Headlights causing temperature gauge to rapidly rise!

[Rach OB]

I thought I would cut and paste my post from the Introduction section here incase it gets missed.

I have an '06 Navara D22 ZD30 engine. I recently had the heater inlet/outlet water pipe(s) replaced as a result of a pin head sized leak, at the same time the 'second' battery under the bonnet (I have two wired in parallel - don't ask me why, previous owner had this set up) was replaced. Ever since this work my temperature gauge goes up when I turn the head lights on, and when I mean up i mean off the charts ! Above the H line. As soon as I turn the head lights off the temp needle goes back down to just below horizontal. This is exacerbated when I am driving over 80 km/h but around town at 50-60km/h temp gauge stays relatively normal even with the lights on.

I obviously have an electrical gremlim, is there anything I can easily check before paying someone to fault find? Cheers

 

[tweak'e]

any pics of the setup and what was fixed?

 

[Rach OB]

any pics of the setup and what was fixed?

 

[tweak'e]

i would disconnect the temp sensor, which the one at the front top right of the engine. see if problem exists with it disconnected. that may indicate if its engine side related or a dash issue. you will need to find how to reset the engine codes as it will trigger a fault code.

could do with a pic on that right hand side where i assume the 2nd battery is.

i don't like the earth going to the engine from a 2nd battery ie the one connecting to the water hoses. (i assuming they are the pipes replaced.)
the temp gauge is sensitive to voltage change. i would prefer that earth go to the chassis. also check the alternator earth which goes from alternator to radiator support bracket. they alternator would have been removed to replace that metal water pipe.

no mention if you have spot lights fitted.

 

[Rach OB]

i would disconnect the temp sensor, which the one at the front top right of the engine. see if problem exists with it disconnected. that may indicate if its engine side related or a dash issue. you will need to find how to reset the engine codes as it will trigger a fault code.

could do with a pic on that right hand side where i assume the 2nd battery is.

i don't like the earth going to the engine from a 2nd battery ie the one connecting to the water hoses. (i assuming they are the pipes replaced.)
the temp gauge is sensitive to voltage change. i would prefer that earth go to the chassis. also check the alternator earth which goes from alternator to radiator support bracket. they alternator would have been removed to replace that metal water pipe.

no mention if you have spot lights fitted.

Hi mate cheers I will get the extra pic for you shortly.
- will do the temp sensor disconnect and give you an update
- yes that is the earth from the second battery going to the engine block and looking at a previous pic I had prior to the pipe being replaced the earth was connected there as well so it has been replaced in the same spot. Easy fix I will get a longer neg lead and get it onto the chasis.
- will check earth from alternator as well-
- yes i have spots fitted, big boys, on bumper bar right in front of the radiator where they shouldnt be!

 

[Rach OB]

i would disconnect the temp sensor, which the one at the front top right of the engine. see if problem exists with it disconnected. that may indicate if its engine side related or a dash issue. you will need to find how to reset the engine codes as it will trigger a fault code.

could do with a pic on that right hand side where i assume the 2nd battery is.

i don't like the earth going to the engine from a 2nd battery ie the one connecting to the water hoses. (i assuming they are the pipes replaced.)
the temp gauge is sensitive to voltage change. i would prefer that earth go to the chassis. also check the alternator earth which goes from alternator to radiator support bracket. they alternator would have been removed to replace that metal water pipe.

no mention if you have spot lights fitted.

 

[Rach OB]

Tweak'e photos above hope they help. Swapped the earth for the 2nd battery. Can't find the earth for the alternator on the radiator frame not to sure where else to look so attached a pic of that as well for your reference. Cheers

 

[tweak'e]

the alternator ground is there, its actually bolted on next to the rod holding up the bonnet. as long as that hasn't been broken (which doubt).

with parallel batteries i highly recommend you keep both identical and change both of them at the same time. its a common factory setup in the Toyotas and they need to be treated as one big battery.

does the temp gauge problem get worse when the spotlights get turned on?

 

[Rach OB]

ok cheers glad you saw the ground. good info on the batteries. I had the 2nd battery changed probably 8 months ago as well so they have both been swapped out in the past 8 months.

Haven't tried the spotties to see if it makes the temp rise worse (quicker), seems that the standard lights do the job just fine as it only takes about 1 min before the temp gauge goes from just below parallel to just below the H mark when they are turned on. As mentioned if I am just driving around town in 50-80km/h zones i dont have a high temp problem soon as I go over 80 for any sustained period it rises, then if I hit 100km/h it rises very quickly. Incidentally I towed a heavy trailer full of fire wood on the weekend over 300km during the day no problem, drove home in bad weather with lights in and the needle was over the H. You thinking maybe something specific to the low beam? Are they the same wiring harness?

 

[tweak'e]

just a thought here have you checked if it does it with just the park lights on?
i'm wondering if something funky in the dash. and your getting volt leakage into the gauge circuit. a source could be the gauge lights.

with the batteries next time change both and to the same make/model (except left/right versions). with different batteries like you have now, each battery has its own chemistry. slightly different charging/discharging which can reduce the lifespan and sometimes cause weird problems.

 

[Rach OB]

just a thought here have you checked if it does it with just the park lights on?
i'm wondering if something funky in the dash. and your getting volt leakage into the gauge circuit. a source could be the gauge lights.

with the batteries next time change both and to the same make/model (except left/right versions). with different batteries like you have now, each battery has its own chemistry. slightly different charging/discharging which can reduce the lifespan and sometimes cause weird problems.

Hi not sure about the park lights only. I will test both the park lights and spots for you today and let you know. I need to get onto a 100km/h road to do it so just been a bit hard to co ordinate. Roger that with the batteries, cheers

 

[Rach OB]

Hi not sure about the park lights only. I will test both the park lights and spots for you today and let you know. I need to get onto a 100km/h road to do it so just been a bit hard to co ordinate. Roger that with the batteries, cheers

Hi Tweak'e jus a quick update sine last post. I have driven a few times in 80-100kmh zone with lights on (low/high/parkers) and have not had any abnormal temperature rise. Longest drive was for an hour and no issues. So maybe the negative cable on the engine block was a contributing factor a thats all I've changed? Thanks again for your help hopefully we have it sorted.