function12

Any news? Did you get your car back?

TxBob74

I spoke with the service advisor late morning. He said parts had been ordered and had just arrived. Could not identify the part(s), though. Said he would talk to the Tech who had just left for lunch and call me this afternoon. No call, of course, so I will call him in the morning.

I emailed the SA and explained over the phone the theory offered earlier by Stronbl about voltage regulator malfunction at temperature. So hopefully they give the the charging system a thorough test.

TxBob74

The SA left me a voicemail message late yesterday after I had left the office and I spoke with him this morning. He said that they found a loose fuse box connection to the relay that would cause DME power loss when the car is jarred by road irregularities. He said they replaced the relay. They will test drive this morning up to full temperature and advise. So, with any luck, I should get the car back later today.

I will get more details when I pick up the car and post again this evening.

McCulla

Fingers crossed, this is a nightmare!

TxBob74

It appears that the nightmare is over. And without replacing a single part.

Yes, the dealer ordered the DME relay, but then opened the fuse box to find that the relay was loose in its socket. Apparently, one of the receiver clips (probably the wrong term; hopefully you know what I mean) had inadequate clamping force and the DME power circuit would open with just the right amount and speed of movement from vertical vehicle motion. So the tech adjusted the clip so that the relay is secured properly. They road tested the car without any faults and I drove 50+ trouble-free miles home.

I looked inside the fuse box and there is only one relay, located in the upper right. The fuse guide does not explain the relay. The tech's words written on the invoice: "Repaired loose terminal #85 in R11 DME Relay Relay Carrier #1". Unfortunately, I did not get to speak with him for a full interpretation.

If this adjustment has cured the problem, then my original theory about temperature being the culprit was wrong. It was the speed and force of suspension action on the freeway that caused the open circuit problem. With enough faults, the DME went into limp mode, causing the stall problem three weeks ago.

So it's time to get back to the fun stuff! This sounds like a very unusual occurrence. Hopefully everyone makes a few mental notes.

Alan C.

Great to hear that you are back on the road. Although I would like to think this was a one of a kind occurrence it's certainly worth noting for the future.

fskof

I'm glad it worked out for you! Now get out there and have some fun with the car!

gota911

Awesome! I am glad they got it sorted out for you.

subparrnd

Whew! Glad that it was a minor thing. Now go out and drive that thing before the rain hits us in a few days!!

BTW, I would let Momentum know that you won't be going back to them even though they are closer to you.....

Marshal_Mercer

Glad that you are back on the road.
If this is a standard relay's terminal 85, then it takes low amperage toward terminal 86 in order to open a closed, higher amperage switch, or close an open one (terminals 87 and/or 87a). It does not take much to throw this off but I have not seen vibration do the deed. I'd look instead at a faulty relay. This should be cheap to replace, if only for piece of mind.

TxBob74

Talking to Momentum is in my plans, but I am going to give it a couple of weeks, both to cool off a bit and have more confidence that North Houston has fixed the problem. Momentum isn't that much closer, but is an easier drive (much less I-45).

TxBob74

I wish that they had replaced the relay as well as correct the clamping force on the connector. But the dealer probably has to justify parts replacement and did not have evidence that it was defective. By the SA's description, the relay was really loose and something they had never seen. Will have to trust the Master Tech (Mike Molina) on this decision.

Skibum

The only thing that could be loose is the socket, as the relay only has blades.
Odd for a socket that has not been apart or otherwise abused to have a loose socket.

stronbl

Glad to hear the prognosis is on a more positive note. Even better if you are driving with a smile now. Thanks for keeping us in the loop. Mental note made!

Marshal_Mercer

Oddly enough, I've seen a fair number of internally rusted relays. Hella lighting was/is notorious for that. Not sure about Bosch, et al. This is another good reason to go with a solid-state unit in replacement of an electro-mechanical one.