TR4/4A Generator Light Turned on While Out on New Engine Build Drive

[KVH]

That's why it's so much fun. So, maybe one of you can pinpoint my problem. Here's what happened: Left Headlight kept flicking on then off; rather noisy front engine sound seemed to be coming from the pulley fan extension or from the generator--I really couldn't tell. While debating the subject my left headlight went out again and my generator light came on. Any clues what's wrong? Bad generator? Bad headlight?

About that pulley fan, I didn't install the balance weight because even Moss told me to use "only if needed." I see a tiny little wobble in the extension piece but I'm reluctant to conclude there is a balance issue unless one of you has a feeling that "noise" up front could've been the fan. To me, the sound was like a whirling sound of a bad brush or other pulley, fan or belt problem, and not likely to be from a balance issue, and I'm also assuming that modern manufacture is more likely to be accurate on fan balancing, but I'd like to hear what others say.

thx

 

[TR3driver]

Take the belt off and run it briefly. My guess, the noise will disappear, indicating it was in fact the front generator bearing. The good news is they are easy to change, although if it's never been changed before you may have to drill out 3 rivets and replace them with sheet metal screws.

Headlight problem most likely something else.

Just out of curiosity, which fan do you have? Not relevant, I'm just curious (nosy).

 

[KVH]

I put a new steel four blade fan on the extension. I wanted it stock and I prefer to be able to grab and pull the fan to time the car, set valves etc. Let's say that I have a bad ground on the left headlight--would that cause a voltage disparity that would flick on my red ignition light?

 

[TR3driver]

I put a new steel four blade fan on the extension. I wanted it stock and I prefer to be able to grab and pull the fan to time the car, set valves etc. Let's say that I have a bad ground on the left headlight--would that cause a voltage disparity that would flick on my red ignition light?

No, it shouldn't. The red light basically can only come on (from being off with the engine running) when either the generator stops generating (current starts flowing backwards into the generator), or there is a problem with the control box or wiring to the generator. In effect, the light comes on to indicate that the cutout contacts have opened (otherwise the contacts short the light out), and variations in load should not cause that to happen.

In my case, when the bearing failed, I heard it making noise on the way to work and the light blinked a few times. When I tried to limp home, the red light went out at first, then flickered off and on for awhile, then came on solid. Shortly after that, the belt started squalling and I pulled over to wait for a flatbed. Post-mortem showed a lot of rust in the old bearing, and the few remaining balls were more square than round. But new bearings (and some repair work to the mounting holes) fixed it right up. In retrospect I probably should have replaced them as a matter of course. But as usual, I was operating in "no time now to do it right, but time later to do it over" mode.

 

[trrdster2000]

KVH, check the bolts holding the bottom belt pulley together. It's a two piece pulley and I have seen the bolts come apart and wear the holes oblong, made a heck of a racket in the final stages before we found it. The light may well be the bearing as Randall says.

Wayne

 

[Geo Hahn]

You might also grab the generator and see if it is at all loose. There are a couple of bolts, a part that can break and a threaded fitting that can get wallowed out -- any of those can be bad for the bearing which is bad for the generator.

 

[KVH]

This is a first for me. Shop says I burned the bearings out with the pulley too tight. I'm not recalling that I applied much pressure, but they're right about the bearings. One was all ground up, and the other so bad it shorted against the housing and actually ruined the housing. The good news is that this great little shop circa 1960 is rebuilding it, and it will be as good as new. Maybe one day I'll consider the alternator conversion.

 

[TexasKnucklehead]

The generator belt can be much looser than an alternator belt. I wore out a few of the bushes in the rear of the generator before I realized how loose it can be, and still function fine.

 

[KVH]

The generator belt can be much looser than an alternator belt. . . .

Yes, definitely. That's what I'm being told. BTW, I'm fairly certain that at night with a flashlight I was seeing specs of the rear bushing being ground off into dust.

 

[TR3driver]

BTW, I'm fairly certain that at night with a flashlight I was seeing specs of the rear bushing being ground off into dust.

Could be, but the rear bushing is bronze which usually doesn't make sparks. However, a certain amount of sparking can be seen on the brushes at night.

Personally, I'd dubious of the "belt too tight" theory. That front bearing is a big ball bearing that should be able to handle lots of side force, bigger than found in most alternators. The rear bushing isn't as strong, certainly, but also gets very little of the belt tension due to the long lever arm between the front & rear bearings (compared to the short lever arm between the front bearing & pulley center).

But, when was the last time you lubed those bearings? The rear bearing is supposed to get a few drops of oil every 6000 miles, the front one repacked every 20-30,000 miles.