Battery problems?

smooth_eddy · smooth_eddy's Garage

I am having trouble starting my 914. The battery acts strong at times, then seems to have troubles other times. It acts up both when it is hot after a long trip and when it is cold too. So I don't think it is a hot start relay problem because it will fire up right away with a jump start.

I checked the voltage reading at the battery with a Fluke meter at idle. At an idle of 1000 RPM, I read 13.83 VDC with all accessories off. With everything on, idle drops some but still reads 12.35 volts at the battery with my Fluke. I think this is still acceptable? I do not know the age of the battery but it looks okay. All the terminals are clean, tight and corrosion free. Should I start by replacing the battery?

dimmer · 09-27-2004, 07:56 AM

Check your fan belt and make sure it is really tight. I had the same problem.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

How's the voltage at the yellow wire to the starter when you're trying to crank it over? (Most especially when it isn't cooperating.)

--DD

smooth_eddy · smooth_eddy's Garage

I can see the alternator belt tentioning nut, but how do I get to the fan belt to check the tightness? is it accessed from below?

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Nope. Just reach around the front of the fan shroud, you should be able to feel the belt.

--DD

smooth_eddy · smooth_eddy's Garage

Thanks Dave...

I checked the belt and it has about an inch of play in it. I will tighten it this weekend. A slipping belt would explain why I have intermittent problems. Sometimes it grabs and sometimes it slips, which would prevent my battery from charging.

bd1308 · 10-03-2004, 06:06 AM

wouldn't the red light come on if it wasn't working??? or does that just show internal faults within the alternator....

smooth_eddy · smooth_eddy's Garage

I ordered an Ultima 34R battery and it showed up yesterday. I will put it in after work today. The car barely turns over with the old battery when I start it. I am not sure of the old battery's age. With the properly tightened belt and the new battery, hopefully this will take care of my electrical problems.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Clean up the ends of the ground strap on the transmission. Both ends, the trans end and the chassis end. Also clean up the battery cable clamps while you're at it. And maybe the attachment from the battery ground strap to the chassis, too!!

Oh, and wash the battery tray and everything below it with a baking soda/water solution. Repeat until it stops foaming, then rinse liberally with water. Now that you won't be dripping acid down onto it any more, you want to neutralize all the acid that's there.

--DD

smooth_eddy · smooth_eddy's Garage

Thanks Dave... those are all good tips. I will follow your advice and clean all the grounding points you listed above. Grounding seems to be a big issue with these cars. I do get some stange electrical things happening at times. It will be interesting to see if this helps any.

Conrad W Peden · Conrad W Peden's Garage

I'm not too sure about the 'really' tight alternator belt advice.

A belt that is too tight can put undue stress on the alt. bearings and shorten its life.

A good belt that is the right 'tightness' will suffice. Your loose belt maybe polished and worn so getting a new one might be a good idea.

How do the rest of you guys tighten tour belts? Been about 5 years since I've done mine cant remeber how I tightened it.

smooth_eddy · smooth_eddy's Garage

My belt is kind of a cog type of belt. It felt fine but I was not able to actually see it. I had over an inch of slop before I adjusted it. Now I have about a half inch which is What Haynes recomends.