Some history: about a year ago my distributor quit on me and I had a reconditioned one installed to keep costs low. About 6 months ago the Tach was acting up giving me false readings. I pulled the connector @ the distributor apart and put conductive grease into it which seemed to fix the problem. Since that time my idle rpms read 900 when normally it’s 500(when it idles at 500 the steering wheel shakes slightly which it’s not doing now).

The problem: A week ago I started my 91 Accord EX in the cold and the battery light stayed on after starting which has never happened before. I also noticed the dash lights were dim, the power windows were slower and the voltage reading on my aftermarket stereo displayed 11.1V which told me the alternator had no output. While trying to make it to my work on just battery power, I was sitting at a stop light when my rpms dropped from ~900 to ~500. The drop in rpms was similar to when I turn on my A/C, after the drop, my stereo voltage was 14.3V, dash lights and windows were normal. It happened again another cold morning (batt light was on & low voltage), this time I popped the hood and wiggled the power cable on the alternator along with the 4 conductor connector, nothing seemed to change until I tapped the alternator housing with my flash light. Doing that seemed to "turn it on." The Honda dealer said it's more than likely the brushes in the alternator because of me tapping it to get it to work, which I can understand. But what's got me wondering is why would it just "turn on?” If the brushes are starting to fail wouldn’t I see erratic voltage readings? Does the alternator have internal circuitry that disables the output if there is no internal AC being generated? Is there a relay inside the alternator/voltage regulator? The Honda dealer said, under certain conditions, the ECU can turn off the alternator. It’s been almost 2 weeks since I’ve tapped the alternator and it’s consistently putting out 14.3V and the idle rpms seem to be dropping down to the normal 500. Although, lately I’ve noticed while idling @ a stop light, the dash lights dim a bit when the turn signal is lit, so the dash lights pulse inversely with the turn signal. I’m wondering if the alternator/voltage regulator is about to die or the ELD is getting false readings(because of the rpms) or the wiring is about to fail?

 

It may just be your alternator. You can try replacing the alternator brush assembly. Refer to this thread, I believe your 91 Accord should use the same part, 31105-PR7-01, as the 5th gen Accord.

https://www.hondaaccordforum.com/for...ad.php?t=37116

 

Honda Dealership wanted $550 for a new alt. or $300 for brushes. Local parts stores want $321 for a new aftermarket alt. or $261 for a refurbished one. I ordered mine online for $75 on ebay from auto_electric_outlet and paid $30 to ship to Canada. Had it installed with 2 new fan belts now the car idles lower, shifts at lower rpms and most importantly 14.3 volts @ idle. Thanks for the info.

 

The Honda dealership quoted you wrong. The list price is $28.87 for the brush assembly, Honda part number 31105-PR7-A01. Your Accord uses the same brush assembly as shown in the link I posted above.

This is Majestic Honda's link for you to see the list price and discounted price, theirs is even lower as internet pricing is usually discounted.

hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=ACCORD&catcgr y2=1992&catcgry3=4DR+EX&catcgry4=KA4AT&catcgry5=AL TERNATOR+%28DENSO%29

I actually still have that part and I only paid twenty something dollars.

 

Going to attempt this brush replacement for a 1991 accord. Part was $35 from the dealer. Hoping to not have to remove the alternator . We'll see how it goes.