Turn signal indicator lamp socket connection failure

[Seabee]

Hi guys,

I've been having trouble keeping a good connection between the indicator lamp socket and the circuitry on the back of the instrument cluster. I had it working for a while with a little different style socket, but it has lost connection again. When it loses contact the turn signal bulbs will flash very dimly and fast. I believe that the circuit needs the resistance from the indicator bulb to function properly.

Has anyone experienced this problem and what were your solutions? I have not tried to find a replacement cluster circuit panel.

Thanks in advance,

Seabee

 

[GAmes]

That is a new failure. I don't think the plastic circuit board is detachable from the housing. I do have one if you want it. Where are you? I'm packing for a little drive to TN, then to IL, then OR, then WA then MO and back to TX. You might be close to my route.

 

[Seabee]

Thanks GAmes. I'm in Sesser, IL just off of I-57 and 20 Miles south of I-64 at Mt Vernon.

It looks like the "circuit board" might be replaceable, but probably easier to just replace the entire cluster housing. The housing is fine, the problem is maintaining electrical contact with the two little tabs on the bulb socket to the "circuit board." I've had this problem before on 70's era Ford pickups.

Sounds like a great trip you have planned. I grew up in Bend, OR.

 

[GAmes]

If you don't have it resolved in a couple weeks PM me. We can work out getting mine shipped to you.

 

[GAmes]

I guess I ought to only read posts when I'm conscious. I'm stopping in Mt. Vernon. That is my second pickup point. I'll put the cluster housing in the truck. Pm me your phone number. I plan on being there Wed afternoon.

 

[GAmes]

I'm ahead of schedule. Looking at Wed morning now.

 

[Seabee]

Thanks for the instrument cluster Gary! I was able to get my dash light working with one of your bulb holders. Unfortunately, I still have the blinker problem! I've done all of the normal troubleshooting (cleaning grounds, running temporary ground to the battery, checked voltage at bulb, etc.) but no joy. The left side flashes normally, but the right is fast and very dim. When I turn on the headlights it doesn't flash at all.
I'm inclined to think the flasher switch in the column has an issue, but I hate just changing parts to change parts! I think that I need to do some cipherin'.........

 

[petersonj]

Turn on your emergency flashers (the emergency flasher is not load sensitive) and check that the front right bulb and the rear right bulb are burning at the proper intensity. My bet is that one is burning dimly. If so, that bulb likely has a poor ground.

- John

 

[brucejohnson]

Thanks for the instrument cluster Gary! I was able to get my dash light working with one of your bulb holders. Unfortunately, I still have the blinker problem! I've done all of the normal troubleshooting (cleaning grounds, running temporary ground to the battery, checked voltage at bulb, etc.) but no joy. The left side flashes normally, but the right is fast and very dim. When I turn on the headlights it doesn't flash at all.
I'm inclined to think the flasher switch in the column has an issue, but I hate just changing parts to change parts! I think that I need to do some cipherin'.........

What petersonj said...
Many causes come to mind. When you say the right turn signal flashed fast and dim, are both R front and R rear turn signals dim? Sounds like a burned out signal element and possibly bad ground. Corrosion in the bulb socket. Wrong bulb installed. I have seen similar indications where one bulb element burned out and arced over the second element. Then there is the flasher itself. I don't remember when the flashers went from mechanical to electronic.

 

[Seabee]

Thanks for the idea on the 4 ways. I'll try that tomorrow. I believe that is a separate flasher from the turn signals (or they were in the good old days!). I don't think the flasher would only effect one side anyway.
Both front and rear are dim. I jumpered the front bulb ground directly to the battery with no change. I cleaned the socket bulb connectors and tried a different bulb.
I recently installed the sport ram headlight conversion and the brite box light set up. The signals worked correctly after the conversion for a short while, but I wouldn't think that the conversion set up would cause a blinker problem?

