Can a bad Ign relay cause car to die?
06-05-2017, 08:36 PM
#1
Can a bad Ign relay cause car to die? Last week, my car wouldnt start out of the blue. I had gotten home from work and everything was ok. A few hours later I was going to go out and the car wouldnt start. It would turn over and but just wouldnt start. Took the battery to get checked and it was ok, I then removed the ignition relay and put the #1 fan relay in its place. Boom, it started perfectly. So I go to autozone and buy a generic duralast relay part # 19307. I plug it in, and it starts ok. I let it warm up a bit and then the car sits over the weekend.
Come today (Monday), I drive the car to work (15 miles). I hear the exhaust kinda backfires a little more than usual like if its not running properly, but I keep going till I get to work. Then after work, I hop on and within a few minutes, waiting for the light, it starts to sputter/misfire and it shuts off on me. I turn the key and same issue, it turns over constantly, but wouldnt start. So i push it to the side (luckily I was next to a gas station).
So this time I switch the new ignition relay with the #1 fan relay, and still no start. I completely remove new generic relay (now on #1 fan spot), and it starts. Im able to drive back home but the car feels a little sluggish. Kinda like a slipping clutch. But nonetheless it makes it home.
So now I go back to try and recreate the issue, and the car starts with the generic ignition relay, however it does sound like its misfiring. I always have check engine light on due to the air and egr delete, so I plug it in and the only relatable codes are P0300 (misifire) and P0480 (cooling fan 1 malfunction). I guess the fan one is because I removed the fan relay temporarily to drive home.
So my question, will a bad ignition relay affect a car that is already turned on? I always thought it would make the car not start, but didnt think it would also stall once on.
Second question, will the bad ignition relay affect the cars performance?? I swear it felt sluggish with the new relay in place, but IDK if it was something else causing that.
And finally, will a ignition relay get weak before it dies, kinda like a fuel pump that starts showing signs? or is it like a light bulb, where it just completely dies and theres no turning it on at all. Im asking this because once I got home, the car started with the "faulty" relay.
Any info helps, Thanks
Come today (Monday), I drive the car to work (15 miles). I hear the exhaust kinda backfires a little more than usual like if its not running properly, but I keep going till I get to work. Then after work, I hop on and within a few minutes, waiting for the light, it starts to sputter/misfire and it shuts off on me. I turn the key and same issue, it turns over constantly, but wouldnt start. So i push it to the side (luckily I was next to a gas station).
So this time I switch the new ignition relay with the #1 fan relay, and still no start. I completely remove new generic relay (now on #1 fan spot), and it starts. Im able to drive back home but the car feels a little sluggish. Kinda like a slipping clutch. But nonetheless it makes it home.
So now I go back to try and recreate the issue, and the car starts with the generic ignition relay, however it does sound like its misfiring. I always have check engine light on due to the air and egr delete, so I plug it in and the only relatable codes are P0300 (misifire) and P0480 (cooling fan 1 malfunction). I guess the fan one is because I removed the fan relay temporarily to drive home.
So my question, will a bad ignition relay affect a car that is already turned on? I always thought it would make the car not start, but didnt think it would also stall once on.
Second question, will the bad ignition relay affect the cars performance?? I swear it felt sluggish with the new relay in place, but IDK if it was something else causing that.
And finally, will a ignition relay get weak before it dies, kinda like a fuel pump that starts showing signs? or is it like a light bulb, where it just completely dies and theres no turning it on at all. Im asking this because once I got home, the car started with the "faulty" relay.
Any info helps, Thanks
06-05-2017, 09:52 PM
#4
My car had several bad relays, cooling fan #3 was shot and would short my car out and die when the car went to high output both fans.
Ignition relay wouldn't cause the car to run rough, it sounds like it could be another problem causing a misfire. I would get a p0300 code after a random shutoff but never an actual misfire
My fuse box pins on the relay were even corroded
Ignition relay wouldn't cause the car to run rough, it sounds like it could be another problem causing a misfire. I would get a p0300 code after a random shutoff but never an actual misfire
My fuse box pins on the relay were even corroded
06-05-2017, 10:40 PM
#5
My car had several bad relays, cooling fan #3 was shot and would short my car out and die when the car went to high output both fans.
Ignition relay wouldn't cause the car to run rough, it sounds like it could be another problem causing a misfire. I would get a p0300 code after a random shutoff but never an actual misfire
My fuse box pins on the relay were even corroded
Ignition relay wouldn't cause the car to run rough, it sounds like it could be another problem causing a misfire. I would get a p0300 code after a random shutoff but never an actual misfire
My fuse box pins on the relay were even corroded
I didnt know the fan relays could cause starting issues. Ill check the remaining 2 fan relays and the fuse box pins tomorrow.
As for the AC, when i replaced the relay with the fan one, I drove it back home with the AC on setting 2. Would it make a difference if it was speed setting 2 vs 4 (max)??
I found a fan relay diagram here https://ls1tech.com/forums/conversio...-question.html but cant tell for sure.
06-05-2017, 11:43 PM
#6
Well I did have my ac at full blast when it died. I just went outside and did a little testing. All the fuses were good. I tested the new ignition relay I bought, and the starter relay, along with the fan #1 relay (which is now in the ignition relays spot), and they all tested fine. They clicked when they were connected to a power source and didnt show resistance when set to 20K ohms, with the power supply. Now I wish I hadnt thrown out the old relay. It probably wasnt the problem.
I didnt know the fan relays could cause starting issues. Ill check the remaining 2 fan relays and the fuse box pins tomorrow.
