Alternator with External Regulator

Gotta love that wiring . . .
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FordPrefect
Posts: 245
Joined: Tue May 20, 2008 1:16 pm
Your car is a: 1977 Fiat Spider 124

Alternator with External Regulator

Post by FordPrefect »

Alrighty.

So I replaced a leaky cambox gasket, along with the timing belt, and cleaned the terminal on my oil pressure sender, and topped off with fresh coolant.

Car ran great, took it for a drive yesterday, all gauges appeared to work fine, oil leak seems solved, so I was thrilled.

Today, when I started her up, I let her warm up for a bit and noticed the oil pressure gauge seemed to vibrate funny, and then the tach jumped to 6k while the engine idled with no change.

I turned the car off to check for loose wires and bad fuses, but everything seemed normal. Unfortunately, after this, the car refuses to run. I can start it, it turns over but refuses to idle, and if I give it some gas it runs a bit rough and still dies.

After poking around on these forums, my theory is that the alternator or voltage regulator is acting up. I have an older style alternator with external regulator on the driver's side.

Turning the key on doesn't light up anything on the dash, unless I actually turn the engine over, but I can't remember if it is supposed to do so. I plan on pulling the alt and regulator soon, but thought I'd ask if this sounds a likely culprit. Can I check either of these things in the car when the car doesn't run?
majicwrench

Re: Alternator with External Regulator

Post by majicwrench »

I really doubt if alternator is your problem.
Engine needs to be running to test alternator.
Look elsewhere.
Keith
FordPrefect
Posts: 245
Joined: Tue May 20, 2008 1:16 pm
Your car is a: 1977 Fiat Spider 124

Re: Alternator with External Regulator

Post by FordPrefect »

My repair manual says that if the charging light on the dash doesn't light up with the key turned to MAR, to check the alt, which is why I suspect it. Plus it's the only thing significantly altered after my recent project, I increased the tension slightly on the alt.
majicwrench

Re: Alternator with External Regulator

Post by majicwrench »

'm not saying your alternator doesn't have a problem. It may, or may not. I'm saying it is not likely the problem that is keeping the car from running.
FordPrefect
Posts: 245
Joined: Tue May 20, 2008 1:16 pm
Your car is a: 1977 Fiat Spider 124

Re: Alternator with External Regulator

Post by FordPrefect »

I got the alternator tested by a local alternator guy, and it all tested out fine. Funny thing though, after I put it back it, the car fired right up and runs.

Last question, when I put the key it and turn it to the ON/MAR position, no lights come on. Should I keep poking around until I figure out why? Maybe a bad light in the tach?
Adam

Re: Alternator with External Regulator

Post by Adam »

I had a similar thing happen with my car. It turned out to be a ground that came out of a clip near the drivers fender. Tach was all over the place, the car died when I turned on my signal light, it was pretty strange.
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