 

[brucejohnson]

Thanks for the idea on the 4 ways. I'll try that tomorrow. I believe that is a separate flasher from the turn signals (or they were in the good old days!). I don't think the flasher would only effect one side anyway.
Both front and rear are dim. I jumpered the front bulb ground directly to the battery with no change. I cleaned the socket bulb connectors and tried a different bulb.
I recently installed the sport ram headlight conversion and the brite box light set up. The signals worked correctly after the conversion for a short while, but I wouldn't think that the conversion set up would cause a blinker problem?

With this information it acts like there is a large current draw in the right side turn signal circuit. 4 way lighting check will help a lot. Could be any number of things, like chafed wire, trailer tow electric socket issue, instrument circuit board issue, front or rear bulb turn signal/brake element broken and shorting through the running/parking light ground side (this one I have experienced on two occasions). Do the headlights work properly in low and high beam? Only the right side will not flash with lights on? Where did you attach the Brite Box?
On EDIT: When you check the turn signal lights, be sure to check both elements for proper activity. A bad ground can cause the "other" element to conduct through its circuity to its associated ground, adding additional elements, front and rear, which will glow dimly, and add current. When the lights are turned on it creates potential at the bad point and cancels out the flasher circuit. Hope I stated it in an understandable way.

 

[Seabee]

I tried the 4-ways tonight. They worked great. I removed the multi-function switch and did a continuity and resistance check on it. Sure enough, there was a lot of resistance between two of the right turn terminals (44 ohms). I am going to pick up a new switch tomorrow. The wiring looked great as far as I could trace it in the cab.
My truck is actually a cream puff that stays in the garage 95% of the time. I mostly use it for towing my camper, bike trailer or car trailer. It only has 138K on it and has been seriously cared for. It bothers me when it even has a case of the sniffles! LOL Thanks for the input guys.

 

[Seabee]

Well, I replaced the multi-function switch and no improvement. I am no rookie to electrical diagnostics, but I have to admit that I am at a dead end. The 4-ways work great and the left turn works great. The right turn is fast and dim. I have checked all of the usual suspects, grounds, bulbs, connections, etc, but in truth for the 4-ways to work great the bulbs, wiring, etc. has to be good. The only thing I can think of is with the 4-ways on, whatever problem the right turn has is being accommodated/compensated for via the left turn circuit. Once the power leaves the multi-function switch, either right turn or 4-way, it travels through the same wire to the bulb. Am I not seeing the forest for the trees? Thanks in advance..

 

[brucejohnson]

Well, I replaced the multi-function switch and no improvement. I am no rookie to electrical diagnostics, but I have to admit that I am at a dead end. The 4-ways work great and the left turn works great. The right turn is fast and dim. I have checked all of the usual suspects, grounds, bulbs, connections, etc, but in truth for the 4-ways to work great the bulbs, wiring, etc. has to be good. The only thing I can think of is with the 4-ways on, whatever problem the right turn has is being accommodated/compensated for via the left turn circuit. Once the power leaves the multi-function switch, either right turn or 4-way, it travels through the same wire to the bulb. Am I not seeing the forest for the trees? Thanks in advance..

You are probably correct about the 4 way being "compensated" via the left side circuitry. Using the KISS principle, the easiest, simplest scenario to account for your malfunction is a bad ground at one end or the other (front or rear) bulb sockets. The high (brake and turn signal) and low (parking and tail) light bulb elements are tied to ground through the bulb socket. If one bulb looses its ground the potential will seek the least resistance path to ground, which would be through the low filament and seek ground through any additional bulbs low filament in the overall circuit. Those "included" filaments may illuminate ever so slightly as the current passes thru them. If the high element is illuminated you may not see the lower intensity glow unless you are looking directly into the bulb. These additional elements added due to the lack of expected ground will act like hooking up a trailer with a bazillion bulbs for turn signals and draw extra current causing the flasher to heat up rapidly, in turn speeding up the flash cycle. Once you turn on the parking or headlights the newly found ground through the low intensity filaments now changes potential from a ground to a positive value, thereby ceasing current flow and turning off the illumination. Hope this makes sense. Good luck.

