So this is about my new to me 89 ford van. I'm about 1500 miles into it since purchased in Dec 2018. I had some cooling issues in the past week maybe some of the more experienced can comment.

We live in Miami FL. Two weeks ago I lent the van to my 78 yr old brother in law for the day. He had it idling with the ac cranked for about 2 hours. When I got it back, what had been a small water leak in the water pump was now enourmous. OK, brought it to the closest shop not wanting to tow or overheat (owner is acquanitance. $42 autozone water pump. $23 water temp sensor. I bought the parts myself, double checking on their database (hey I know autozone is a no no, but the alternative was having it sit in my brother in law retirement community. $250 labor for water pump install, water temp sensor and new air/cabin filters. Mechanic said they were the right parts.

Today was first day I drove the van since the fix. I drove it pretty hard this morning trying to get to homestead Fl for a bike ride. Averaged 65 70mph which works out to about 2600rpm with my 235/70-15 tires. Accelarator about 80% down, 10mpg. I have done that trip once before the water pump, no issues, a/c worked fine. Along the way, the a/c started blowing hot, when I got to my location, I could feel the grill and hood hot, the electric fan was running. Came back home more relaxed, 55/60 mph the a/c blew cold for about 5 minutes, then blew warm again.

Today was hot and humid about 90 degrees 80% humidity

Other probably irrelevant data... Since I had the van, both the fuel gauge and temp gauges have not worked. Today the fuel tank worked for about 4 minutes and the temp guage moved slightly, but never in the middle.

Not sure if I am going to bring it back to mechanic who did the work or go back to the people who have always worked on this van. Anything I should/could check myself in advance?

 

What engine do you have in your van?

The 89 did not come with an electric fan. The fan runs directly off of the fan clutch attached to the water pump.

When I had problems with my 88 with a 5.0 gauge, I went to the parts store and bought a 1 1/2" mechanical gauge and hooked it up temporarily. Its still there today! I removed the factory temp sending unit and installed the mechanical gauge sensor. Instead of going through the firewall, the gauge fit between the raised hood and the crowl at the wipers. It wasn't going to rain so I just stuck the gauge under the drivers wiper arm to hold it in place while I am driving and closed the hood mak9ing sure not to break the little sensor wire. that was over 3 years ago. My 5.0 has a 192F thermostat and the temp always runs around 191F to 195F and almost 200F if i am climbing a long grade on the interstate.

I had to replace the thermostat twice. You did not say if you replaced the thermostat or not?
If you are talking about an electric cooling fan for the radiator, then there has to be a temperature switch to activate it. I would check that. I am not sure what temperature the fan should come on at though. I replaced my original cooling fan clutch with a heavy duty clutch from NAPA. They make a severe duty but it is not recommended due to the stress on the water pump.

IF you have an electric fan, make sure it has some sort of fan shroud so it will draw all the air through the radiator. Make sure it is big enough to cover the entire radiator.

My 88 has the original brass/copper radiator so I also took it to a radiator shop and had them to clean it out. I can idle all day with the AC on and it never runs hot.

Does the oil pressure gauge work correctly?
The oil, tempature, and fuel gauge all work through a IVR (instrument voltage regulator) that is located behind the instrument panel. If it goes bad you will get erratic readings on those 3 gauges. The voltage meter is not connected through the IVR. It could also be separate issues in the wiring with each gauge. Do you have single or duel fuel tanks?
Often people use teflon tape on the temperature sending unit. The sending unit has to ground through the intake manifold where it is threaded in. sometimes the teflon tape may keep it from making a good ground.

As to the AC. I don't believe my 88 has a cabin filter, i need to check that... If it doesn't and they installed one, perhaps it is causing week air flow across the evaporator coil and causing it to freeze up. If the system is low on refrigerant the evaporator will freeze up.
If you have a 5.0 engine then my 88 and your 89 are almost the same. I believe the AC compressor has to come loose from the mounting brackets to replace the water pump. The AC lines can stay connected. If the mechanic removed the radiator to have more room to change the water pump, he did not need to remove the AC condenser.
If the ac was working just fine before the water pump change, perhaps the mechanic caused a leak in one of the AC lines or the condenser...

Do you know if your AC uses R12 or has it been converted to R134A? It should have a sticker if it has been converted. It would also have R134a adapters screwed onto the original R12 ports for charging and checking the high side.

 

thanks, lots of info... I have the 4.9 litre i6. Dual gas tanks. the fuel gage works for one, but not both tanks.. Good suggestions on the radiator. thermostat has not been replaced. I will get to it. Thx

jv

 

Well with the 4.9 you have more room in the engine compartment. With the v8's there is little room and the engine compartment as well as the hood get a lot warmer.

Since one tank is working then w snow the gauge is ok.
this is for my 88 but should be close to what you have.

 

I have seen a few cheap reman'd waterpumps for the 4.9L that had the impellors come loose on the waterpump shaft. So if nothing else seems to be the issue you may need to pull the water pump and check it. But like Annaleigh mentioned a aftermarket mechanical water temp is a great addition. It's really nice to know exactly what it's doing.