1997 Q45T alternator issue?

[chrisbr66]

Looking for some assistance with an issue with my 1997 q45T The car will start and idle for approximately 10 to 15 minutes and then will just stop like the battery died. I first tried a new battery since the existing was pretty old, but the issue persisted. I used a multimeter and had a reading of 12.6V with the engine off. With the engine running had a pretty consistent reading of between 13.2 to 13.7 I do not hear any unusual noises coming from the alternator and the belt feels good. Any ideas what I should check or should I replace the alternator? If it is an alternator how difficult is the install of a new one? Thanks in advance for any help.

[VStar650CL]

Running for 10~15 minutes is probably just long enough for it to reach temperature and go from open loop to closed loop. That implies a fuel problem, assuming the MIL isn't lit. If the MIL is lit, it could be lots of things and you really need to pull codes.

[VStar650CL]

PS - Those alternator and battery readings are pretty healthy. Unless maybe you have a bad connection somewhere, you're probably barking up the wrong tree with that.

[chrisbr66]

Thanks, used a reader and did not get any codes

[VStar650CL]

Then I'd say the next step is to check your fuel pressure and pressure regulator.

[chrisbr66]

So I decided to hook up the code reader last night to check for codes again, did not get any codes but the weird thing is the code reader would only connect with the engine running. If in ignition selection 1 or 2 it could not communicate. Makes me wonder if there is an underlying electrical issue I am missing

[VStar650CL]

That is weird. The ECM isn't awake in Acc but it should be alive with the key in Ign but not running. Maybe your ECCS relay is going south and needs the extra voltage from the alternator to make contact. I've seen that a couple times before, and I can't think of anything else which could cause that symptom.

[chrisbr66]

Is that relay located on the interior passenger side?

[VStar650CL]

I think so, yes. It's in that area on most of the old stuff.

[chrisbr66]

Finally got around to looking for the relay, I think I found it but it's listed as an EGI relay is that the same thing?

https://www.infinitipartsdeal.com/parts ... m=252_A002

[VStar650CL]

Yep. They call the engine control harness an "EGI Harness" too. Only the parts people know what that means, you won't find it called that in any FSM. Japlish strikes again.