Question: With the headlights OFF and the right turn signals activated and rapidly flashing, what happens, front and rear lighting, when you apply the brakes and the brake lights come on?

 

[Seabee]

Thanks for the reply Bruce. I have not checked the reaction with the brake lights applied. Another good idea.

I too am a firm believer in the KISS principle! Somehow it is easier to apply to other people's vehicles than my own!

I would also believe it to be a ground problem, but I tapped in and ran a direct ground to each bulb just to make sure. No difference! To further support your theory, I did see the EGT gauge needle jump a few times as the right side was "flashing." It is obviously trying to find a ground path.

I'm beginning to wonder if the ground wire is broken inside one of the right side bulb sockets? I'll check them for continuity tomorrow.....

 

[brucejohnson]

Thanks for the reply Bruce. I have not checked the reaction with the brake lights applied. Another good idea.

I too am a firm believer in the KISS principle! Somehow it is easier to apply to other people's vehicles than my own!

I would also believe it to be a ground problem, but I tapped in and ran a direct ground to each bulb just to make sure. No difference! To further support your theory, I did see the EGT gauge needle jump a few times as the right side was "flashing." It is obviously trying to find a ground path.

I'm beginning to wonder if the ground wire is broken inside one of the right side bulb sockets? I'll check them for continuity tomorrow.....

With the turn signal circuit energized take a voltage reading from the bulb's metal base to a known good ground. If there is a break you will read applied voltage. If the ground is sound you shouldn't get any, or very little voltage reading. Both front and rear need to be checked.
Oh, those silly EGT gauges are just sooo sensitive to every electron in the vicinity ...

 

[Seabee]

Well, the brake lights work properly. The bulb ground test showed no voltage. The ohms check on the bulb sockets was really good too.

The voltage at the socket was only .4 to 4.5 volts, fluctuating with the flasher. Any other ideas Bruce? I am just about tapped out.

 

[brucejohnson]

No headlights on...So front and rear socket and bulb checks are OK, swap rear bulb?...Did the front turn signals illuminate a tiny bit when you activated the brakes with the right turn signal activated? Also, with the right turn signal activated you say the brake lights work properly? That would mean ONLY the left brake light illuminates and the right continues to flash rapidly?
Now to shoot from the hip, have you swapped a flasher relay in? Do you have a 7 way trailer harness, disconnect if you do?
The 4.5 volts tell me there is an added resistance dropping the load somewhere. That would happen with a missing ground by adding the "supplemented" elements in series along with the additional parallel bulbs in the affected circuit. Something is drawing/redirecting/shorting those poor electrons. Old add on splices in the harness, i.e. scotch locks? Corroded contacts in the firewall connector or associated plugs: disconnect the turn signal and rear tail light plugs and measure the voltage at the front and rear plugs. A wire with several broken strands not allowing full current to pass - but that would reduce current,,,? Do you have a tilt steering wheel? Inspect and Jiggle the steering column wiring harness...
I don't have a 97 wiring diagram any more but can review the 74, 75, 76, 98.5 and 2002 that I still have.

 

[brucejohnson]

Seabee,

Which turn signal bulbs do you have installed in front and rear, 1157 or 1034? Many years ago when the 1157 came out we would occasionally get someone come in with a rapid flash on one side. Sometimes it would be due to a heavy duty flasher with a 1034 bulb installed in lieu of an 1157. (or was it the other way around...Darned...Getting old ain't no darned fun. Keep forgetting things that was well engrained back then). Other times a mis-keyed bulb installation where it went in backward and twisted with little effort due to poor bulb manufacture or weak/worn aluminum socket. I would check for the proper bulbs and installation and maybe consider replacement of both front and rear bulbs just for grins and maybe a flasher unit too. They are cheap enough. I would start with a close review/inspection of the system components first.

