Faulty alternator or charge relay?

[Marty]

G'day, my dash lights (fuel, cooling, brakes) all came on this morning on the way to work as it seems is typical of a charging issue . I am wondering if this is caused by a faulty alternator or charge relay. The volts guage on the dash is showing the alternator to be working fine, a bit over 12 volts and increasing up to 14 as the engine rpm increases. Most people who have this symptom seem to find that the volts are off the guage which has me confused. I don't want to change the alternator to find it's only a relay. Any help appreciated. Cheers, Marty.

[geeves]

Thats a little different to most peoples observation. Most times the volts stick at 12 and the battery goes flat. My money is still on the charge relay though.
if the brushes or diode pack die on the alternator the lights stay on and volts = 12 till battery goes flat.
If the regulator fails it goes high volts until stator winding burns out This brings the lights on but the charge relay is damaged at the same time and will stick causeing the lights to go out but volts at this point = 12 so despite no warning battery still goes flat.

[Marty]

I just put the multimeter across the battery and it's measuring 14v at idle so all seems to be good with the charging. Still can't work out why the lights are on??? Maybe something unrelated? Anyone got a wiring diagram showing the circuit these guages are on?

[BlairNZ]

I appear to be having the same issue with my 3.1 Pighorn - so the charge relay is the blue one located in the fusebox under the bonnet? I have travelled down to my parents place so am away from my shed and parts so I am hoping it is a quick, simple fix so I can get home again without issue!

[geeves]

2 possible relays. Either blue or brown. If its blue borrow one from your other truck It will be the same

[BlairNZ]

Cool, I know there is a blue one under the bonnet, but since I am down in Levin and all my other trucks are in Napier, I am hoping to find a friendly wrecker around the region somewhere who will let me try before I buy... Hahaha All else fails, I will just have to hold on until I get back to Napier because everything else seems to be working except for the A/C!

[BlairNZ]

It was this lil bugger... thanks for the ideas etc, saved a lot of frustration!

[michaelmotes]

I'm having a similar problem. It started yesterday. The day before the battery was dead when I went out to start it that morning. The battery was dated 2003, so I thought that it was just old and replaced it. Everything seemed fine until driving home yesterday. At some point, the volts dropped to 12 while at idle, and the trac, battery, and brake lights came on. Then after giving it some gas, the volts bounced back up to 14, and the lights went out. This happened again at the next red light. Now, the volts won't move from 12, and those dash lights stay on until i rev it to about 2500 rpms. Even at 2500 rmps the volts stay at 12.

Any advice would be much appreciated. It's a 1997 Trooper, US model.

[michaelmotes]

BlairNZ wrote:It was this lil bugger... thanks for the ideas etc, saved a lot of frustration!
What did the blue relay control? I don't have a blue one in mine. Thanks.

[geeves]

is yours a petrol model? whioch engine? They have a different settup