# Anatomy of the Cruze Ignition Relay



## NickD (Dec 10, 2011)

Contacts are of a silver alloy, coil resistance is 80 ohms paralleled by a 680 ohm 1/4 resistor for some weak form of inductive flyback protection.

Contact resistance was high, can't view this in the photo, but the contacts for both the armature and the fixed contact had a ring of carbon around it, Was very easy to burnish this carbon of. And now the contacts are making excellent contact.

With that carbon in the way, still was making a stuttering type of contact that could very easily fool the power on reset for the microcontrollers. The cover was very well glued on, so rather than breaking it, cut it. Its glued back on solid again, and perhaps good for another 40K miles.

Panasonic makes an exact equivalent, their model number CB1AH-12V with a contact rating of 70 amperes, but holding off until I have a couple more items to order.

View attachment 165330


Never was much a fan of point contact relays because of this carbon arcing, a real ignition switch has sliding self cleaning contacts. The relay has just four standard 1/4" spade lugs, the two opposing contacts that are at right angle to each other are the two contacts. Going to make a short jumper with two mail spades on it and toss it in the glove compartment, just in case. Hate to be stranded just because of a tad of carbon.

Seems to have been the cause of my radio flashing on and off as the first indication.


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## ChevyGuy (Dec 13, 2014)

NickD said:


> Panasonic makes an exact equivalent, their model number CB1AH-12V with a contact rating of 70 amperes, but holding off until I have a couple more items to order.


Where are you ordering from, Mouser? Digi-Key? I may want to get one as well. Nice job.

Just checked, Amazon is pricey, but with Prime only $67 for today....


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## Tomko (Jun 1, 2013)

Nick - what did you use to cut it open?


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## NickD (Dec 10, 2011)

My square and a sharp utility knife and a steady hand, cuts like butter. Both Digi-Key and Mouser are out of stock, runs around 6 bucks, but shipping runs more than this.

Other places I checked have a 50 buck minimum. Least I know I have clean contacts now.


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## ChevyGuy (Dec 13, 2014)

NickD said:


> Both Digi-Key and Mouser are out of stock, runs around 6 bucks, but shipping runs more than this.
> 
> Other places I checked have a 50 buck minimum.


Amazon

Yeah, expensive, but so are those other places if you're not ordering much.


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## brian v (Dec 25, 2011)

Shoot you can find them at a wreckers cheap and since your refreshing em .. we'll go in buisness since there is over 6 million cruzens sold todate !


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## NickD (Dec 10, 2011)

Not around here, only way they would know how to unplug that relay is with an acetylene torch and would insist on I would half the front of the vehicle to get it. 

A relay is essentially a current amplifier, 150 ma in, up to 45 amperes out, switched on by the key logic with 12V, low side of the solenoid is ground. One contact connected to 12V open contact to the ECU load. Thinking more in terms of inputting that 12V to the base of an NPN transistor to switch on a P-channel power MOSFET transistor, these also have practically infinite gain. 

Would take some testing as that rise time is critical, in a microcontroller, the POR pin has to be held low with 5 volts applied for the power, this is done with a grounded capacitor tied to the POR pin with a resistor going up to 5 volts. Had some problems where the idiot designer used a capacitor to small where its charge voltage would follow that applied 5 volts. Installing a much larger capacitor cured that. Easy to spot with a dual trace scope. 

One thing about automotive, is 12 volts and does not have to follow NEC rules, have a 50 ampere contactor that I practically need a wheel barrow to carry. This tiny toy is nothing short of a very bad joke. 

Also looking at the other relays, a whole bunch of them with potential problems, primarily concerned with the ones that would leave me stranded. Also the power windows, not good when you can bring them down, but not good if they won't go back up. Especially in a thunderstorm.

Had this experience in a Lincoln at the Illinois toll booth with a long drive home and got soaking wet. Repairing the window was easy, but not easy to pull the entire interior to dry it out. One reason why I wish my Cruze had manual windows, they always work. 

Another so-called convenience item that can be a super great inconvenience.


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## ChevyGuy (Dec 13, 2014)

Any particular reason for choosing Panasonic? I've used their caps in the past and like them, but I've never used their relays. A two-way radio installer I know says Bosch is good for automotive relays.


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## NickD (Dec 10, 2011)

Just the first one I found, should be others. Ha, you mentions Bosch that my Volvo I/O used in my boat for of all things, a starter relay. Another bad joke and problems.

View attachment 165386


That little toy on the right is what they were using, looks very similar to the relay used in the Cruze ignition. Replaced that piece of crap with an aircraft quality starter relay on the left. Not fun being stranded in the middle of lake and the engine won't start, but at least I had a jumper wire to get it going. They don't put a pull starter on a Chevy 5.0 L engine.

This reminds me, that 02 starter relay in the Cruze is also a toy in the underhood fuse/relay box. But do have a manual transmission and already learned I can push start it. 

Here is a photo of the Cruze starter relay, does have a pop off cover.

View attachment 165394


Fortunately the contacts are in real good shape with 40K miles on the car, so may not be a problem.


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## jmaotto (Jul 29, 2012)

Where is that ignition relay located?


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## NickD (Dec 10, 2011)

Three tabs on your under hood fuse/relay box, have to squeeze those to release the cover. Under the cover shows all the fuses and relays and relative locations.


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## ChevyGuy (Dec 13, 2014)

NickD said:


> Seems to have been the cause of my radio flashing on and off as the first indication.


Which relay is this? According to my '13 manuals, the radio is powered off the battery saver relay, not the ignition. Otherwise it would shut off the moment you killed the ignition.


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## jblackburn (Apr 14, 2012)

Aren't radios turning off and on one of the first signs of the infamous battery cable going bad?


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## NickD (Dec 10, 2011)

Learned all about corroded battery terminals on my 1930 Olds I purchased for ten buck when I was 13 years old. Been keeping these clean and tight ever since. Was 16 years old when I purchased a 1937 Olds, first car with a radio that didn't work. So learned about dirty contacts in a Mallory Vibrator that was used a chopper to convert DC into high voltage AC with a transformer. Cleaned those contacts so I could listen to WLS out of Chicago. 

Cruse has a basket full of relays that can have dirty contacts, so not just one problem can be another one as well. 
 
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