I am most curious on the Rt turn signal operation regarding both sides' tail/turn lights function with the headlights OFF, Rt Turn signals ON and brake lights ON, then with headlights ON.

In addition to post #18 suggestions here are some more detailed tests to consider:

In the dark of night turn on the right turn signal. Walk around the truck observing all external lights for any indication of illumination, dim or bright. Are side marker lights working properly? Try the same thing for the left turn signal. then do both again with the parking lights then headlights on. Looking for errant electrons wandering in the wayward paths of lesser resistance.

Disconnect the Brite Box and, if possible, connect to original configuration to eliminate the Brite Box and check the operation of the turn signals. Re connect if no change.

Next:
Headlights off.
Remove Rt front turn signal bulb.
Observe filaments' physical conditions.
Confirm all bulb continuities with an ohmmeter.
Activate Rt turn signal.
Observe light actions. Are they still rapidly flashing, or not flashing?
If flashing measure voltages at turn signal and parking light contacts to bulb socket ground.
Have someone apply the brake to energize the brake lights, note light actions front & rear, and measure the contacts' voltages again.
Release brakes.
Turn on headlights and measure all contact voltages again.
Turn headlights OFF.
Turn right turn signal OFF.
Check bulb socket case to chassis ground for continuity as well as ground contact points for tightness and corrosion.
Re-install front TS bulb.

Repeat the above steps with the Rt rear bulb removed and measure Rt rear turn signal and parking light contact voltages without and with application of brake lights and headlights, also observing front lights' filaments for dim glow.

NOTE: When viewing any bulb activity it should be a naked bulb and shielded from as much light as possible to observe both elements for even the dimmest light activity. Include observing license plate and side marker lights. You may see spots for a while attempting to see any dim illumination of the parking/tail light filament with the bright element glaring away. I would even remove both front and rear left side turn signal/parking lights from their lenses and observe the elements for very, very dim illumination.
Checking continuity from socket pins to ground would be a questionable test due to all the lamps in the circuits. Although you could compare readings and if something is significantly out to lunch in the readings, devote more time in that area. Removing them would be time consuming and possibly cause unintended boo-boos. Best used when all else fails.

If any observed voltage is low with the above tests, disconnect the light housing/socket from the harnesses and measure voltages directly at the truck-side plug contacts to chassis ground.

Open the 7 way tow electrical connector
Check for contact and connection conditions.
If it was installed using scotch-locks, check for splice and wire condition.
If factory installed, check harness plug condition.

On EDIT: When performing the voltage tests above be sure to include the 7 way tow electrical connector for voltage checks.
Maybe try hooking up a trailer to confirm operations before testing. This would add additional load and ground circuits to aide in TS. Disconnect prior to performing above tests.

I don't believe the turn signal indicator bulb would cause this issue. 193, 194, 168, 151(?) should all work.

Sorry for all the work suggested. Just trying to help narrow the issue down.

Best of luck.

 

[Seabee]

Good morning Bruce,

I am leaving for Arkansas in a few days and I don't mind saying that my mind is a little overloaded right now! I have never had so much trouble solving an electrical issue.
Regarding the brake light test, with the right turn on and brakes applied there was no illumination on the right turn/brake light bulb. With the turn signal in neutral, both brake lights illuminated properly.

FYI, this pickup takes the flat "blade" style bulbs. They are both 1157's and I have replaced both (twice just to make sure).

The kicker that still haunts me is that on 4-way or just brakes the bulbs light up properly. The same wire is used to illuminate the bulbs from the multi-function switch on. With such a voltage drop on right turn, one would think that even the assistance of the left side couldn't over-power the problem in 4-way operation.
The ground wires are very good on both bulbs.

I have wiring diagrams as provided in my Chilton's manual. They are actually quite good in detail.

I really appreciate the time you have taken to assist, but I think that I'm going to take a few days away from it, enjoy a visit with my Daughters, and get as far back to the basics (KISS) as I can on this problem!

Happy Thanksgiving Bruce, Seabee (Joe)