Electrical problem
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Senior User
Joined: Mar 2005
Posts: 101
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From: Jamestown, NY
Electrical problem
Long time since I had a problem that I couldn't find answer here. At low rpms and idle the headlights flicker, the turn signals blink fast and the back up sensors go off. When braking the backup sensors go off at low rpms. New battery and alternator last summer. Thoughts?
Fleet Mechanic
Joined: Feb 2011
Posts: 1,812
Likes: 88
From: Thousand Oaks, CA
What does the battery voltage look like?
A digital voltmeter that plugs into the cigarette lighter will give you more info than the dash voltmeter gauge.
At idle the alternator output is barely keeping up with demand especially with the headlights on.
The voltage should be around 13.8-14.0v.
If the voltage is down around 12.6v at idle you're running on the battery.
There may be poor battery/alternator connections, poor ground connections or the alternator regulator is weak.
Veteran/Sheepdog
Joined: Feb 2012
Posts: 6,047
Likes: 110
From: Western AR
That is the starter solenoid. Those two double gray 12 gauge fusible link wires are your fusible links FROM the alternator B+ and TO the main fuse box over by the brake booster. You will need new links (you have to make them nowadays), or you can replace them with in-line fuses. Car stereo shops are good sources for the fuses. The B+ wire should be 4 gauge black and orange, and the wire to the fuse box should be the same (maybe 6 gauge, but still black/ong).
Go here for fusible links:
You really need to thoroughly inspect the rest of your charging system for more corrosion (battery harness (red) and the grounds to your engine and frame (black).
Go here for fusible links:
You really need to thoroughly inspect the rest of your charging system for more corrosion (battery harness (red) and the grounds to your engine and frame (black).
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
In addition to Mike's advice:
You should be able it simply install new ring terminals IF the corrosion hasn't advanced too far inside the insulation of the fuse links for the wire to reach the terminal post-repair. You'll have to strip some insulation and see how far the rot advanced.
I'd also install a new starter relay as cleaning up that one is likely to last about one winter before it corrodes again.
You should be able it simply install new ring terminals IF the corrosion hasn't advanced too far inside the insulation of the fuse links for the wire to reach the terminal post-repair. You'll have to strip some insulation and see how far the rot advanced.
I'd also install a new starter relay as cleaning up that one is likely to last about one winter before it corrodes again.
Thread Starter
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Senior User
Joined: Mar 2005
Posts: 101
Likes: 0
From: Jamestown, NY
Check the connections on the alternator, too.
What does the battery voltage look like?
A digital voltmeter that plugs into the cigarette lighter will give you more info than the dash voltmeter gauge.
At idle the alternator output is barely keeping up with demand especially with the headlights on.
The voltage should be around 13.8-14.0v.
If the voltage is down around 12.6v at idle you're running on the battery.
There may be poor battery/alternator connections, poor ground connections or the alternator regulator is weak.
What does the battery voltage look like?
A digital voltmeter that plugs into the cigarette lighter will give you more info than the dash voltmeter gauge.
At idle the alternator output is barely keeping up with demand especially with the headlights on.
The voltage should be around 13.8-14.0v.
If the voltage is down around 12.6v at idle you're running on the battery.
There may be poor battery/alternator connections, poor ground connections or the alternator regulator is weak.
In addition to Mike's advice:
You should be able it simply install new ring terminals IF the corrosion hasn't advanced too far inside the insulation of the fuse links for the wire to reach the terminal post-repair. You'll have to strip some insulation and see how far the rot advanced.
I'd also install a new starter relay as cleaning up that one is likely to last about one winter before it corrodes again.
You should be able it simply install new ring terminals IF the corrosion hasn't advanced too far inside the insulation of the fuse links for the wire to reach the terminal post-repair. You'll have to strip some insulation and see how far the rot advanced.
I'd also install a new starter relay as cleaning up that one is likely to last about one winter before it corrodes again.
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Veteran/Sheepdog
Joined: Feb 2012
Posts: 6,047
Likes: 110
From: Western AR
That heat shrink on the fusible links was never intended to come off. I dissected mine when one leg got burnt, and it was VERY tough to get off. The adhesive they use in the heat shrink is like super, super glue. Don't forget your grounds. They are just as (if not more) important as that positive cable.
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Fleet Owner
Joined: Apr 2008
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From: 0,0,1
Go to a Home Depot or an electrical supply house and get one of these that will take the two wires. You can drill the mounting hole larger to fit the stud if need be. I used one of these to fix the end of the harness that bolts down at the starter. It cost me 50-cents and I didn't have to replace the whole harness. Wrap it in electrical tape when you're done.
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Senior User
Joined: Mar 2005
Posts: 101
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From: Jamestown, NY
The voltage at idle at the battery terminal is 14.85. Good? Where else can I check it from?
It seems to be a low voltage problem. The rear sensors sound off when I depress the brake unless the engine is revving. The turn signals are also going fast or not working at all when at idle or breaking to make a turn, low speed.
I'm guessing the alternator or voltage regulator (does it have one)? How do you test these?
thanks!
Fleet Mechanic
Joined: Feb 2011
Posts: 1,812
Likes: 88
From: Thousand Oaks, CA
With nothing on the battery voltage across its terminals should be around 12.4-12.8v.
Normal at idle or when running it should be around 13.2-13.5v.
When recharging after starting the voltage may jump up to 14.2-14.5v.
I think the voltage regulator is built into the alternator.
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