i recently installed a 91 model motor into my 87 and kept the 91 model aternator on the motor i installed and when i fired it up my mechanical alt gauge i installed does not read ?? it pluged right up to the 87 harness ! could it not be good ?? no alt light on the dash or nothing. and also my fuel gauge no longer reads on the dash cluster anymore and help would be appericated

 

so i got the alternator gauge working found some wires i didnt hook up. but still no gas gauge. i tried filling the tank about half way up in hopes that the float was stuck but still nothing. wires on tank look good n if i researched it correctly the float is a dealer item only so idk. i need some sugestions b4 i drop the tank ???

 

Perhaps you pinched or damaged the wires from the fuel sending unit in your engine swapping around.

Then they do fail last one i bought was a few years ago @ $120.00 if I remember.

 

Measure the resistance of the wires at the sender with the sender unplugged. You don't need to drop the tank to do this. Plug the sender back in and follow the harness where it enters the body right near the the passenger kick panel and measure there. Then measure at the connector that plugs into the instrument panel.

Best to do this with the instrument panel unplugged as it can mess with the resistance. Use the FSM to determine what wires are what on the instrument panel connector.

The stock sender is about 3ish Ohms when full and 103ish when empty. You should be somewhere in the middle.

 

As always, The Good Book provides the way:
http://personal.utulsa.edu/~nathan-b.../6combinat.pdf

The sender is about $70 (you need your VIN; the part depends on the size tank you have). http://www.toyotapartsoverstock.com/...332080117.html But you can determine if the sender is the problem without opening the tank.

 

thanks guys u saved me alot of work. so ima try it out and see what happenes. and if i do need a sending unit that one in the link is for a fuel injected motor. mine is a carb base model are they the same?