I'm not new to this forum but since I have little to offer I usually only come when I can't figure out my Honda's trouble. Hope someone can help me out. I have searched so i hope i did not miss the solution.

1990 Accord LX. 4 Door, AT. 240,000 miles.

Historical Symptoms.
Charging light comes on and off randomly for last few years.
Tach will usually not come on right away when i start the car. It will "jump" on long after the car is started.

What i have done.
New Battery, Tested the Alternator and it was good. Checked the fuses.

Electrical Repairs I have done myself in last 12 months.
Replaced the switch in the shift assembly that locks out your ignition.
Re-soldered the main relay to fix typical "hot day" starting trouble.
Removed and had alternator checked.
New Battery.

Possible Irrelevant info.
Radio was stolen a few years back. I had to pull the whole dash to replace the dash bezel. At that time i installed a dummy alarm LED light that flashes when car is not on.

Twice now i have run the battery down so that the car quits. Electrical systems start to turn off like the radio or lights. Car has trouble shifting and when i turn her off it will not re-start. Dead Battery. First time it took a few years from when the charginglight started acting up to the time it died. This time it took a few months. Seams like the charging light comes on and off more frequent now but that may just be my imagination.

Literally, the charging light comes on and off ***** nilly. Can not make heads or tails of what makes it do that. Nothing consistent like applying brakes, accelerating, turning on or off lights, radio, etc. No amount of time between when it starts, stops, comes on or off. Tach may or may not respond when i start up and no correlation between the two.

Looking at this post for possible help.

https://www.hondaaccordforum.com/m_86848/tm.htm

Thank you for your time

 

the tach points toward the coil .... any problems with how the engine runs? What kind of spark plugs do you have?

 

It's possible that a regulator in the alternator is going out, meaning it will work fine for a while then give you issues so it would test just fine.... The tach is most likely a vss issue or a loose connection.... will the charge light ever flick on when it's just sitting and idling? if so get a voltmeter and test output at the alternator when that comes on. is your belt loose at all?

 

Update. Put a new battery in and everything works fine. Not surprising since i know the old battery was dead. Drove home fine but noticed the charge light did not come on. Turned the ignition the first click and i believe the charge light should come on before the engine starts. I may have lost the bulb...

Falkore,

Asside from what i consiter poor gas mileage the engine historically rans fine. The last 3 or 4 days i have had high idle in the morning that would not kick down for about 10 minutes. That is new. It can also idle a bit low every once in a while but otherwise gives me no trouble Spark Plugs... No idea. I've never replaced them so i bet stock.

Sir Nasty,

Since the charge light is not coming on right now i can not tell you about it's status at idle. Seams to me that it would happen at idle and at speed. Belt is not loose.

I will try and pull the codes next but since i just replaced the battery i am sure the memory was erased as well. Will report.

Going to check the ELD as well. Found the 3 wires and they look solid but stiff. Connector seams OK.Will check it with this i found in this post.
https://www.hondaaccordforum.com/m_95135/tm.htm

"You should probably also have the ELD (electronic load detector) circuit checked . The easiest way ive found to do this is to unplug the green/white wire in the 4 wire terminal in the back of the alternator, reconnect the plug to the alternator and see if you have a charge.If not alternator, if it charges either a fuse is blown or you have a bad ELD circuit."

Thank you for the assitance.

Matthew

 

OK. Tried to pull codes. With the service plug NOT shorted the check engine light goes off after a few seconds. With it shorted it stays on. No blinking. Charging light does not come on at all. Never.

Pulled the dash and verifed the bulb is fine. (May have messed up my temp sensor in the mean time as it now reads red hot all the time. Will look at that later....)

Haynes ran me thru some tests. Disconnect the neg battery terminal and jumpered the terminal with the negative cable with a light bulb. Light is on. Suggests a drain and to pull each fuse till it goes out. The only fuse that caused the bulb to go out was the 80A battery fuse. Mean anything?????

Pulled the alternator plug. Verified voltage between Blk/Yellow wire and ground. Shorted Blue/White amd verified dash bulb went on. Checked Battery voltage. 12V. Started engine and voltage did NOT increase. Looking at alternator or ICU next per Haynes. It suggest to look at ELD next.

Matthew

 

Checked the ELD.

12V between outer pins when plug is disconnected. (Black and Black/yellow). Ignition off

4.5V between Red/Grn and Black with plug removed and Ignition on.

1V between ground and Red/Grn with ignition on and headlights on. Haynes says this should be "about 2V". If it is not it says to replace. I have also read this might cause the intermitant charging light. Is this my smoking gun as far as the light goes?

Still trying to figure out why the charge light will not come on at all.

Matthew

 

One possibility that caused me a lot of griefon an Acura 2.5TL (similar to an Accord) and has similar symptoms: battery goes dead and Alt light does not illuminate. After a lot of grief, the harmonic balancer/crankshaft pulley rubber isolator was slipping, literally causing the pulley to slip relative to the engine from the load. preventing the belt driving the alternator. When you're at idle or cruising, apparently the system is charging just enough tokeep the Alt light off, but not enough to keep the battery from eventually going dead. It's not clear why the Alt light would not come on when load was really heavy; lights, AC, etc, but that's what happened, not once but quite a few times before problem was finally recognized.

Bottom line is check your harmonic balancer by marking a heavy radial mark w/ a black marker across the outer pulley and rubber isolation ring and see if the inner/outer part of the mark start to separate. You'll have to drop the lower dust shield down to access the harmonic balancer(about 5-10 minutes to drop and same to re-install).

Note, replacement of the harmonic balancer requires removal of the crankshaft pulley bolt and careful installation to get balancer engaged to timing belt drive pulley and crankshaft (woodruff key link). Make a mistake and you'll be buying a rebuild of the valve train or a new engine due to mistiming.

Because your battery is not retaining charge, somehow it's discharging; either while you're driving or while engine is off (some drain that should not be there?). Worth checking for a battery current drain when everything is off w/ a VOM meter measuring system amp draw (series connections) to battery cable.

I suspect the tach problem is not related to the battery dying. I've seen bad coil, ignitor, and spark plug wires cause tach bouncing. Coil is most likely culprit, followed by spark plug wires.

good luck

 

Update.

Alternator was no good. Replaced it and charging light is back on. Some good news. Checked voltages under load and everything is OK.

So. Currently i still have the temp sensor that is reading red hot all the time. Took the cluster apart again and nothing seams out of the ordinary. Put voltage to the screws/leads and it behaves fine but in the car it is always hot. Will monitor.

Would like some input on the 1V i am reading on the ELD.

Matthew

 

does the temp sensor just peg out straight to red hot when you start the car or is it a slow climb?

 

Sir Nasty.

It climbs from zero to being pegged in a second or two. so it is not jumping but it climbs fast. I will start a different thread for this since my promary problem still seams to be charging.

TexasHonda. Marked the harmonic balancer. Will track.

Went out fora test drive and my chargelight again will not come on. Even with full load added. Frusterated... Checked the voltage and i am getting 14V+ at idle so i know the alternator is charging. Shorted out the Blue/white wire at the alternator and the light comes on so the bulbstill works.

Replaced the coil for the Tach issue.

So... Still pondering the charge light.
Still pondering the 1V i got on the ELD test
Still pondering the temp sensor.

Leaving the dash in pieces for now till i get other ideas or take it to the shop.

Thank you for the help.