Finally found it, it was mounted on back of alternator. I swear I looked 20 times and it wasn’t there!

 

As I said, parts unavailable, any problems with it and its a paperweight, I have the case, just need a rectifier, there are none anywhere.

 

So nothing here would work for you?
https://store.alternatorparts.com/3g-rectifier.aspx

 

The regulator may be all you need to change. I believe there was more then one type of alternator with built in regulator so you might want to look at the Rock Auto site again to match up the part.
You can try just the regulator and most of the time that is the issue. I know one of them is easy to change without dissembling the alternator. If its the regulator then the alternator may run thousands more miles but you never know. IF I were on the road I would think about trying the regulator first (if you don't need to tear down the alternator to install it) and then look around for an old reputable auto electric shop that rebuilds them.
We had such a shop in town and it was a Sunday and I did not want to wait. 2 alternators later from big O store, I requested my money back and went to NAPA and bought a new one from then. If I had been a bit more patient, I could have taken my original FORD case alternator to the shop and had it rebuilt and upgraded for the same price I bought a junk one for!

 

He may show a 200 amp rectifier but he can't get it, I've talked with him personally, its why it says view, not order, the external stuff is quite expensive, I called the shop on the phone, had the part ordered for weeks before it came back unavailable and I was refunded. My alternator shop has been building them 20 years, the guy on that website has 40 years experience, it is safe to say there may be 200 amp 3g available, but there are no rectifiers being made anymore, so when they fail you are SOL. I do like the idea of external bridge rectifier, but $220 is out of my budget, the rectifier was $120 when available, the 130 amp only cost $35. I'm going to get back to it either this winter or next year, see if the 95 amp can keep up for now, I only have 2 amplifiers in the van right now, no more than 700 watts at the moment.

 

I have the 215a alternator, it has a special mounting bracket & belt in case you weren't aware.

 

Hi Marybeth,
Is it just the instrument panel lights that are out? The back lighting for the radio, wiper panel, HVAC controls, shift lever indicator, and instrument panel lighting all operate off of the same circuit.

My 88 and your 90 use the same headlight switch so though your van is a couple of years younger then mine, this wiring should be the same. If you turn the interior lights on by rotating the light switch handle all the way to the right, the instrument and dash lights go out and the interior cargo lights come on. I have noticed that if I just barely turn the headlight switch **** back to the left to turn off the interior lights, the dash lights will stay off. like there is a dead spot right there at that point. So if all of the dash lights are not functioning, try rotating the dimmer switch back a little from the far right position.

The fuse is #13 and is a 5 amp fuse. If that fuse is bad then none of the dash lights will come on.

If all of the lights are working except for the instrument cluster lights, then we can look at that issue. There are only 2 bulbs that illuminate the instrument cluster. it's not impossible, but very highly unlikely that both bulbs would go out at the same time. My cluster is only lit on the RT side because my LFT bulb has been out for almost a year now! I haven't replaced it yet because I need to replace my turn signal switch (won't stay locked in right turn position), lubricate my speed odometer cable which comes out from the instrument cluster side, and replace my ignition switch because the grease in it is very old and in the very cold days of winter, makes it hard to turn the key to the start position.
In your case though, it it is just the bulbs, I believe it was Mike1 who told me that you can access the bulbs by removing the radio and reaching back in there. That is so much easier then removing the instrument cluster!

The illumination bulbs are the 2 inner ones circled in orange.

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Here is a diagram for my 88 showing the dash illumination.

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So let me know which ones are out and we can go from there!

 

Start another thread or tell us here more about your home on wheels! My 88 is my daily driver right now and has been for the past 4 years. I have owned it a little over 6 years now. Helping folks with their vans here at FTE has also benefited me. While looking for parts, I often come across a Ford or Motorcraft part that fits my van and is much cheaper then a junk parts store part. Over time I have replaced almost all of the sensors on my van. Not because they were bad but because they are 35 years old. I keep the old ones in case of emergency.
I have found several ways to find parts and there are some part numbers that are for other vehicles but will interchange with our older vans. An example is my MAP sensor is actual for a Aerostar but is the same part for my van. I found the new Motorcraft MAP sensor for $12! Sometimes a seller might list a part by the number stamped on the part which isn't the part number at all but rather the engineering number. I have found a couple of parts ridiculously cheap listed by the ID number perhaps because they had not sold because they weren't using the actual part number.
So overtime I have been basically rebuilding my old van and keeping it dependable in the mean time.

What are some of the future issues you think you might have with the van?