shaped relay, whereas the starter relay that fits into the end of an added wire harness is much larger - because of a big plastic hood/housing that covers the plug and screws into the radiator support. The other thing is that the starter relay that was in there was a 5-pin but the 5th pin - in the middle that doesn’t go into anything (no metal connection, just fits into a blank hole in the plastic) labelled 87A was present. That is not in the 4-pin cooling fan relay. Figured since it didn’t plug into anything in the wire harness, that it wouldn’t matter. Am I wrong?

I am at a loss. I had recently been having a problem with loose/stripped negative battery bolt but felt and examined that during this whole situation many times and it appears nice and tight/snug so I don’t think that is related. I just don’t get it.

Do you like just being miserable ? This worn out vehicle needs to be put in a shop and fixed or you need to replace it before it fails in front of a semi truck .

Right on time. Like the sun coming up in the morning. You are nothing if not predictable.


No relay is going to make your starter grind… it could either make the starter not engage…or it could be partially responsible for starter solenoid “flutter”…but thats about it. It cannot make it grind.

Are you sure you are not confusing solenoid flutter with grinding? The two sounds are very distinct if you know and hear them often enough.

If your starter is in fact actually grinding…it may be due to the shaft that the gear of the starter slides upon… sometimes they get rusty or sticky and will make the starter grind. Sometimes the starter itself just needs to be moved a slight bit with the bolts loosened…or you can try a shim between starter and bell housing.

I would start with looking at the starter gear and the shaft the gear slides upon…it needs to be free and lubed. You also need a good solid battery as well because of the way the starter clutch functions…I wont go into all that at this time.

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The one way clutch in the starter drive is failing, replace the starter.

I would replace the negative terminal that you say has a stripped or failed nut and bolt. If you can just replace the bolt and nut, that is OK. But take the moment to remove the terminal from the battery and clean the surfaces with sandpaper or a wire brush. A poor ground connection can do lots of strange things.

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Thanks for the replies. I will change the bolts and clean the cable connections. The reason I was sure it was the relay is that back in 2015- after this exact same problem and exact same horrible loud noise (that was the first and only other time this happened) - I took the car to a repair shop and over the course of a month, they put in 3 new starters and it did not fix the problem. I went to the GM dealer and they put in this ignition / starting / battery harness with and added relay in there that was not part of the original setup. It was part of a recall for this car. 30 minutes after I left the dealer, the starter caught on fire. I towed it back to the repair shop. They kept it for 3 days and after all that, they said the original noise/starting problem was due to the recall work not having been done. But the fire was caused by a faulty relay that the dealer had put in. They put in a new relay and a new (4th) starter and it has been fine for the last 5 years. So after testing that relay that had been in there for 5 years about 5 times - having it fail and make the horrible sound 5 times - and then swapping the cooling fan relay and having it start perfectly with no noise for 7 or 8 times, you can see why this morning was so upsetting.

I fail to see how an electrical issue causes a grinding terrible sound. As advised above, replace the dang starter and make sure the teeth are properly aligned. Or next question might be “do I really need to remove the transmission to replace the flywheel”.

I’ll go against the grain and say that maybe something is damaging the relay. At this point, I would buy a replacement relay and see if it once again returns to starting as it should. Then look at what could be damaging the relay- drawing too much power or if the socket it’s plugged into has oxidized pins or something that is making bad connections…The relay is cheap, and easy to do. A lot cheaper and easier than a starter motor that may not fix the problem…


That’s exactly what the repair shop said before they replaced the first, second and third starters.

What about oil on the starter wire connections down at the starter? The whole starter and everything around it is covered with oil.

I tightened all the connections down there, and put yet another new bolt on the battery cable, cleaned the prongs on the temporary relay, looked for frayed wires - the only thing that appeared a little sketchy was the heavy, multiple-strands type ground where it connects to the metal battery tray coming out of the negative battery cable about 6" from the bolt. A little rusted but not falling apart. It is the only section of that cable that isn’t encased in the black plastic cover or the wire protector tubing.

