Hey guys I have a 1994 Honda Prelude, with a H22 motor and after doing a rebuild I have been running into a lot of electrical issues....

1st: My temperature gague ALWAYS reads over heating even when it is not... i have replaced the sensor 3 times now with a new one... it works the first time i start the car but 10 min later it tachs out ... any ideas???

2nd: As I drive my speedo and tach both basicly shut down and fall to 0 on both. and then will bounce up and down but stays consistant with my speed.

3rd: When I hit my brakes, or turn on my turn signal, my radio and tach both freak out ... radio shuts off and tach does what i said above...

4th: My windows roll up and down like a snail on a hot day. and lights all dim when using anything in car. turn signals, headlights, etc.....

we have tested both battery and alternator numerous times and they both check out everytime.....

if anyone has any clue on what is going on please let me know or what i can do to fix or figure out what is going on... even a shop cant figure out whats going on ... please help me and them!!

thanks ....

 

bump

 

I know you said you checked it, but my best guess is that the alternator is sending out bad voltages, either try using a different alternator, or use a multimeter and check your voltages, that's what I would try first, make SURE it's not that. It definitely isn't your battery. It potentially could be flooding in a fuse box or something... although I doubt it. My alternator was getting a bad connection to the + wire, and I was getting the same problems with the speedo, pressing the brake and the radio going out, slow windows, dim lights, all that. It's because the voltage is too low.

 

Put your multi meter on AC volts and let us know if you have any AC volts coming out of the alternator. I think that you dont have something grounded very well or you have two identical plugs (connectors) that are plugged into the opposite connectors plug, for example two green plugs or two grey plugs that are the same and can reach each other and they are backwards.

My first step would be to list all the affected items like you have and see if they are all related someshere on the diagram, maybe they all share a ground circuit, MAYBE.

The speedo and tach both go to the ECU but their inputs are seperate items, VSS & ignition coil. The door windows should no be related but who knows, just did a Nissan, door items affected, entire guage set affected, would not come out of gear, no small lights (headlights ok) many things didnt work, the car started no problem, the main fuse 80 amp was intermittent, ever see an intermittent freakin fuse. I found the problem after studying the wire diagram, couldnt believe it, tested good with a meter but wouldnt carry the actual load, fuse was blown but was still touching, looked and continuity tested good just couldnt carry heavy current.