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I picked up a 1995 gas cluster with tach (always wanted the upgrade). $40 steal. At the very least was gonna use for the calibrations. It has 6, CAL is set to 9.18
I noticed on my old dash I had taken the bulb out of the ABS warning light. That’s actually on with a Code 12. I’ll visit that later.
New cluster in. Test drive. Almost dead nuts! At 40-45 it’s starts to show a bit slow. At 50 on cluster, it’s 48. I’m sure 904 as we discussed, would be dead nuts at all speeds.
So it was the old cluster. Here’s the deal, I have taken all the needles off. I was noticing today that the old speedo is slow 10-12 mph at all speeds.
I know the fuel needle HAS to be put on exact. Perhaps the speedo is the same way...maybe I just simply put the needle on wrong.
well on the bench you could apply a Known VSS signal to the PSOM and then stick the needle on at that Calibrated speed. I seem to remember you could apply a 1.5 VDC signal to the Meter Movement and it would drive the meter movement to 70 MPH BUT I don't recall if that will work for a PSOM Movement.
as I said before these things are old and made during the time of the "90's Capacitor Plague" so replacing the Electrolytics is a prudent idea.
Anyway Glad ya got one working so that we know we ain't Nucking Futz
the ABS code 12 should be simple enough .. Brake fluid level switch, the Vacuum switch on the diesels and sometimes bleeding the Valve and back brakes, Big problem is most folks don't change brake fluid when they should...... it's as bad as the Differential Oil change, most don't bother until there is an issue.
well on the bench you could apply a Known VSS signal to the PSOM and then stick the needle on at that Calibrated speed. I seem to remember you could apply a 1.5 VDC signal to the Meter Movement and it would drive the meter movement to 70 MPH BUT I don't recall if that will work for a PSOM Movement.
as I said before these things are old and made during the time of the "90's Capacitor Plague" so replacing the Electrolytics is a prudent idea.
Anyway Glad ya got one working so that we know we ain't Nucking Futz
the ABS code 12 should be simple enough .. Brake fluid level switch, the Vacuum switch on the diesels and sometimes bleeding the Valve and back brakes, Big problem is most folks don't change brake fluid when they should...... it's as bad as the Differential Oil change, most don't bother until there is an issue.
So my brake light won’t self-check, nor will
it come on with the parking brake. Bulb is good.
Tested that my brake lights actually work. Good.
I jumpered the plug for brake fluid level switch and the brake lamp on cluster proved-out on startup. Also tested the ground of same plug for continuity with engine ground, and it’s good.
Parking brake will not activate brake lamp on cluster. So I’ll get after that next.
So so at the very least my low fluid switch is done? Doesn’t look like that’s replaceable without swapping the entire reservoir.
I really need to find this resistor/diode assembly but it’s wrapped in the harness somewhere. My wires are so faded...I should be able to do an ohm test and get resistance in only one direction...
that switch unplugs from the Reservoir after you remove the connector there is still some tabs holding the actual switch in ... I just had one apart a few weeks ago.
that switch unplugs from the Reservoir after you remove the connector there is still some tabs holding the actual switch in ... I just had one apart a few weeks ago.
Wait. So it’s serviceable? I just tested all wiring. Definitely a bad fluid level sensor. Also the parking brake switch is intermittent. I tried cleaning the contact washer and points it rests on. Still intermittent. It’s such a simple contact switch. SMH.
the Level switch isn't exactly what I would call "Serviceable" at least not by the service manual standards, it is replaceable, and one can repair it. ... it's a magnetic reed switch and not too hard to find one in a Junque Yard.... they often fit in pockets while looking for other parts BUT you didn't hear that from me... they only charge you some change for it at a Pull-A-Part
Learning more by the minute. Seems as though I could just get a reservoir kit for about the same. How does it work? Does it involve the float having steel on the bottom of it and when fluid is low it attracts to the magnet?!?!
yeah the float has a magnet.... and when the level get low the magnet gets close to the bottom of the reservoir and trips the switch...
you can generally connect your Multimeter set to the Low Ohms scale or Continuity Range... and press the float down with a wooden dowel and watch the operation of the switch.
Btw, I moved the needle on the speedo module. On the bench, I set it face up (supposedly that’s a no-no). I held the end at a certain mark, then pulled the needle up and off, then moved it 10mph higher. Speed is almost dead on. It’s 1-2 fast at lower speeds, and about 4-5 off at 50.
I GPS’d my mileage counter. Seems to be dead on, over the course of 5 miles.
This, again, is the old speedo. I’m still inclined to go with the new one, but maybe if I get this dialed, I can resell the whole unit with a clear conscience. I want my rpm gauge lol.
Another easy way of setting the needle correctly is to plug the cluster in, without the clear housing on, turn the key to on, then set the needle on the PSOM. Just light enough that it stays put. Then if your comfortable, you can press it firmly in place.
Supposedly it can be done while the engine is at idle. I didn't go that route, but I'm sure you can.
So attempting to set the needle perfectly, I have a feeling those 2 little dots around zero have something to do with it. The needle driver does move when ignition gets turned on. I’ve got it to where it’s off maybe 1mph at 30, and maybe 2mph at 60+. Although I’m happy,
sidenote. While I was clocking the needle, I had the “cap” off the needle base. The needle was bouncing heavily at all speeds. Perhaps the bouncing speedo issue could be resolved by adding some weight (in the milligram range)....