As for the AC, when i replaced the relay with the fan one, I drove it back home with the AC on setting 2. Would it make a difference if it was speed setting 2 vs 4 (max)??
I found a fan relay diagram here https://ls1tech.com/forums/conversio...-question.html but cant tell for sure.
I didnt know the fan relays could cause starting issues. Ill check the remaining 2 fan relays and the fuse box pins tomorrow.
As for the AC, when i replaced the relay with the fan one, I drove it back home with the AC on setting 2. Would it make a difference if it was speed setting 2 vs 4 (max)??
I found a fan relay diagram here https://ls1tech.com/forums/conversio...-question.html but cant tell for sure.
It is only used after the car reaches peak temperature and it kicks both fans into high output.
Like I said examine the pins inside the fuse box that the relays sit in for any damage.
The next thing to chase after the relays is to check your grand cables to the chassis. From the drivers side cylinder head, the ground strap behind the alternator, the ground on the radiator support behind the drivers headlight, the ground on the rad support by the rad cap, and the ground from the batter to the chassis by the shock tower. Inspect for rust and corrosion
06-06-2017, 12:22 AM
#7
The 5 pin relay on the right is cooling fan relay #3. It is the only unique relay, the only one with 5 pins.
It is only used after the car reaches peak temperature and it kicks both fans into high output.
Like I said examine the pins inside the fuse box that the relays sit in for any damage.
The next thing to chase after the relays is to check your grand cables to the chassis. From the drivers side cylinder head, the ground strap behind the alternator, the ground on the radiator support behind the drivers headlight, the ground on the rad support by the rad cap, and the ground from the batter to the chassis by the shock tower. Inspect for rust and corrosion
It is only used after the car reaches peak temperature and it kicks both fans into high output.
Like I said examine the pins inside the fuse box that the relays sit in for any damage.
The next thing to chase after the relays is to check your grand cables to the chassis. From the drivers side cylinder head, the ground strap behind the alternator, the ground on the radiator support behind the drivers headlight, the ground on the rad support by the rad cap, and the ground from the batter to the chassis by the shock tower. Inspect for rust and corrosion
I had checked the ground cables not too long ago, but ill also recheck them if the relays dont solve anything.
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06-06-2017, 04:12 AM
#9
Could a bad ign relay cause a car to die? I'm not 100% familiar with the ign circuits in the car, but I would say yes.
A relay is nothing more than an electronically controlled switch. If you turn off a relay it is the same as turning the key off in the cylinder.
However, most relays don't show intermittent issues. Some will stick, some will fail outright due to poor contact. My guess if you're having an intermittent issues is corrosion on the pins, the internal contacts of the relay itself, and possible poor grounds.
A relay is nothing more than an electronically controlled switch. If you turn off a relay it is the same as turning the key off in the cylinder.
However, most relays don't show intermittent issues. Some will stick, some will fail outright due to poor contact. My guess if you're having an intermittent issues is corrosion on the pins, the internal contacts of the relay itself, and possible poor grounds.
06-06-2017, 01:02 PM
#10
Is there anything I can use to clean up the fuse box sockets? I heard spraying wd40 helps prevent corrosion on battery terminals, but i dont just want to spray stuff into the fuse box.
As for the misfire im going to buy a scanner that tells me which cylinder is misfiring. My current OBD2 scanner wont tell me that info. I guess ill be doing my plugs and wires sooner than I planned.
As for the misfire im going to buy a scanner that tells me which cylinder is misfiring. My current OBD2 scanner wont tell me that info. I guess ill be doing my plugs and wires sooner than I planned.
06-06-2017, 02:59 PM
#11
I typically recommend a wire brush or sandpaper (320 grit works well). WD40 will help as a corrosion inhibitor, but it won't get rid of the corrosion that's already there.
Spraying water or wd40 into the fusebox generally won't hurt anything. Both are actually poor conductors of electricity, so over the large distances between pins it won't really short circuit. That being said, I wouldn't think it's worth it. We're talking about corrosion that's built up for the past 15+ years. Unlikely to happen again in the car's life lol.
Spraying water or wd40 into the fusebox generally won't hurt anything. Both are actually poor conductors of electricity, so over the large distances between pins it won't really short circuit. That being said, I wouldn't think it's worth it. We're talking about corrosion that's built up for the past 15+ years. Unlikely to happen again in the car's life lol.
06-06-2017, 10:28 PM
#15
To test that 5 pin relay, with the relay not energized, you should have continuity between pins 30 and 87a (normally closed) and no continuity between 30 and 87 (normally open).
When pins 85 and 86 have power and ground (relay energized), you should have continuity between pins 30 and 87, and pins 30 and 87a should now be open.
When pins 85 and 86 have power and ground (relay energized), you should have continuity between pins 30 and 87, and pins 30 and 87a should now be open.
06-07-2017, 12:07 AM
#17
Ill look into the crank and cam sensor. Is there anyway to test them to narrow the issue down? and are they difficult to replace?
06-07-2017, 08:09 PM
#18
The cam sensor is behind the intake manifold, the crank sensor is behind the starter on the passenger side of the block. Crank sensor would be pretty easy (just drop started, unbolt crank sensor and replace) but cam sensor would require removal of the intake manifold (unless you're really good with a mirror)
06-07-2017, 09:50 PM
#19
Is there anyway to narrow it down to the crank or cam sensor being the issue? I want to avoid spending 40+ bucks on a sensor only for it not to work. Ive only seen someone test it with a crank reluctor wheel, but I dont have that available.
