Dash lights flickering

[scuba steve]

Hey mudders;
On my hdt the dash lights flicker on occasionally like the alternator is crapped out, then as quickly as they go on, they are back off.
Of the few times it's happened, it's after a bumpy dirt road.
Any ideas?

 

[kim]

Ground is the first thing that comes to mind every time I hear of an intermittent electrical issue. 2nd is connections at battery terminals.

 

[meafordmike]

connection at back of Alternator. ensure its good a tight.

 

[bj40green]

Hey mudders;
On my hdt the dash lights flicker on occasionally like the alternator is crapped out, then as quickly as they go on, they are back off.
Of the few times it's happened, it's after a bumpy dirt road.
Any ideas?

Only the dash lights ?

 

[scuba steve]

Well actually the only lights I noticed that came on are the timing belt and the over boost red light.
Still think it could be the alternator plug?

 

[bj40green]

What truck are we taling about? 40, 80?

Rudi

 

[scuba steve]

80 diesel; 1hdt

 

[finderscuba]

Alternator for sure. Likely the plug on the back of the alternator is loose. Pull it, pinch the terminals, add some dielectric grease and plug it back in.

Also, check your bottom alternator mounting bolt for tightness. I recently found mine was sheared which could cause intermittent ground issues.

You should get your alternator load tested as well to check for possible problems.

 

[scuba steve]

Thanks for the replies everyone; I will look at all those and see what is up,

 

[IanB]

So did you ever figure out the cause of your issues? I've got the same symptoms today coming home from my parents. Noticed the overboost light flickering, then the timing belt and other lights in the bottom left of the dash, then noticed the alternator light flickering as well. Shut off the havoc and most electrical systems I could and it got better, but it has me concerned.

Earlier on the trip it froze up after sitting outside for 3 days in the bitter cold, I'm thinking the fuel gelled, tried to boost it but couldn't get it to stay running, 20 min in the heated shop got me back up and running.

 

[Douglas S]

The alternator plug is notorious for this.

 

[finderscuba]

So did you ever figure out the cause of your issues? I've got the same symptoms today coming home from my parents. Noticed the overboost light flickering, then the timing belt and other lights in the bottom left of the dash, then noticed the alternator light flickering as well. Shut off the havoc and most electrical systems I could and it got better, but it has me concerned.

Earlier on the trip it froze up after sitting outside for 3 days in the bitter cold, I'm thinking the fuel gelled, tried to boost it but couldn't get it to stay running, 20 min in the heated shop got me back up and running.

Without a doubt it is either a loose connector on the back of the alternator, or your alternator itself. Start with the simple things.

Cold start: air in your fuel lines? lost fuel prime? Bad glow plugs? Try priming your fuel filter before trying to start. Pedal to the floor until it fires. You did replace all those fuel lines and clamps, right? Also check the o-ring on the bottom of the fuel/water separator.
I could be free to help. PM me of you need help.

 

[IanB]

OK, home now and had a chance to poke around under the hood. Alternator plugs are tight, found one battery neg cable loose so I tightened that up. Pulled the cover off the power distribution block and everything was tight under there, and followed all the ground cables and tightened them as well.

Took it for a test drive, turned on every accessory I could and no flickering lights, so here's hoping it was just a loose batter cable!

As for the cold start issue a few days prior, the fuel primer was frozen so I couldn't depress it when it was outside, after pulling it into the shop it had freed up again. I have no reason to believe there was any air in the lines, I think it was simply gelled fuel in the lines/filter. I've had no other issues prior to this, and no problems since related to fuel.

 

[Douglas S]

Are you using anti-gel in your fuel?

 

[bvissers]

I have had same issue with my HDJ, it was the ground at the alternator, those contact points that bolt down the alaternator need to bee clean and tight

 

[IanB]

Are you using anti-gel in your fuel?

I've been using Power Service diesel supplement in the white jug, about 250ml per tank of fuel. When the truck died I put another dose in with the 1/2 tank of fuel left in the truck, and teamed with 20min in the heated shop it was enough to get me up and running again. Perhaps I need to up the dose when I'm going to be expecting more of the truck?

I drove it again last night and no more signs of flickering!

 

[IanB]

I may not be totally out of the woods yet, I tightened all battery clamps and took the truck out of town for New Years, saw some flickering of the overboost light a few times, none of the other dash lights this time, no alternator light, just the overboost light, and not as frequently as before. Mostly when under heavy load like a passing situation and that kind of thing. Any other ideas?

 

[finderscuba]

Ian,

I'm still betting on the alternator. Pull the plug on the back, squeeze the female terminals, spray in some contact cleaner, dielectric grease, then button up. Also tighten your bottom alternator pivot bolt. If that fails, you might need a rebuild (brushes). I've been through this in the past.

 

[IanB]

Ian,

I'm still betting on the alternator. Pull the plug on the back, squeeze the female terminals, spray in some contact cleaner, dielectric grease, then button up. Also tighten your bottom alternator pivot bolt. If that fails, you might need a rebuild (brushes). I've been through this in the past.

Ya, I'll have to take a closer look at that this week, thanks!

 

[canucksafari]

Ian,

I'm still betting on the alternator. Pull the plug on the back, squeeze the female terminals, spray in some contact cleaner, dielectric grease, then button up. Also tighten your bottom alternator pivot bolt. If that fails, you might need a rebuild (brushes). I've been through this in the past.

Had a similar problem with the wife's Safari this summer... that plus only registering 24Vs on the voltage meter. Even switched in the alternator and batteries from my 5 spd to eliminate the alternator and the batteries as the cause. I could have saved myself a lot of time and effort if I first checked the batteries' ground wires and the engine ground. All three were suffering from surface corrosion. Everything got smeared in dielectric grease as it went back together. Problem was solved.

Afterthought - also make sure the alternator belt is properly tensioned. You'd likely hear it if it wasn't.