Not all relays are created equal. Likely that the relay for the fan may be rated at say 10-15 amps, while the original starter relay -that apparently died- might be rated much higher amperage.
If that’s the case, the points / connections inside that fan relay may be toast.
Replace the starter relay with its equivalent, then see what happens.

Thanks for the reply. After putting another bolt on the negative battery cable, and tightening all those connections down on the starter, I had 16 consecutive good no-problem normal starts - and again thought the problem was fixed. Wrong. Last night - with nothing changed - again the same failure. I have spent hours searching on every automotive, and relay-related site I could think of - to try and find out if the relay that fits onto the end of the wiring harness (for the starter) is identical in every way to the other numerous relays - including the cooling fan which is what has been in the starter harness for those 16 good starts. From what everyone has told me - the only difference is the appearance (the relay on the starter harness has that big plastic hood that covers the seal and keeps water out, whereas the normal relays that go in the fuse box are just the plain cube types. None of the many online sellers that I have found lists the amps - and of course they are all 12v. And the 4 or 5 pin (87A) prong also doesn’t seem to make any difference as there are only the same 4 sockets for all the relays in the car. If I can’t find anything this morning online, I will drive up the road to the dreaded Chevy dealer (the one that - according to AAA put a faulty relay in that harness which caused the fire) and ask them about the relays. But the uses for each are all listed as the same (everything…horn, fan, etc…)

That won’t prevent the starter from grinding.Disconnect the wire that goes from the starter solonoid to the ignition switch.Clean the terminals(solonoid side) with sandpaper and make sure the connection is tight.See how it goes.

I assume this means you jumped those terminals in the relay socket (bypassing the relay) and the starting problem wasn’t fixed. If that’s the case, wouldn’t that imply that the relays aren’t the problem?

The original starter/crank relay, back in 2001, was different than the fan relay (at least they had different part numbers). The part numbers have since changed and they are both (for fan and starter) listed as multiuse relay, p/n 13503102. Also may be used for A/C clutch and DRL, et. al. Also shows up as a Delphi 15328864, which has a 35A capacity. ACDelco lists the starter relay as p/n D1741C.

Here is the problem. The relay is part of a non-original, added harness that was not on the car until recall work was done. The details of that are here:

There are two relays that I have - the one that the dealer put in as part of the recall work - and that the AAA repair shop said was faulty and caused the starter to catch on fire. This relay is an OMRON 12177235. The AAA shop put in a relay with 5 pins instead of 4 (the 87A pin is not used so apparently this does not matter) and this relay - that was in the car for the last 5 years and worked fine - has no manufacturer name on it - just two numbers - 412393 and 3210. I am familiar with the D1741C from all my Google searches. This appears to be identical to the cube type relays from the fuse box - including the cooling fan relay which I now have in the starter harness. These cube type relays are NOT the type in the harness for the starter.

Last night, I went to Advance Auto parts and had the guy pull up several of these relays in the hope that somewhere would be listed the amperage rating for each one so that I could know if that was part of the issue. I have not been able to find this information anywhere on the entire internet - and the Advance guy couldn’t find it either. It is like a national security secret.

I continue to get conflicting information and advice. Half the people say the relay has nothing to do with it - and that the relays for the cooling fan (the one I have in the starter harness now) are completely fine and interchangeable with the relay that was in there. The other half - including the Advance parts guy last night - made it sound like this problem was a no-brainer and that the whole problem was that I was using a relay with an amp rating not even close to what it should be and that is why it is not working 100% of the time right now.

All I know is that the percentage of good starts shot way up from 1/10 with the “bad”/original relay and now is about 75% with the temporary swapped-out cooling fan relay.

Post pictures of the relay(s) in question where we can see all of the numbers and trademarks on them. You may have to remove the special cover…

If you do a Google image search for “Omron 12177235” you can see what it looks like. It fits in here:


By the way, I’ve been trying to figure out how - if it is possible to separate the cube from inside this housing, but it appears to be all 1 piece and not possible.