Intermittent alternator issue
- Thread starter MM3846
- Start date
I found that info in the dweb catacombs, but went with the 95 one bc I didn't want the tach "issues"
Stupid suggestion, only because all charging starts with the belt, forgive me if too fundamental, is the belt routed correctly? Not that you have these symptoms, but it is the first step.
No worries. It is routed correctly. It was too cold and I'm too sick to do anything but unhook the battery. Battery was weak again leaving work today, alt started charging once I left work and turned on the main road.... maybe 1/4 mile and 60 seconds. I'll see how it starts tomorrow AM.
T/S For Tach
May want to try troubleshooting the tach issue and could find fault causing the alt issue. Phase Tap Resistor?
......
May want to try troubleshooting the tach issue and could find fault causing the alt issue. Phase Tap Resistor?
......
there are no tach issues when you swap the pulley, well except for the bosch replacements that don't seem to last as long as the original
I'm on a mission now to fit a 145 amp delphi AD244 on mine, but thats overkill for fixing a non charging alt.
Or are you having a weak battery to begin with? That is why the voltage is always low at the first few minutes you start the car, and as your alternator is able to charge the system, so the voltage jump back up to above 13V.
After you gets home, check the voltage without the engine running, shut it off, unhook the battery. The next morning, hook it back up and check the voltage again without the engine running. See if there is any voltage drop.
After you gets home, check the voltage without the engine running, shut it off, unhook the battery. The next morning, hook it back up and check the voltage again without the engine running. See if there is any voltage drop.
I haven't done that, but every morning I'm seeing at least 12V at the battery before starting. I had the battery disconnected last night, and started it again this morning and it seemed the same, so maybe I'm just not used to the slow(er) starts in the winter. I have a permanent volt meter hooked up, so I creep around after startup at 11.5-8 and then out of nowhere after a minute or so it jumps to 13.8. Maybe the battery is shitty even though its new.
I'm probably taking half a day at work because I feel like shit. I'll do some wiring on the truck when I get home and then see what happens tomorrow.
Ok, put new ends on both small wires and cleaned up the charging wire+terminal at the fuse box. The small wire ends seemed ok, not bad enough that I would immediately say they were the issue but they were definitely showing their age. I didn't have an end that would fit in the fuse box for the charging wire so I didn't change that. Also removed the body ground at the radiator, cleaned it really well and scraped some rust and shit off.
Started and jumped right to 13.8V but thats what happened when I left work today too. We'll see what happens tomorrow since the truck is going to sit a while.
Started and jumped right to 13.8V but thats what happened when I left work today too. We'll see what happens tomorrow since the truck is going to sit a while.
No change this morning. Ugh. I did notice sitting at stoplights that my voltage will slowly drop... then come back up as soon as I start driving again. I didn't notice this when I parked at work since the truck revs another hundred RPMs or so in park.
So what's the best bet? Warranty the battery or alternator first?
So what's the best bet? Warranty the battery or alternator first?
I have this same output on my truck's alt. 13.6V all the time. I replaced the regulator/brush assembly after a wire harness short.
I suppose it could be a diode but it is always 13.6V.
It may be unrelated but I recently installed a reman Bosch unit on my 740iL. It does something very similar like the sensing isn't quite right. Starting the car goes down to about 12.2V (it has a VERY large battery) and sits there until first throttle tip in. Above idle the voltage jumps to 13.9V then settles in at 13.7-13.8. Occasionally I'll see the behavior when there is a medium load (lights only) but not when it is unloaded (normal running) or heavy load (AC, audio, lighting, etc).
I wonder if this is a Bosch thing.
This is interesting. I have been interested in an alt upgrade because I want to put some additional lighting on my truck.
The phase tap looks simple. Is it only a single phase? If so that means any alternator with the same pulley diameter (to retain the ratio between the crank pulley and alternator - otherwise pulses per RPM would be high or low) could be tapped to drive the tach. Otherwise you'd need a pulse generator to run it (tap the flywheel VR sensor?).
I guess I can put a scope on it and see what the output looks like but it is likely someone has done it before and the info is buried in the forum somewhere.
its not just the pulley ratio, its also the # of "loops" the stator has that will change the pulse per revolution. Ad244 is the same as the D1 alt so amplitude is the only concern and the phase tap resistor can be changed if necessary like you said
oh and the ad244 has the same taper as the d1 pulley so you just swap your old one over
oh and the ad244 has the same taper as the d1 pulley so you just swap your old one over
Ah, yeah. Forgot about that. The number of claw poles in the rotor windings makes a difference in the pulses in the stator. I suppose that could be compensated by a pulley change but a matching alternator would eliminate the fuss and be a largely mechanical fitment. Sounds like that is the direction you are going.
