Riggs

I am planning on ripping out my dash soon to investigate what I believe to be some electrical issues. Both the battery and alternator are brand new, only a few days of use.

1. My volt meter, as of today reads NOTHING. However, my car does run. It does not start. In other words it can be push started but it cannot start with its own battery. In other words the alternator is working just fine insofar as providing power to the engine when it is running. I know this because I can disconnect the positive terminal on the battery and the car still runs. Also, this is a day to day issue it seems. I will also be checking for loose/dirty connections on the battery. Yesterday it read nothing but I was able to start the car normally and about half way through the commute to work, *ding* my volt meter popped up to nominal reading. It has been acting like that for a few days now, except today as it never came up from the 0 reading.

2. My temperature guage likes to creep alllllll the way up to the top of its range within about 10-15 seconds of starting the car. obviously its not heating up that high at all, and within a few minutes the guage comes back down to the middle and stays there.

3. This morning when I tried starting the car, I heard the fuel pump powering up nice and strong, but the starter didnt make a sound. Time for a new starter?

Any help or insight to these issues would be greatly appreciated.

Riggs

OK quick update.

I made sure to check the connections from the alternator I installed, and was surprised to see that the lock washer on the lead to the battery had NOT done its job. Nothing a little locktite and a good torqueing can't cure. Jumped the car, she started up just fine and ran like a champ. Volt guage immediately jumped up to about 13V, and the temp guage didnt automatically creep up to the top of it range like it usually does. It was fine for the rest of the day yesterday. Then this morning, the guages were back to their old thing. Car still starts as if it WANTS to run, but the volt and temp guages are both on my shitlist again. Volt guage reads nothing and the temp guage does its creep then eventually goes down to nominal, seemingly when/shortly after I turn on the heater... ?

Any ideas?

Zero10

Sounds like you need to check your grounds. There are a number of them scattered around the engine bay and they all need to be clean and tightly connected.

Riggs

This is what I was thinking, but a coworker told me it almost sounds like a bad ECU because there is more than one guage acting up. Hopefully the issue is solved beforeI have to go to those lengths, at that point I would just start saving for a standalone and start budgeting for a hot smog every two years. Damned CA smog *****.

I will have to get the car up on her side a bit and take a poke around her belly. take some electrical cleaner to the battery terms and random connects. EDIT: I'm an electrical noob (besides audio, I'm a live and studio engineer), but wouldnt it be cleaner and more effective to run the random grounds back to the negative term on the batt? readreadread. Gah I feel like I did when I first got my pignose. lol.


Also, my car came with an SAFC unit and an AFR guage in the A-pillar (guage wasn't hooked up at all). I'm thinking either the previous owner was paranoid/delusional or the car was turbocharged at some point. I'm told/have read that the stock S5 engine has too much compression for this and would detonate with relatively little boost. I'm going to start looking into reading the engine codes off of 13Bs and see what the hell is up with that. The thought that I could possibly be rocking an S4 engine in my S5 chassis is a bit of a double edged sword if my thoughts concerning the lower comp rate of the S4 engine are true. readreadread. and read more.

Thanks for the info Zero10, as well as anyone else who ends up throwing some input.

Zero10

How can it possibly be cleaner to run a bunch of extra ground wires back to the battery?

The factory grounds are in the right places and if in good shape do their job perfectly well for stock electrics. Some of them are a bit of a pain to get to but I'd focus on engine grounds, main battery ground, cluster ground and interior grounds near the CPU and ECU. Hopefully one of them will be the culprit.

Riggs

I was planning on keeping it all to a minimum by installing a grounding block or two with a single lead to the negative battery terminal. It's just an idea at this point, and would probably be a baby step towards gradually tucking everything in the bay. I would most likely Techflex everything and definitely route it all as inconspicuously as possible. Trust me the point of the idea is to make everything look simpler while making the current flow cleaner.

misterstyx69

iTrader: (142)

Did you put the Connector at the back of the alternator on? (L,and S.)
that connector allows the gauge to read 12 volts and also supplies voltage to the alternator so it can charge.

Riggs

You mean the plastic harness bit that plugs into the top of the alt? If so, yes. I am about to inspect it thoroughly to make sure the harness is good. The thought that it had something to do with the issues definitely has been on my mind.

I'm going to use a toner to send signal through those wires to the other end. I'm assuming at least one ends at the back of the cluster? so many connections to check!