periodical lack of voltage, not alternator

Good day!
First time it happened at the end of hot sunny day. I was in traffic with turned on AC and headlights. Suddenly I noticed tan high beamand right turn signs on dash. Then AC turned off, headlamps becomes dim, motor temperature began to raise because of lower than normal fans speed.

The symptom disappears afer several minutes of highway ride with turned off all electrical appliances and sometimes after irregularity of the road. Sometimes it repeats, sometimes it`s all right for hours.

I checked alternator voltage at the time of problem - it`s normal, about 14v. Reconnected the battery - it still happens.

What`s problem? What should I inspect next?

Just because the Alternator is putting out 14v doesn't mean it's putting out enough Amperage. Maybe one of the diode packs internal to it is going bad when it gets hot. Does the battery light come on on the left side of the dash?

If hitting bumps in the road make the problem come and go then I would suggest checking for loose connectors or damaged wires. Seeing as its affecting so many different things I would check the major areas first, ie near the battery, the fuses boxes, the computer, and the firewall pass-thru. Loose or shorted wires can cause all sorts of havoc. While you're checking keep an eye out for water, as it can cause all the same problems, but that's less likely cause once its wet a bump in the road won't make it go away.

The battery doesn`t light. I see high beamand right turn signs on dash even in "ignition" key position (motor cold).
Another detail: when I push horn button theese signs become brighter! My colleague says it`s related with "mass" wiring

If you plan to fix the car at all costs, it makes sense to replace the battery first if it's more than 5 years old. Might take alleviate some of the problems.

I replaced new Varta 100Ah battery one year ago

georgeman wrote:

The battery doesn`t light. I see high beamand right turn signs on dash even in "ignition" key position (motor cold).
Another detail: when I push horn button theese signs become brighter! My colleague says it`s related with "mass" wiring

Sounds like there is either a short or a "sneak circuit" somewhere. The first & cheapest thing to do is to check all the fuses in the dash, under the hood, and under the back seat - I believe there are 57 of them...

georgeman wrote:

The battery doesn`t light. I see high beamand right turn signs on dash even in "ignition" key position (motor cold).
Another detail: when I push horn button theese signs become brighter! My colleague says it`s related with "mass" wiring

Ignition Switch?! The almighty elusive electrical problem......???

georgeman wrote:

I replaced new Varta 100Ah battery one year ago

That does not sound like the right battery.

The Riv requires a Group 79 battery, with vent pipes attached, so the fumes from battery are vented through the floor of the car. You must do this or else over the course of a few months the acid fumes will rust and create holes in the floor of the car.

The battery also must be more than 800 CCAs. The Riviera uses a lot of electricity even when it is off. The radio, keyless remote receiver, anti-theft, and other systems are all 'on' all the time. you *cannot* skimp on the battery for long. The Varta 100Ah is only 800 CCAs, that is not enough. You need to get a bigger battery. Don't get me wrong, the Varta will work for a while. But as it ages teh power will drop off a lot because of the high drain when the car is off, and you will have these problems and more. An Exide Maxx 900 (a 50 Ah battey with 900 CCAs) is more like what's needed for the type of load the Riviera presents, but does not have proper venting capability. It is fewer amp-hours but more CCAs. What you probably want to do is ask a battery fitter to help you find a battery with proper venting capability and the power of the Exide Maxx 900 that will fit under the Riv's rear seat. My guess is the fitter will recommend an Optima, for which you'll need to fabricate a mount out of a plastic household cutting-board.

It is easy to imagine that in the space of a year the battery is run down too low. How to check - disconnect the battery and measure its voltage with voltmeter. If battery is putting out less than 12.4 volts, it is not charged enough. If it is putting out less than 11 volts, it has at least one dying or dead cell and most likely must be replaced.

As for the other problems, they will be hard to find if you have a battery problem becuase so many of the electronic systems depend on having the right voltage to work. However, you should look for physical problems -- I would say most likely place to start looking is the big wiring harness connection at the firewall (cowl) of the car. Look for deformed female terminals caused by other people who tested the wiring wrong in the past; look for internittent shorts in the harness especially at splice locations and near connectors (wiggle the wires); look for broken strands in the wire harness (in your case most likely steering column, at firewall, or under dash behind insturment cluster - anyplace where wires are flexing or where wires have been repaired).

Albertj

Albert do you think its possible, if he's using an un-vented battery as it seems he might be, that the fumes could be causing some of his problems? It would seem to me that if the fumes will eat away at the floorpan and the seat bottom then it will eat away at all the wiring as well. If I'm not mistaken the relay for the horn, if not the rest, are under the seat. Good luck Georgeman

A quick peak under the seat would tell the story, but I doubt that's it, unless he chose a low-end battery.

The VARTA Ultra series is sealed, spill and leak proof. If he chose this type, I think it's ok. If not, just inspect under the rear seat a couple times a year to monitor any corrosion problems.

800 CCA may not technically be "enough", but unless it's cold out and having starting toubles, I'd say it's a non-issue. The fact that the battery is only a year old means it's probably more than adequate compared to a "correct" battery that is old and tired. The idea that the car uses amps while it is off, and this can add up over a long period - I'm not sure I believe that. Every time the car is started, the battery gets a fresh charging to reset the voltage and amps. If the battery is keeping above 12 volts with car off, and it starts the car, it should be good.

