Intermittent Discharge Warning, Filter, and Brake Warning lights on a BJ70- a few solutions (1 Viewer)

[izula]

When you are driving down the road and the Discharge Warning, Filter, and the Brake Warning lights all intermittently light up at the same time (along with a slight buzzing somewhere under the dashboard) on your BJ70, there are a couple of things that could be the source of the problem. A good ‘Mud search will point to a faulty Charge Lamp Relay (CLR) or an issue with the alternator brushes. Here is how you address both of these potential causes (besides slapping your dashboard)…

 

[izula]

The CLR on a 1987 BJ70 from Canada is located under the dashboard behind the glove box. I did not get a photo of the location, but when I take the glove box out again, I’ll snap one and edit this. There are only a few relays up there, so it should not take long to find the correct one.

 

[izula]

Check the relay continuity using an ohm meter or continuity light. If the dash light issues are intermittent, the relay will mostly likely be fine. Cycle the relay operation several times to make sure it works consistently. If the relay works as it should, check the solder joints…

Carefully pry off the top of the relay to expose the innards.

Grab the component board and remove the relay from the plastic housing.

Inspect the solder joints and component board for obvious issues (overheating or bad joints). If the joints are suspect, or if you have the relay open anyway, reflow the solder joints. If the board shows signs of overheating, you can check the diodes or just replace the relay.

After you reflow the solder, confirm continuity and operation, and place the relay back in the plastic housing. Snap the top back on and re-install. If you’ve fixed some obvious issues, go ahead and test drive- maybe the job is done. If you suspect or know that the issue is not fixed, move along to the alternator…

 

[izula]

Pop the hood (or bonnet) and wrestle off the Brush Holder Cover from your alternator. A ‘Mud search will tell you to grab deep 10mm and 8mm sockets (could be wrong on the 8mm) to get the job done (DON'T FORGET TO DISCONNECT YOUR NEGATIVE BATTERY TERMINALS..). This can be done with the alternator on the BJ70, but the power steering pump support and hoses make access a hassle. I did the job without removing the alternator- it just takes some patience. The factory service manual (FSM) shows how to remove the brush holder and separate the IC regulator assembly.

Inspect your brushes per the FSM and replace as necessary:

 

[izula]

The brushes on my BJ70 were the source of the issue- one brush had worn to the point where the wire from the brush to the brush holder had reached its limit.

So I grabbed the brushes that I had picked up from CruiserDan 6 months ago when I first noticed the issue… Word on the street is that Bosch has some brushes that may work too, but I cannot confirm this. The Toyota brushes are cheap- around $3 each if I recall correctly.

 

[izula]

Desolder the old brushes to remove them. The spring tension should shoot the brush and spring from the holder when the solder is sufficiently molten. Be sure to do this where you won’t lose the springs…

Here is a comparison of the old brushes and new brushes. Note the solder on the spring. Be sure to remove this before installing the new brushes so that the springs move freely. There is still some life left to the old brushes. I could have simply removed the shorter one and re-soldered it back with a bit more wire between the holder and the brush. However, I had new brushes on hand, so in they went.

 

[izula]

Installing the new brushes are easy- insert the brush wire through the spring and then into the brush holder. To simplify this, tin the top 1/8 inch of the wire. I did not tin the top of the wire and things worked out smoothly. However, I removed a good bit of solder from the holder and had a big hole to guide the wire through. Ensure that 20mm of brush is exposed and solder the wire.

Repeat for the second brush and ensure that the solder joints are adequate before clipping off the excess wire.

Reattach the IC Regulator then carefully reinstall the assembly into the alternator. Enjoy!

 

[OGBeno]

Nice. Finally some tech. Thank you Rob.

 

[jblueridge]

Super useful! Thanks!

 

[jzilla]

Very well done! Thanks!

 

[locklin]

Great info, thanks!

 

[Dprio34]

Excellent Info and Post, izula. I have had my 1989 LJ70 with a 2.4 2LT motor for a few months now. The Red Light on the Tach and the volmeter blink usually after start for about 5 minutes, and then this goes away for the rest of the day. This week is started blinking after driving 430 miles to Moab. No other lights blink (just red light on tach and voltmeter). Any ideas? Thank you for your time.
Regards,
Don

 

[GAjohnboy]

Installing the new brushes are easy- insert the brush wire through the spring and then into the brush holder. To simplify this, tin the top 1/8 inch of the wire. I did not tin the top of the wire and things worked out smoothly. However, I removed a good bit of solder from the holder and had a big hole to guide the wire through. Ensure that 20mm of brush is exposed and solder the wire.

