Volt meter drops 90 flhtcu
#21
07-18-2009 | 12:41 PM
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Joined: Dec 2005
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From: NC USA
#22
07-18-2009 | 11:49 PM
Road Captain
Joined: Jun 2008
Posts: 640
Likes: 13
From: Hickory, NC area
Hess, Squeal and T150 - y'all are just scaring people now!
Plus, I think I was the one that actually hijacked the thread in my own self-indulgence. It is, however, the same problem identified by the OP. Once I have a weekend to get in there, I promise to post the hijackers solution. My wife is taking the kids to see her family in about 10 days, so I might actually have some riding time and tinkering time.
Now, where did I put that old leather tool pouch.....
Plus, I think I was the one that actually hijacked the thread in my own self-indulgence. It is, however, the same problem identified by the OP. Once I have a weekend to get in there, I promise to post the hijackers solution. My wife is taking the kids to see her family in about 10 days, so I might actually have some riding time and tinkering time.
Now, where did I put that old leather tool pouch.....
#23
08-05-2009 | 08:59 AM
Road Captain
Joined: Jun 2008
Posts: 640
Likes: 13
From: Hickory, NC area
Just as a follow-up, I did have the chance to pull it apart this weekend and tinker. I cleaned all the terminals on the relays and put a little dab of dielectric grease on there when I tightened them back down. The grounds that attach to the terminal block connected to the upper fork area had a few loose ones and in cleaning and what not several of the ends actually broke. So I replaced 3 or 4 of the 6 (I think it was 6). Put it all back together and now my meter still swings wildly, but my turn signals work about 80% of the time.
I didn't try the jump wire across the ignition relay as I was a little unsure and didn't want to blow anything. I suspect I need a new switch and as I have said I will probably get one so I can get rid of the current look anyway.
I didn't try the jump wire across the ignition relay as I was a little unsure and didn't want to blow anything. I suspect I need a new switch and as I have said I will probably get one so I can get rid of the current look anyway.
#24
05-02-2010 | 11:53 PM
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Joined: Aug 2007
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The row of breakers, I assume are arranged the same on most FLs, but an easy check is with a test light or meter. You must have the switch in ACC only position to find it for certain.
You will have one that is always "hot" for the clock and radio memory. The ACC breaker supplies the brakes lights, turn signals, power to the start button, "line" power to the starter relay, horn, radio, oil/neutral lights and dash lights. That's why there is a drastic voltage drop when brakes are applied. And of course one breaker each, for the ignition and lights - which may be jumped together (from the factory)
A switch that's been tampered with, as in a repo operation is not the cause of failure, simply the contacts in the switch itself are wimpy and get tired after a long time. Those style switchs are obsolete/unavaliable and unservicable (can't take them apart like most HD switches)
When you find the ACC breaker, run a temporary wire from the battery to either side of the breaker and you'll see the volt gauge stay "up" when any of the functions are applied.
Assuming the switch checks out to be weak, it's really easy to add a relay under the seat to supply power to the ACC breaker by using the lead from the switch to trigger the relay. I don't have photos of mine, but if anyone needs more info on that modification let me know.
Mjunk1 - replace your turn signal flasher while you're messing with it too. Remember there are 2 and one runs the 4-ways, it's likely OK.
I had a similar problem for years and was replacing the wrong one cause I didn't know there were 2 - DUH...
You will have one that is always "hot" for the clock and radio memory. The ACC breaker supplies the brakes lights, turn signals, power to the start button, "line" power to the starter relay, horn, radio, oil/neutral lights and dash lights. That's why there is a drastic voltage drop when brakes are applied. And of course one breaker each, for the ignition and lights - which may be jumped together (from the factory)
A switch that's been tampered with, as in a repo operation is not the cause of failure, simply the contacts in the switch itself are wimpy and get tired after a long time. Those style switchs are obsolete/unavaliable and unservicable (can't take them apart like most HD switches)
When you find the ACC breaker, run a temporary wire from the battery to either side of the breaker and you'll see the volt gauge stay "up" when any of the functions are applied.
Assuming the switch checks out to be weak, it's really easy to add a relay under the seat to supply power to the ACC breaker by using the lead from the switch to trigger the relay. I don't have photos of mine, but if anyone needs more info on that modification let me know.
Mjunk1 - replace your turn signal flasher while you're messing with it too. Remember there are 2 and one runs the 4-ways, it's likely OK.
I had a similar problem for years and was replacing the wrong one cause I didn't know there were 2 - DUH...
#25
05-03-2010 | 07:48 AM
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Joined: Apr 2007
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From:
T150VEJ, Dr. Hess and SQDealGeorge,
I for one appreciate all the valuable input that you guys give to the forum. i too have a 90 flhtcu with the same problem. had it for yrs, keep saying I am going to fix it. just havent got to it yet. but now i know where to start. I really dont post too much as the SEARCH function works real good for frequently asked questions. i know you guys get tired of answering the same questions over and over. Anyway, thanks for being here for us dummies that think we are wrenches !
later...............