All of his other tips are correct, but I disagree with Albert on the CCA... If the Varta is truly 800 Cold Cranking Amps, that is plenty of power. After all, the latest Delco replacement for our original battery is down to 840...

Also, if the Varta has 100 Amp-hours, that corresponds to 240 minutes of reserve capacity, compared with the Delco's 140.

Eldo wrote:

All of his other tips are correct, but I disagree with Albert on the CCA... If the Varta is truly 800 Cold Cranking Amps, that is plenty of power. After all, the latest Delco replacement for our original battery is down to 840...

Also, if the Varta has 100 Amp-hours, that corresponds to 240 minutes of reserve capacity, compared with the Delco's 140.

Good points but reserve capacity may not be the problem. A 100 Ah battery sounds like a boat battery - long sitting times, then long run times, infrequent starts. The frequent starting ahd short run times of most European drivers will kill off such a battery in an auto, in 8 mos to 1.5 years. Starting takes a lot of juice, and the run times are not adequate to recharge fully. A better idea would be a battery with more CCAs and less Ah capacity. It would produce a lot of current for starting and would not take as long to recharge.

First and foremost I think this gent George has a wiring problem to find. I bet there's splices in the steering column or under the dash, or in the engine compartment, that are causing problems. I wonder if this RIv was wrecked and rebuilt?

Albertj

albertj wrote:

First and foremost I think this gent George has a wiring problem to find. I bet there's splices in the steering column or under the dash, or in the engine compartment, that are causing problems. I wonder if this RIv was wrecked and rebuilt?

Albertj

I wonder this - have the lights been converted to european lighting? I know they require different lights, and any mistakes in the wiring involved could be causing the shorts he is describing.

Derek wrote:

Albert do you think its possible, if he's using an un-vented battery as it seems he might be, that the fumes could be causing some of his problems? It would seem to me that if the fumes will eat away at the floorpan and the seat bottom then it will eat away at all the wiring as well. If I'm not mistaken the relay for the horn, if not the rest, are under the seat. Good luck Georgeman

I don't know if corrosion from the fumes is a problem. Not saying it is or it is not, just saying without looking at the thing I can't tell and the relays are sealed such that they are a little tough to inspect. Corrosion on the wires or connectors is a strong hint that there's maybe a relay problem. A hint would be, what battery was in it before installing the Varta 100Ah?

That said, visual inspection of the wiring under the rear seat is a must. Maybe the car was flooded? I would pull off a door panel and look for mud in the bottom. I would take off the driver or passenger side kick plate and check for mud underneath. People flipping flooded cars often don't pull any panels to clean out the cavities. Anyway, once you figure out how high the water got, it's easier to figure out what's probably busted.

RIght now my best guess is the car was in an accident or had a fire and the repairs to the wiring were not so good. George says he has a problem but does not say if he has always had such problems since he owned the car or if they developed while he has had it. he does not say if he put on an aftermarket alarm. And so on.

A typical Riv fire would have been from a drippy rear valve cover problem or the nylon fuel line problem. Typically an accident would be an area of difficulty if in teh wreck the steering column was damaged and rapaired instead of replaced along with its wiring. I'd pull off the panel under the steering column and look for repaired areas in the wiring - as well as fixing the battery issues. I'd start from the firewall connector and work back into engine to check the engine side of the main wiring harness. And I'd get an FSM to get the wiring diagrams, 'cause a look at the diagrams couldn't hurt.

We will see what more George has to say.

Albertj

deekster_caddy wrote:

albertj wrote:

First and foremost I think this gent George has a wiring problem to find. I bet there's splices in the steering column or under the dash, or in the engine compartment, that are causing problems. I wonder if this RIv was wrecked and rebuilt?

Albertj

I wonder this - have the lights been converted to european lighting? I know they require different lights, and any mistakes in the wiring involved could be causing the shorts he is describing.

Yep, depends on who did the rewiring and if they accounted for the DRLs. If not they could have fried the lighting module.

Albertj

Thanks for lively discussion!
Checked around battery place today - looks good (by the way I used dying Bosch Silver 85Ah before and had no problems).
I ride Riviera during 3 years. That`s first serious electrical problem, faced me two weeks ago. Previous owner wrecked car a little in front, but it`s dry and clear under cover. I haven`t changed headlights, alarms, audio and etc. But I changed heater`s blower three months ago. I suppose that bug is in front of car, probably in engine bay.

Another sly detail: when bug appears ang key is inserted in ignition lock in any position driver`s side headlamp lights up, but passenger`s side do not. Simultaneously high beam bulbs light up too, but very-very dimly, although they shouldn`t light at all!

So I suppose the problem may be in front of passenger side, where are located AC kompressor, cooling fan relay and horn.

Goodday to you!
I haven`t found actual problem place, but I measured voltage from "+" and AC pipes - it was about 7.5V. Then I grounded AC metal pipe and car body by ignition wire. I know that`s not best solution but it works fine now!

OK.

This will be easier with a service manual - but what you need to do is find and repair/replace the chassis ground straps.

Albertj