1974 R90/6 charging issue (non-stock/non OEM components)

[kjschilling]

1974 R90/6 charging issue/questions, (non-stock charging components)

Recently installed:
• EME Enduralast III alternator kit (rotor, stator, diode board, adjustable voltage regulator, wiring and connectors)
• Westco 12v/30ah AGM battery
• Enduralast starter “cricket” relay
• Enduralast engine wiring harness
• Enduralast battery cable kit (4 gauge)
• Katdash dashboard light upgrade
• 3 ohm dual post coil
All contacts between components and ground points and connections between wiring and posts were cleaned and had a thin layer of NO-OX-ID applied

Issue is charging light remains on (or at least flickering with reduced intensity) even as I increase RPM’s.

As part of my troubleshooting efforts I purchased the CHITECH BMW Electric School Manual from the Chicago Region BMWOA.
In appendix C there is troubleshooting process for testing of the alternator charging circuit;
test 1 (static test w/ignition off); checking for the charge light to be off when ignition is off; my bike passed this test
test 2 (static test w/ignition on, engine not running); checking for charge light to be on when ignition is on; my bike passed this test
test 3 (dynamic test w/system running); part of that test is to check VDC across battery with engine running at 4,000 RPM. Since my bike runs with lights on all the time, voltage should be 13.8 to 14.4,,,,my bike shows 14.4 yet the charging light remains on (flickering with reduced intensity (and occasionally completely out) as compared to when at 1,000-1500 RPM idle the light is on solid and bright).
The fault table C-2 describes the possible cause as “poor connection between the battery and the charge light (most common cause is connector on starter relay)”.
The “how to check” for this condition calls for a cleaning of the starter relay connections and if condition persists to do the following: with ignition on place positive test lead on the “point to be checked” and the negative test lead on the chassis ground. The various “points to be checked” are listed as: positive battery post; positive side of charge light; ignition switch; starter relay and fuse.
I did check and clean the starter relay wiring connectors and applied a light coating of NO-OX-ID to the starter relay posts when first installing the new starter relay

The following is some data I collected while awaiting the above mentioned electrical manual;
12.4 VDC between batt positive and frame ground with ignition on, lights on and engine not running (fully charged battery at 13.5 VDC across terminals, everything off)

run test results
13.7 VDC @ 1500 RPM
14.35 VDC @ 2000 RPM, 2500 RPM, 3000 RPM, 3500 RPM, 4000 RPM and 4500 RPM
13.45 VDC across batt 3 min after run test, everything off
Batt back on charger for 1 hour resulted in 13.5 VDC across batt
At 2500 RPM and above during dynamic run test charge light would flicker and @ 4000 RPM would occasionally (most of the time) go out completely but at 1000 -1500 RPM light would be fully and brightly on


My (neophyte) questions are: is there/are there any specific posts on the ignition switch and the starter relay that I should be testing with the positive lead (as recommended by the CHITECH manual)? And since I have a KATDASH dashboard light upgrade is there a way to test the charge light (as recommended by the CHITECH manual)? Is there any other advice, guidance, insight anyone has to offer as to next steps?

 

[stevenrankin]

Katdash

Looking at the data you have supplied gives me a feeling things are well with your system.

So, if you go to Katdash's web site you will find a note about the flickering charge light. The LED in the Katdash is more sensitive than the clunky bulb and may light dimly or flicker. Please, don't just take my word, Kat has a good section of advice and trouble shooting information on their site.

I have the same problem with my RS along with dimly lit turn signal, brake warning lights dimly lit. I have yet to sort things out as it may only be a crossed ground and nothing to worry about until winter down time.

Good luck and let us know how you make out. St.

 

[kinterridge]

+1 on what Steve said, the Katdash uses a resister instead of the bulb. I think, if memory serves the LED starts flickering where the bulb used to go out when charging and I remember on some bikes it does go out at full charge, when battery is satisfied.

 

[kjschilling]

Looking at the data you have supplied gives me a feeling things are well with your system.

So, if you go to Katdash's web site you will find a note about the flickering charge light. The LED in the Katdash is more sensitive than the clunky bulb and may light dimly or flicker. Please, don't just take my word, Kat has a good section of advice and trouble shooting information on their site.

I have the same problem with my RS along with dimly lit turn signal, brake warning lights dimly lit. I have yet to sort things out as it may only be a crossed ground and nothing to worry about until winter down time.

Good luck and let us know how you make out. St.

Thank you for the response, Steve, much appreciated. It did seem to me as well that the charging function was working so the light flickering was puzzling,,,,I never thought to seek out info from the KATDASH website, thanks for that tip. There are a couple of things I should check; running the dynamic test without my headlight/taillight on as per the recommendation on the KATDASH website and checking the voltage across the various components as recommended in the CHITECH manual. I'll follow up and thanks again!

 

[stevenrankin]

Good show

You look to have things in good hand and should have no problems from here on in. I

It is good to read a posting from someone so well organized and knowledgeable. Enjoy the riding, I forgot to say it is a very good liking bike.

LOL, if you get your flickering light sorted out, how about dropping by and seeing if you can do the same for my RS? Seriously, I will be looking into the situation this winter, after reading Kat's site as well as performing a bunch of tests, I conclude it is a minor thing nothing to get worried about. Still, I am picky and would like to have the lights out. St.

 

[kjschilling]

You look to have things in good hand and should have no problems from here on in. I

It is good to read a posting from someone so well organized and knowledgeable. Enjoy the riding, I forgot to say it is a very good liking bike.

LOL, if you get your flickering light sorted out, how about dropping by and seeing if you can do the same for my RS? Seriously, I will be looking into the situation this winter, after reading Kat's site as well as performing a bunch of tests, I conclude it is a minor thing nothing to get worried about. Still, I am picky and would like to have the lights out. St.

Thank you Steven, so, after running a test as per the KATDASH recommendation, (lights out (I removed the headlight bulb), engine running) there wasn't really much of a difference,,,,,,however,,,I took the bike out for a 25 mile test ride this morning (the first real test ride since getting the bike all put back together again (a major project that started last October)),,,,after about 10 miles of riding at speeds around 45-55 MPH the charging light would be very dim at 1250 RPM and would go out completely at RPMs at 1500 and above,,,so as you noted, there's probably very little to worry about. Before the test ride I checked the battery immediately after removing it from the charger (after spending the night on the charger), the batt checked 13.05 VDC across the battery and 30 minutes later it checked 12.87 VDC across the battery (both checks were performed with everything off). Immediately after the test ride the battery checked 12.9 VDC across the battery with everything off.

So I think I'll leave well enough alone for now,,,next steps; adjust and sync the carbs, and take care of some cosmetic things,,,and maybe upgrade the front braking system to dual rotors,,,,

Thanks agin for your help !