Tech Tips @ A review of the core returns show that more than 50 percent of all the pulleys we supply on alternators are being returned on the core. This indicates that our customers are having to change most of the pulleys. Because this relates to Ford and GM _ automotive alternators, I now understand why most of the large rebuilders do not install pulleys on these alternators. Since the old alternator has the correct pulley on it now, and at best we are relying on someone’s idea of what is correct, we will supply and install pulleys only where we can be absolutely sure that the pulley is the correct one. @ A Ford TSB reports that on 1990 to 1992 Ford Probes, the malfunction indicator light (MIL) may come on intermittently. They say that this may be caused by output voltage variations from the EGR valve position sensor (EVP), as a result of carbon deposits on the exhaust gas recirculation (EGR) valve. If the symptom sounds familiar the repair procedure is found in TSB 95-3-5. HM According to Motor magazine, some late model Fords equipped with the 3.0 and 3.9L engines with the dual oxygen sensors may seem to set “keep alive code 176” (front 0/2 sensor lean). The customer will probably not notice much in the way of driveability problems, and may report that the check engine light comes on sometimes and then goes out. First determine that the sensor’s heater circuit is functioning normally and that the output voltage is cross- counting swiftly. If this is correct, you are left with about 20 potential causes and where to start. Motor suggests this little trick: swap the 0/2 sensor front to rear. They are identical except for the length of their harnesses. If the ECA memory now shows a “keep alive code 172” (rear 0/2 sensor lean) the problem has moved with the sensor and it is definitely pooched. If the code 176 comes back, there is an inter- mittent lean condition on the front back. M@ Another Ford TSB, covering early 90s full size Ford, Lincoln and Mercury products indicates that an intermittent “no start’ may be caused by corrosion in the wire at the switch terminal at the solenoid. This is the solenoid on the starter, not the control solenoid on the fender. There is a long detailed repair procedure which basically involves removing the switch connector and about eight inches of the wire and replacing it with new. @ I have good news and maybe some bad news; General Motors has stopped equipping cars with the CS130 alternator. This is the alternator that first suffered from rear bearing failure, then from front bearing failure (almost always caused by a bad tensioner), and always from a short life span, which I believe is the fault of the car designers who do not understand or care about the alternator’s need to cool itself. And why should they? It almost always outlasted the warranty. Delco has now brought out the CS130 DIF (dual internal fans). While the alternator is called officially a CS130DIF, everyone but the engineers will refer to it as the CS130D. This alternator started making its appearance on some 1994 vehicles and will soon be the alternator of choice for GM. As the name implies, there is no external cool- ing fan, and it is not necessary because the unit has two on the inside. There is a very heavy battery post sticking straight out the back, and on all models seen so far, the entire back of the alternator is enclosed in black plastic. On some models this plastic cover has holes and/or extrusions for attaching breather vents. This alternator uses the same electri- cal connections as the CS130, but the regulator plug was redesigned and will not interchange with the CS130. The plug was redesigned to make a better seal to prevent corrosion from forming on the regulator pins. In my personal experi- ence, this has not been a major problem, so the purpose behind the time and effort put into the redesign eludes me. The alternator appears not to be read- ily rebuildable and will probably be much more expensive when it comes time to replace it. Since I have already heard that there are some problems relat- ed to the rear bearing and a short life span, I question if the first few models are going to be much of an improvement. Could this be another case of a change for the sake of change? One feature of this alternator that could lead to some problems is the regulator’s temperature sensor. If its internal temperature reaches 280 degrees F, it will shut down and turn the idiot light on. A while ago, I read an article which indicated that the under hood temperatures of modern cars was approaching 270 degrees F, which doesn’t leave much room for error. Suppose it’s 95 degrees F outside and you’re stuck in stop and go traffic for about two hours, with the air condition- er running full tilt. The idiot light comes on, telling you that the alternator has stopped charging. What’s happened? The regulator has reached its thermal shut down point because of the prolonged period of idling (inability to cool), with the