I for one appreciate all the valuable input that you guys give to the forum. i too have a 90 flhtcu with the same problem. had it for yrs, keep saying I am going to fix it. just havent got to it yet. but now i know where to start. I really dont post too much as the SEARCH function works real good for frequently asked questions. i know you guys get tired of answering the same questions over and over. Anyway, thanks for being here for us dummies that think we are wrenches !
later...............
#26
05-03-2010 | 10:34 AM
HDF Community Team
Joined: Dec 2005
Posts: 4,642
Likes: 1,884
From: NC USA
One thing that's hard to grasp is that the acc voltage runs from the main switch thru the starter relay and though it may start OK, the relay can be weak on the normally closed contacts. The acc side of the relay may be good and the start side be weak. Then there's a number of connections throughout the harness, any of which can cause a problem.
I wired mine differently than DrHess and was looking to take care of a somewhat related, but different problem. If the bouncing voltmeter is the only issue, you can simply remove the power lead from it and install another (separate) lead from the voltmeter to the ignition or acc breaker and help it a lot. Alternatively, you could use the arrangement I'm running if turn signals are acting up, or if it's the "dreaded click" issue many seem to experience, you could use DrHess' arrangement. But you could also "bullet proof" it all by intergrating both methods.
Thanks for the roses Paco. I have to thank everyone who ever posted anything here. I've learned a LOT myself, if not by specific info given, by questions asked which have often lead me to seek the answer, even if it did not apply to anything I owned. It's a really great forum, Evo section particularly
#28
05-03-2010 | 09:09 PM
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Joined: Aug 2007
Posts: 8,123
Likes: 2,943
From: NW AR
Yeah, Paco, like the phone company, I'm here to help. Actually, teh intraw3bz, y0, have increased the efficiency of our society tremendously. For good and bad, it seems, as the bankers are now more efficiently screwing us to the wall. Anyway, at least we can share how-to's for things that we've been there on. It's the same with my cars on their specific forums. I've been riding Harley's since 1979. Way before I became a doctor. I guess I did it backwards there.
Anyway, JG, I wrote a rough tutorial/guide and posted it here somewhere on how to add an extra relay. Here it is again:
How I Added The Extra Relay.
First off, buy a relay at the auto parts store. I used one that is the same as the regular start relay, located under my right side cover, bolted to the oil tank. You can get the part number off the old relay and have them cross it. It's a common relay and not expensive. Two types are available, one that has a screw mount like the original and one without. Get the screw mount one. Relay sockets are available as well, or you can use wire flag type connectors and push them on the relay terminals directly. Pull the seat off. Mount the relay to the inside of the left panel using a screw that holds the rear brake MC reservoir on. Run a heavy gauge wire from the starter solenoid post that goes to the battery, like 12ga. Put a fuse in the line, like 20 amp or so. You can get a inline fuse holder for the newer automotive flag fuses at radio shack. Connect the other end from the fuse to a normally open post of the relay. Connect the opposite post (the one that connects to the normally open one when the relay is energized) to a heavy wire running down to the small wire post on the starter solenoid. Leave the original small wire there too. Now you only have to energize the new relay. Run a wire (can be smaller, like 16 ga smaller if you wanted) from the starter relay coil to the coil of the new relay. You can run both sides, or one side and ground the other, whatever you want. This way, when the starter relay is energized by the rest of the bike (push button, etc.), both relays engage in parallel and both relays put +12V on the solenoid coil. The new relay puts a full +12V without any of the dozen electrical connections and little bits of wire in the way. It is fused so that if something bad happens, the fuse blows and not the battery (or wire, more likely). When you're testing it, have the battery cables somewhat loose on the battery so you can pull them and stop the whole system should you have screwed up the wiring somewhere.
Anyway, JG, I wrote a rough tutorial/guide and posted it here somewhere on how to add an extra relay. Here it is again:
How I Added The Extra Relay.
First off, buy a relay at the auto parts store. I used one that is the same as the regular start relay, located under my right side cover, bolted to the oil tank. You can get the part number off the old relay and have them cross it. It's a common relay and not expensive. Two types are available, one that has a screw mount like the original and one without. Get the screw mount one. Relay sockets are available as well, or you can use wire flag type connectors and push them on the relay terminals directly. Pull the seat off. Mount the relay to the inside of the left panel using a screw that holds the rear brake MC reservoir on. Run a heavy gauge wire from the starter solenoid post that goes to the battery, like 12ga. Put a fuse in the line, like 20 amp or so. You can get a inline fuse holder for the newer automotive flag fuses at radio shack. Connect the other end from the fuse to a normally open post of the relay. Connect the opposite post (the one that connects to the normally open one when the relay is energized) to a heavy wire running down to the small wire post on the starter solenoid. Leave the original small wire there too. Now you only have to energize the new relay. Run a wire (can be smaller, like 16 ga smaller if you wanted) from the starter relay coil to the coil of the new relay. You can run both sides, or one side and ground the other, whatever you want. This way, when the starter relay is energized by the rest of the bike (push button, etc.), both relays engage in parallel and both relays put +12V on the solenoid coil. The new relay puts a full +12V without any of the dozen electrical connections and little bits of wire in the way. It is fused so that if something bad happens, the fuse blows and not the battery (or wire, more likely). When you're testing it, have the battery cables somewhat loose on the battery so you can pull them and stop the whole system should you have screwed up the wiring somewhere.
