11.3V at headlight pins but not lighting up
#1
11.3V at headlight pins but not lighting up
So, Ive pretty done everything I can think of at this point to determine why my headlights will not come on. I removed the plug on the back of headlight(both) and checked the voltage at pins. Shows 11.3V. The bulb is good because it works with direct 12V from battery.
Then I removed the TIPM to get to the front end module. I jumpered pin 9 with hot for bulb, and connected other light bulb terminal directly to ground and bulb lights up again.
I'd be thankful for any suggestions. I'm sure I can fix it(outside of module replacement) but definitely want to exhaust options before taking to dealer
Confused I have 12V at bulb which suggest circuit is complete but still no light.
2009 Dodge Ram 1500 Hemi
Then I removed the TIPM to get to the front end module. I jumpered pin 9 with hot for bulb, and connected other light bulb terminal directly to ground and bulb lights up again.
I'd be thankful for any suggestions. I'm sure I can fix it(outside of module replacement) but definitely want to exhaust options before taking to dealer
Confused I have 12V at bulb which suggest circuit is complete but still no light.
2009 Dodge Ram 1500 Hemi
#3
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Do you have access to the wiring diagram? I assume you do as you are able to measure voltages. The headlamp bulbs are wired directly to the TIPM by 3 wires each, one supply for the High Beams, one supply for the low beams and the ground. Are you sure you are measuring the 11.3 VDC to the ground or maybe you are measuring between the High and Low beam signals.
#4
#5
pins tested
The location I tested was headlight plug adapter in the back of plug. Per the writing diagram one is hot and other blk/blue is ground. Putting a meter across these two pins its 11v. Someone at dodge said they believe its ground controlled. It could be a bad ground, but looks grounded if I have 11v.
From what to what should I check continuity? And would I still get 11v if module was bad?
From what to what should I check continuity? And would I still get 11v if module was bad?
#6
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If you want to know if the TIPM is working, take an ohmeter and measure from pin 2 (RTN) of the connector at the bulb to the battery ground. This should be open when the lights are off. When the lights are commanded on, the TIPM will provide a ground (I'm assuming the switched ground is via a relay, at this time, you will see a short to ground. If you don't, either the TIPM is bad or the relay on the TIPM is bad.
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#8
The location I tested was headlight plug adapter in the back of plug. Per the writing diagram one is hot and other blk/blue is ground. Putting a meter across these two pins its 11v. Someone at dodge said they believe its ground controlled. It could be a bad ground, but looks grounded if I have 11v.
From what to what should I check continuity? And would I still get 11v if module was bad?
From what to what should I check continuity? And would I still get 11v if module was bad?
It is ground controlled. Just do a check with headlights off and you'll see. Put your meter from ground to battery and there won't be anything until you turn the headlights on. There's always going to be voltage on the + side of the connector.
Also, I believe the spec is 5ohm's for the headlight circuit both High and low beam. If it's higher than 5ohm then there is a short to ground, if the resistance is lower than 5ohm, then the tipm will need to be replaced. To test this, one end of meter is at bottom side of tipm plug and other is at headlamp connnector. C7 I believe is the correct connector. Headlight wiring should be the same at connector as it is at the plug. Mine is white/blue and white/green stripe. Yours maybe different since its an '09.
I'm just surprised that there are no DTC codes??? Have you checked? I'm not talking about a check engine light, speaking of "hidden" DTC codes that need to be pulled by a Dodge Specific code reader such as a handheld tuner or higher dollar scantool.
Last edited by dirtydog; 10-04-2012 at 01:51 PM. Reason: added wiring clarification
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The TIPM connector on the '09 is C4. The pin assignments are as follows on C4.
Left Headlight
C4-pin2 = High Beam voltage
C4-pin9 = Low Beam voltage
C4-pin1 = Return (basically ground when switched on)
Right Headlight
C4-pin7 = High Beam voltage
C4-pin16 = Low Beam voltage
C4-pin8 = Return (basically ground when switched on)
Left Headlight
C4-pin2 = High Beam voltage
C4-pin9 = Low Beam voltage
C4-pin1 = Return (basically ground when switched on)
Right Headlight
C4-pin7 = High Beam voltage
C4-pin16 = Low Beam voltage
C4-pin8 = Return (basically ground when switched on)
#10
That is not how electricity works, you can't "pass voltage". The bulb will only light up with current flowing through the filament and for current to flow, you need a return (RTN) to ground.
If you want to know if the TIPM is working, take an ohmeter and measure from pin 2 (RTN) of the connector at the bulb to the battery ground. This should be open when the lights are off. When the lights are commanded on, the TIPM will provide a ground (I'm assuming the switched ground is via a relay, at this time, you will see a short to ground. If you don't, either the TIPM is bad or the relay on the TIPM is bad.
If you want to know if the TIPM is working, take an ohmeter and measure from pin 2 (RTN) of the connector at the bulb to the battery ground. This should be open when the lights are off. When the lights are commanded on, the TIPM will provide a ground (I'm assuming the switched ground is via a relay, at this time, you will see a short to ground. If you don't, either the TIPM is bad or the relay on the TIPM is bad.