Isuzu Trooper Owners Club UK™

[Twister]

I know there have been several threads on here regarding Alternators / Blue charge relays and the vagueness of the voltmeter / oil pressure guage, but I had something very strange happen to my 3.0DT 2 days before Xmas, so I thought I'd share it and see what anyone else thinks.

I've had the car over two years now, and ever since I bought it it has had what I beleived to be very lazy oil pressure pick up from cold starts. Sometimes taking up to 10 seconds from firing up to registering any oil pressure. This to the point that I have in the past had the sump off to check the pick up pipes, as well as checking the oil pressure relief valves.

Anyway, gets in the car on the Friday morning to go to town for some last minute shopping. Same as any other cold start. Leaves the car in a car park in town for 2 hours, and when I come back to start it it fires up and the Alternator warning light, along with the 4wd light stay on. Also the heater blower fan isn't working. Switched it off, tried again, same thing.
So I did the obvious, Checked the belts,checked all earth points, took the blue relay out and cleaned the contacts, checked the battery posts and the alternator posts and sprayed some WD40 into the alternator. Nothing. It stayed this way all day, with signs that the batteries were getting no charge ( lights getting dimmer etc..).

The next day when I started it in the morning it cranked over slowly, fired, and everything was back to normal. The strange thing was the oil pressure registered almost instantly, and has done ever since. Now however, I'm reading 14.4v across the battery terminals with the engine running, which is good, but with all the accessories switched on I'm only getting 11.8v. I'm thinking worn brushes or commutator in the alternator, or possibly a dodgy regulator, but why the improvement in the oil pressure readings, ? thats the thing that's baffled me. I know the oil pressure guage/meter are electronic, but . Could this be down to a dodgy blue relay?

I know from previous posts that there are other people out there who have 3.0DT's that take a long time to register oil pressure from a cold start, and it now appears to me that it is some sort of electrical problem, which is far better than an internal oil problem .

Any input would be very much appreciated before I condemn the alternator.
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"Tongue-tied and Twisted; just an Earth-bound misfit,  I..."  -  PF

LTM # 000002

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[eithan h]

check with a half decent dealer but i think when they first came out there was an issue with the alternator giving all the symptoms you describe. i think you had to check the blue and white wire on the back of the alternator and in some cases replace the alternator and the section of loom that plugs in just under the battery.