#29
05-04-2010 | 08:02 AM
Road Master
Joined: Aug 2007
Posts: 848
Likes: 8
From:
Yeah, Paco, like the phone company, I'm here to help. Actually, teh intraw3bz, y0, have increased the efficiency of our society tremendously. For good and bad, it seems, as the bankers are now more efficiently screwing us to the wall. Anyway, at least we can share how-to's for things that we've been there on. It's the same with my cars on their specific forums. I've been riding Harley's since 1979. Way before I became a doctor. I guess I did it backwards there.
Anyway, JG, I wrote a rough tutorial/guide and posted it here somewhere on how to add an extra relay. Here it is again:
How I Added The Extra Relay.
First off, buy a relay at the auto parts store. I used one that is the same as the regular start relay, located under my right side cover, bolted to the oil tank. You can get the part number off the old relay and have them cross it. It's a common relay and not expensive. Two types are available, one that has a screw mount like the original and one without. Get the screw mount one. Relay sockets are available as well, or you can use wire flag type connectors and push them on the relay terminals directly. Pull the seat off. Mount the relay to the inside of the left panel using a screw that holds the rear brake MC reservoir on. Run a heavy gauge wire from the starter solenoid post that goes to the battery, like 12ga. Put a fuse in the line, like 20 amp or so. You can get a inline fuse holder for the newer automotive flag fuses at radio shack. Connect the other end from the fuse to a normally open post of the relay. Connect the opposite post (the one that connects to the normally open one when the relay is energized) to a heavy wire running down to the small wire post on the starter solenoid. Leave the original small wire there too. Now you only have to energize the new relay. Run a wire (can be smaller, like 16 ga smaller if you wanted) from the starter relay coil to the coil of the new relay. You can run both sides, or one side and ground the other, whatever you want. This way, when the starter relay is energized by the rest of the bike (push button, etc.), both relays engage in parallel and both relays put +12V on the solenoid coil. The new relay puts a full +12V without any of the dozen electrical connections and little bits of wire in the way. It is fused so that if something bad happens, the fuse blows and not the battery (or wire, more likely). When you're testing it, have the battery cables somewhat loose on the battery so you can pull them and stop the whole system should you have screwed up the wiring somewhere.
Anyway, JG, I wrote a rough tutorial/guide and posted it here somewhere on how to add an extra relay. Here it is again:
How I Added The Extra Relay.
First off, buy a relay at the auto parts store. I used one that is the same as the regular start relay, located under my right side cover, bolted to the oil tank. You can get the part number off the old relay and have them cross it. It's a common relay and not expensive. Two types are available, one that has a screw mount like the original and one without. Get the screw mount one. Relay sockets are available as well, or you can use wire flag type connectors and push them on the relay terminals directly. Pull the seat off. Mount the relay to the inside of the left panel using a screw that holds the rear brake MC reservoir on. Run a heavy gauge wire from the starter solenoid post that goes to the battery, like 12ga. Put a fuse in the line, like 20 amp or so. You can get a inline fuse holder for the newer automotive flag fuses at radio shack. Connect the other end from the fuse to a normally open post of the relay. Connect the opposite post (the one that connects to the normally open one when the relay is energized) to a heavy wire running down to the small wire post on the starter solenoid. Leave the original small wire there too. Now you only have to energize the new relay. Run a wire (can be smaller, like 16 ga smaller if you wanted) from the starter relay coil to the coil of the new relay. You can run both sides, or one side and ground the other, whatever you want. This way, when the starter relay is energized by the rest of the bike (push button, etc.), both relays engage in parallel and both relays put +12V on the solenoid coil. The new relay puts a full +12V without any of the dozen electrical connections and little bits of wire in the way. It is fused so that if something bad happens, the fuse blows and not the battery (or wire, more likely). When you're testing it, have the battery cables somewhat loose on the battery so you can pull them and stop the whole system should you have screwed up the wiring somewhere.
Thanks for the tutorial. What exactly does this relay do? Sounds like it provides more power to the starter solenoid. I don't have any problems with starting. I have problems with my voltmeter jumping all over the place. Thanks!
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Bill McKibbon (05-06-2019)
#30
05-04-2010 | 08:04 AM
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they were a helluva beer enhancer though !
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Bill McKibbon (05-06-2019)