What amperage is the charging system relay on a 2g?

[Cesar]

What amperage is the charging system relay on a 2g?

 

[luv2rallye]

I know of no relay in the charging system.

 

[Cesar]

The one for the charging system warning light next to the boost control solenoid.
Mine seems to be broken and I would like to replace it with an aftermarket one.

 

[95blackGsTurbo]

Why would you wanna replace it with an aftermarket one? So you can run more amperage and burn crap up before the light come's on? Go with the stock relay.

 

[luv2rallye]

Ah that one - called the generator relay in the Mitsu manual. From the Mitsu manual: "The generator relay functions as a backup for the flow of electricity to the rotor coil (field coil) if there is a disconnection or damaged wiring of the charging warning light." It actually is a resistor and diode in series but looks like and is referred to as a relay. (FYI: It is connected in parallel to the charging warning light, it's diode and the 10A fuse.) Something must be banging into it as I hear quite a few complaints of it being distroyed (and mine is missing for some reason). Don't know the amperage rating. You may have a problem getting an aftermarket one as every time I've asked they say they never heard of it. Should you find an aftermarket let us know where you got it and the price.

 

[Cesar]

Why would you wanna replace it with an aftermarket one? So you can run more amperage and burn crap up before the light come's on? Go with the stock relay.

I don't want to increase the amperage, I would like to match it.

besides, the factory one is probably more expensive. I've seen relays going for 5 bucks with a new harness.

So it's not like a regular relay?

what's the Omron number on the front of it?

 

[perley03]

Part #MD128752, should be able to order from your dealer.

 

[luv2rallye]

So it's not like a regular relay?

That is correct. It's a special kind of device they chose to call a relay. I doubt you'll find it anywhere but the dealer.

10/20/2011: NAPA apparantly has it: http://www.dsmtuners.com/threads/help-figuring-out-what-relay-this-is.417383/#post-152762759

 

[Defiant]

It's one of the common "what is this?" post sources. Usually, with the guts ripped free from the metal case. Other than the bafflement, I don't know of it being a source of trouble.

 

[luv2rallye]

I asked a mechanic at Mitsubishi and he said it's not necessary to have. In fact they did away with it on 2000 and later models. And when he looked up my VIN on my 99 GST, it said it didn't have one (which it doesn't) even though their own 99 Eclipse manual shows it. He said it was probably a cost savings thing that got done at the factory or post engineering which often doesn't show up in the manual. He couldn't even find a tech bulletin about it but he said that's not uncommon for a cost saving change like this.

 

[DSM_PWR]

Sorry to bring back the dead, but i just got done with re-wiring my fusebox wiring harness and I heard that this relay wasnt necessary to have, but does anyone have proof? I cant help but think that i did a mistake by removing it from the harness and just wanna be absolutely sure!

 

[Defiant]

Like you were just told, it isn't a relay, despite what Mits calls it. Post #5.

 

[forcefed86]

I know this is an old post but I’m having problems with the Alternator “relay” on my 1g. I pulled the cover to look at it and it’s sure not relay! If this is not needed what is the solution to removing it? Looks like 4 terminals. I’d assume I could just jump 2 of them? If this is the case what will happen to the dash battery light?

 

[luv2rallye]

Don't jumper them or you risk a back feed on the ignition switch. Either leave it off (and make sure your dash charge light always works) or put in a diode in series with a resistor (like the relay was). Any diode rated at 100v (piv) but I can't tell you the resistor value as mine doesn't have one (I'd guess probably around 100 ohms - value not critical).

 

[forcefed86]

Don't jumper them or you risk a back feed on the ignition switch. Either leave it off (and make sure your dash charge light always works) or put in a diode in series with a resistor (like the relay was). Any diode rated at 100v (piv) but I can't tell you the resistor value as mine doesn't have one (I'd guess probably around 100 ohms - value not critical).

So after a weekend in FLA I'm back home now and got a chance to work on this some more. Bought a simple diode at radio shack. And it fixed my run-on issues. Key shuts off the car as it should now. But I have another issue. Not sure if the alternator relay resistor is to blame here or not. I'm guessing it is. With the car shut off I can hear the ISC motor clicking away. If I pop out the alt relay it's dead quiet. Reinstall it and it starts clicking again. Also the resistor on the alt. relay is quite warm.

I'm guessing I fried the resistor when I fried the diode? I'm not really sure of the purpose of the resistor? Does anyone know.

Here are a few pics. I didn't have a "solder sucker" so I used compressed air to blow out the old solder. It's a bit messy, but it worked.

Original pic of alt. relay

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replacement diode

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New diode installed

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Boost switch setup...

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Small vid of voltage boost...

