Honda Prelude Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
566 Posts
Discussion Starter · #1 · (Edited)
So today I tested my coolant temperature gauge sender which required disconnecting the wire from the gauge sender. As soon as I removed the wire, the battery charge light on my cluster stopped lighting up during cluster bulb test. And now the battery charge light sometimes turns on when I start the car.

Without knowing what led up to this problem, the symptom looks like a slipping alternator drive belt, but its not. This problem started when I disconnected the wire from the gauge sender so this is somehow the cause. Also, I tested the voltage at the battery when the battery charge light stayed on and I got stable 14.32 volts, so the alternator's working.

I currently have a problem where my gauge sender is sending incorrect readings that my car is at normal operating temperature when the ignition is turned on and the engine is cold.

Previously I had an alternator regulator problem where the alternator would sometimes charge but then just stop. On one or two occasions, I saw strange behaviour where the gauge would shoot up to hot when the temperature was normal and then come back down to normal as soon as the alternator stopped charging.

Its looking like a short circuit if you ask me... in the engine wire harness or the cluster. The regulator has a circuit going to the cluster which energises the battery charge light when the alternator has a problem.
Schematic Rectangle Font Slope Parallel

Product Font Rectangle Parallel Slope

For some reason, the bulb check circuit is missing in the wiring diagram for the 1990-1991 models which my car falls into so here is the 1988 model wiring diagram which contains it.
Schematic Rectangle Font Slope Parallel


I'm just soooooo over this car. My life is going by as I fix one problem and then another stupid problem develops.

My head is hurting, please help.

Here is a video of this pathetic theatrical.

https://filesharing24.com/download-...wmQoCB6uD5JUgnWnb4FcGyUZb9DDg36FpmoLr6Q%3D%3D
 

·
Registered
Joined
·
566 Posts
Discussion Starter · #3 · (Edited)
Oh yeah, the A/C compressor control unit is also in the battery charge light circuit but I don't think its causing the problem because the control unit only grounds the circuit when there is a problem (I believe).
Schematic Slope Rectangle Parallel Font

The alternator should be grounding the circuit when the key is turned to ignition but that doesn't appear to be happening, but then it sometimes happily grounds it when its actually charging. Ridiculous.

I'm wondering if I have a short to power between the coolant temperature gauge sender and the alternator L circuit. They both run together in the engine wire harness, through the under-hood relay box to the dash fuse box. I recently stripped most of the engine wire harness and didn't find a problem.

I'm going to go outside now, pull the gauge fuse, activate ignition and see if the coolant temperature gauge sender wire is energised...
 

·
Registered
Joined
·
566 Posts
Discussion Starter · #5 ·
So I've just been outside. Got 10.67 volts on the coolant temperature gauge sender wire and then nothing once I pulled its fuse, so that rules out it shorting. Problem persists.

Another thing I just noticed... usually when I turn the key to ignition, I hear a chirp coming from the engine bay. I'm not hearing that anymore.
 

·
Registered
Joined
·
566 Posts
Discussion Starter · #6 ·
Unfortunately the service I used to host my videos is another fucking pile of horse shit crap. I was told they would be valid for 24 hours and yet they are already gone. Just more dumb fuck 'I.T. experts' that should be shot.
 

·
Registered
Joined
·
566 Posts
Discussion Starter · #7 ·
This is actually a really great car. Noobs like me come along and hose down their engine without covering the alternator, not realising its still connected to the battery. The problems I'm having with it now are caused by junk aftermarket parts. If I had $400 for a new OEM regulator from hondapartsnow.com, this drama would not have happened.
 
1 - 6 of 6 Posts
Top