View attachment 1193547

View attachment 1193548


Repeat for the second brush and ensure that the solder joints are adequate before clipping off the excess wire.

View attachment 1193550


Reattach the IC Regulator then carefully reinstall the assembly into the alternator. Enjoy!

Izula

Desolder the old brushes to remove them. The spring tension should shoot the brush and spring from the holder when the solder is sufficiently molten. Be sure to do this where you won’t lose the springs…

View attachment 1193541


Here is a comparison of the old brushes and new brushes. Note the solder on the spring. Be sure to remove this before installing the new brushes so that the springs move freely. There is still some life left to the old brushes. I could have simply removed the shorter one and re-soldered it back with a bit more wire between the holder and the brush. However, I had new brushes on hand, so in they went.

View attachment 1193544

Izula, great post. My 86 Canadian bj70 24v has the same issue. I have searched for the charge light relay. I'm finding relays behind the glove box, above the right knee by steering column, on left and right panel adjacent to door but I've yet to locate the CLR. Can you help out where you found yours_ Left/ right directly behind glove box? I have searched and searched. Thanks!

 

[izula]

I'll do some digging and get back to you. Its been a few years...

 

[izula]

If I recall correctly, on my LHD BJ70, the CLR is behind the glove box and up under the dashboard. You really should remove the glove box to get a good view in there. I'll be wrenching on the BJ this weekend so I'll try to get a photo of the location and post it up. Good luck.

 

[GAjohnboy]

If I recall correctly, on my LHD BJ70, the CLR is behind the glove box and up under the dashboard. You really should remove the glove box to get a good view in there. I'll be wrenching on the BJ this weekend so I'll try to get a photo of the location and post it up. Good luck.

Thanks, I'll have another look up there. I have the 12v converter for the radio there, maybe i didn't look deep enough. Thanks

 

[GAjohnboy]

If I recall correctly, on my LHD BJ70, the CLR is behind the glove box and up under the dashboard. You really should remove the glove box to get a good view in there. I'll be wrenching on the BJ this weekend so I'll try to get a photo of the location and post it up. Good luck.

If I recall correctly, on my LHD BJ70, the CLR is behind the glove box and up under the dashboard. You really should remove the glove box to get a good view in there. I'll be wrenching on the BJ this weekend so I'll try to get a photo of the location and post it up. Good luck.

Izula, you gave me the confidence to look a third time. I found the relay zip tied to the top of a mass of wires. The CLA turns out to be at least one of my issues as it was melted around the small wires, had obviously overheated. I have replaced my regulator and that fixed the charging issue. Hopefully the CLA fried when the regulator failed. Anyway thanks for the push.

 

[izula]

Right on! Congrats and good luck with the remainder of the work!

 

[tsb621]

Great Info! I'm tracing charge issue on my 87 HJ61 atm. I was not able to find the Charge light relay today, but will check at the back of the glovebox as izula said.

 

[LDowney]

When you are driving down the road and the Discharge Warning, Filter, and the Brake Warning lights all intermittently light up at the same time (along with a slight buzzing somewhere under the dashboard) on your BJ70, there are a couple of things that could be the source of the problem. A good ‘Mud search will point to a faulty Charge Lamp Relay (CLR) or an issue with the alternator brushes. Here is how you address both of these potential causes (besides slapping your dashboard)…

View attachment 1193522

Very helpful and insightful tech in what you have shared here. Thank you

I am currently experiencing this on my Canadian spec (24V) '86 BJ70, but I have just modified my BJ70 by installing a different engine. My original 3B was a total loss so I have replaced it with a 15B-FT. Since the initial start-up of the 15B-FT, these three indicator lights have remained illuminated constantly.

I have confirmed that

A) my charge lamp relay is good (the relay checks out, plus I had a spare relay to use as an independent check)​

B) The 15B-FT alternator is good. Removed it and took it to an alternator rebuild shop. The shop confirmed that it charges (output was 28.1V) and the lamp off signal activates after steady charging is achieved. Also, the shop confirmed that the 15B-FT alternator has much higher capacity. [Max output was beyond 120 amps at 24V which was the equipment limit in the shop]​

Based on your experience, could you project other possible sources for these indicator lights to remain on?

Thanks