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[luv2rallye]

DO NOT USE A ZENER DIODE!!! I guess I assumed you would use a power rectifier type of diode - I should have told you. [The zener is for tiny signal voltages only and has a special reverse voltage function that you cannot have here.] So it instantly blew and shorted itself which is your problem (and perhaps why you're getting the ISC clicking). You need to use a voltage rectifier power diode (looks like the one in your original relay pic) that can handle 2-5 amps minimum (these typically are used in AC to DC power supplys). It's cathode (end with black ring/mark on it) must be connected to the alt relay connector pin 2 white wire (which is the wire that goes to the alt "L" terminal). The other diode end should connect to the resistor and from it to the alt relay connector pin 4 black-white (which goes to ignition switch).

The resistor should be around 100 ohms but needs to be 2.5 watts minimum to handle any heat generated (it looks like the one in your original relay pic). It's purpose is to limit the current flowing through the diode.

This voltage booster you're adding. Are you trying to fake the alt out into thinking the battery voltage is lower than it actually is so it needs to put out higher voltage? These alts have an internal voltage regulator. Does the alt on your other car using a CS series GM alternator have an internal regulator? I need to see a schematic drawing of it to see if it will cause any problems. Send it to [email protected] or post it here.

 

[LunarEclips]

This is interesting to see his car run at 15+ volts. I know most electrical components take at the most 16volts input. (for example car audio radios, HID and xenon bulbs). How is this beneficial?

 

[steve]

DO NOT USE A ZENER DIODE!!! I guess I assumed you would use a power rectifier type of diode - I should have told you.

I did. http://www.dsmtuners.com/forums/152299049-post11.html

 

[forcefed86]

Thanks for the suggestions...

I actually noticed that last night and installed this diode in its place. It may have blown due to the low amperage. Although it is not back feeding as the car shuts off.

I drove it for around 30mins last night. Is the resistors function also to stop excessive voltage/wattage from shorting the diode? I did look for the diode steve described, my local radio shack did not have anything similar.

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It does the same thing. ISC motor clicks away with the IGN off...

FYI the diode never blew (that I could tell) The car still shut off. Although I only ran it at idle and during that short video clip before changing it.

You want the schematic drawing of the wiring? Or my alternator? The CS series alternator has an internal regulator as well.

I just ran a SPDT switch inline with the voltage Sense wire. NC is see's oem wiring. when the switch opens it sees what ever voltage I input.

 

[steve]

That is a 400X diode, a 1N4003 200V PIV 1A version.

 

[forcefed86]

That is a 400X diode, a 1N4003 200V PIV 1A version.

And I have the black band on the diode facing up. Same as the first photo of the OEM diode. This is correct?

If it were back feeding wouldn't the car continue to run as it did when I jumped the diode terms? Not sure where the ISC is drawing power from. The source wire should read bat voltage with the IGN off. According to the manual.

 

[steve]

And I have the black band on the diode facing up. Same as the first photo of the OEM diode. This is correct?

No, a printed band marks the cathode, it doesn't have to be black. In this case it's silver. Just like the on 4003 diode you bought from Radio Shack.

See the other thread for details.

 

[luv2rallye]

Is the resistors function also to stop excessive voltage/wattage from shorting the diode?

FYI the diode never blew (that I could tell).

You want the schematic drawing of the wiring?

The resistors function is to limit the current flow through the diode. What value resistance and power wattage is the resistor you are using?

The minimum current rating of the diode you should use depends on the resistor value. But using a larger current rating of diode doesn't hurt anything and is better. Test to see if your diode is shorted. Unplug your new alt relay and measure the resistance across the diode first one way and then the other way (reversed). It should read different values but not zero. If it's shorted, that is your power source for the ISC.

The schematic drawing I want to see is your voltage booster.

LunerEclips has a good point. Having too high a voltage can damage components. Most things can handle 16v and some even 20-25 (Steve step in here with your knowledge) but why risk it? ECU and radios cost hundreds to replace. Lights however are another story - anything over around 15.5 is going to seriously reduce lifetime and will burn them out prematurely. Why do you want to do this again? Most things are designed for a certain voltage (including FP) which is what they operate best at. Higher than it reduces efficiency, reduces lifetime, and may even cause damage. If your reason is to provide higher voltage to the FP, you'd be better off doing the FP rewire mod. If you're not getting at least 12v on it while running, then you have some other problem.

 

[forcefed86]

I'm running a denso TT supra pump and E85. These pumps (and walbro's) are more than capable of 16v+ and run very well in these ranges. I have already done the FP re-wire.

But this pumps performance jumps up roughly 50lph at 15.5v. Since I plan to run 30psi plus on my 16g, my fuel pressure’s will be high and fuel flow will be down. . I see it as cheap insurance. Also it may help ignition etc at boost.

I will have my switch set at 25psi so the time spent in voltage "boost" is very short. I know many that run the caspers voltage booster. This jumps voltage to the 16v range and I’ve never heard of anyone having an issue. I also run this on my buick without issues.

This is uncharted territory as far as I know with a DSM alternator. So I’m not suggesting anyone try it. I don’t believe it will hurt anything, time will tell.

 

[luv2rallye]

ok well good luck. I'd still like to see a schematic of the voltage boost circuitry though. Send it to my email as an attachment.