Just Bought 86 Lx

See http://slantnosefox.com/picturehosting/jeremy/86 electrical & vacuum troubleshooting manual.zip you can download the whole set of electrical troubleshooting and diagrams for an 86 Mustang courtesy of Jeremy, AKA V8only.
It is a big 61 MB download that you get to unzip and save on your computer. It may take some time to download it, but the results are worth your time.


Speedometer gear help: See https://lmr.com/products/Mustang-Speedometer-Gear-Calculator

Tl619lt said:

Hi, new to the forum! Yesterday I bought a nice condition notch (rate on the east coast). Brought it home and decided to change all fluids. On the ride I noticed the temp gauge never came up at all (cluster gauge, most factory ones don’t work)..... tried to vent the radiator and was met with lava hot poo like liquid!!! So I drained the radiator, and began to replace the thermostat.... Called seller, obviously never had an issue...... but said “there’s no need to replace the thermostat, I have a 115 degree in it”.... with an electric fan w/o thermostat settings..... replaced it with a 195 and wouldn’t you know it, the lower bolt was stripped out!!!! So I changed all other fluids and had to tow to local shop to handle the thermostat issue and fix a VERY rich carb...... flushed the entire cooling system, but what’s next? Car looks amazing and is in great shape. Questions I have:
1- how to fix the stock gauges?
2- heat fan does not blow? Blower, switch, or resistor?
3- correct speedo gear for 373 gears?

Thanks for the read and help, sorry for the long post, Nick!

Click to expand...

welcome.

A few things

86 are EFI. If you have a carb I suspect someone converted it over. which is a red flag to me. Did they do it right? What distributor, EEC, etc.
The stock gauges are notorious for being inaccurate and not working- for the water temp gauge do the following troubleshooting
disconnect the wire from the sending unit which is right behind the distributor on the lower intake by cyl # 5 and ground the wire. Turn the key ON but not running. You should see the gauge spike all the way to HOT. If it does, the wiring and gauge work and you need to replace the sending unit. $10 par and an easy repair. Drain some fluid and replace the sending unit. If the gauge doesnt move when you ground the wire, take a test light and check the sending unit wire for voltage. You should see the light pulse, that will mean the IVR works, if you get no light or pulsing, the gauge is bad, I would also check to make sure the ground from the back of the motor to the firewall is there and connected as that acts as a ground for the gauges. Most Likley its the sending unit. Make sure you don't put teflon tape on the new one or it will ground it out. They should come with pipe dope or tape already on them.